02718nas a2200193 4500008004100000022001400041245017700055210006900232260007100301300001400372490000700386520191400393100002102307700001702328700001702345700001702362700002002379856012502399 2010 eng d a1528-748300aStructural diversity in partially fluorinated metal organic frameworks (F-MOFs) composed of divalent transition metals, 1,10-phenanthroline, and fluorinated carboxylic acid0 aStructural diversity in partially fluorinated metal organic fram a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcMAR a1351-13630 v103 a

Seven new partially fluorinated metal-organic frameworks (F-MOFs) have been synthesized under different solvothermal conditions (H(2)O or N,N-dimethylformamide (DMF)) from transition metal cations [Zn(II), Co(II), and Mn(II)], 1,10-phenanthroline (phen), and 4,4'-(hexafluoroisopropylidene) bis(benzoic acid) (C(17)H(10)F(6)O(4), H(2)hfbba) to determine the influence of reaction conditions on the formation of metal-organic frameworks. This family of materials displays a striking degree of structural similarity depending on the solvent of synthesis. Of the seven materials, two contain three-dimensional connectivity: Co(3)(hfbba)(6)(phen)(2) (F-MOF-6) and Mn(3)(hfbba)(6)(Phen)(2) (F-MOF-10). Three materials are one-dimensional structures: Zn(hfbba)(0.5)(phen)(HCO(2)) (F-MOF-8), Mn(Hhfbba)(2)(Phen) (F-MOF-11), and [Mn(hfbba)(2)(dm-phen)]center dot(H(2)O) (F-MOF-11A). Lastly, Co(hfbba)(phell)(2)center dot 2(H(2)hfbba)(H(2)O)(HCO(2)) (F-MOF-7) and Zn(hfbba)(phen)(2)center dot 2(H(2)hfbba) (H(2)O)-(HCO(2)) (F-MOF-9) are discrete zero-dimensional molecular complexes. F-MOF-6 and -10, which feature it three-dimensional (3D) framework with pcu topolgy are formed in DMF like F-MOF-8 and at 85 degrees C. The remaining F-MOFs are formed by a solvothermal reaction at 120 degrees C in water. F-MOF-7 and -9 are isostructural discrete zero-dimensional molecular complexes (a similar to 19.5; b similar to 13.7; c similar to 26.2/29.6 angstrom; beta similar to 99.9/120.04; V similar to 6840 angstrom(3)). All these F-MOFs were structurally determined by single-crystal X-ray diffraction. Solid-state properties such its UV-vis and the thermal stability of F-MOF-6 to -11A have also been studied. Insight into the factors influencing the preferred crystallization of a specific complex over others has been obtained from full quantum chemical (QM) calculations using density functional theory (DFT).

1 aPachfule, Pradip1 aDey, Chandan1 aPanda, Tamas1 aVanka, Kumar1 aBanerjee, Rahul uhttps://library.ncl.res.in/content/structural-diversity-partially-fluorinated-metal-organic-frameworks-f-mofs-composed-002217nas a2200241 4500008004100000022001400041245014100055210006900196260006700265300001200332490000700344520126700351653002401618653002701642653002401669653002401693653002601717653003701743653002701780100002001807700001701827856013101844 2013 eng d a0192-865100aSolving the problem of negative populations in approximate accelerated stochastic simulations using the representative reaction approach0 aSolving the problem of negative populations in approximate accel a111 RIVER ST, HOBOKEN 07030-5774, NJ USAbWILEY-BLACKWELLcFEB a394-4040 v343 a

Methods based on the stochastic formulation of chemical kinetics have the potential to accurately reproduce the dynamical behavior of various biochemical systems of interest. However, the computational expense makes them impractical for the study of real systems. Attempts to render these methods practical have led to the development of accelerated methods, where the reaction numbers are modeled by Poisson random numbers. However, for certain systems, such methods give rise to physically unrealistic negative numbers for species populations. The methods which make use of binomial variables, in place of Poisson random numbers, have since become popular, and have been partially successful in addressing this problem. In this manuscript, the development of two new computational methods, based on the representative reaction approach (RRA), has been discussed. The new methods endeavor to solve the problem of negative numbers, by making use of tools like the stochastic simulation algorithm and the binomial method, in conjunction with the RRA. It is found that these newly developed methods perform better than other binomial methods used for stochastic simulations, in resolving the problem of negative populations. (C) 2012 Wiley Periodicals, Inc.

10aapproximate methods10abinomial distributions10aGillespie algorithm10aKinetic Monte Carlo10aPoisson distributions10arepresentative reaction approach10aStochastic simulations1 aKadam, Shantanu1 aVanka, Kumar uhttps://library.ncl.res.in/content/solving-problem-negative-populations-approximate-accelerated-stochastic-simulations-using-001290nas a2200193 4500008004100000022001400041245012900055210006900184260011000253300001400363490000700377520046700384100003100851700002300882700002300905700001700928700002100945856013000966 2013 eng d a1359-734500aSynthesis of palmyrolide A and its cis-isomer and mechanistic insight into trans-cis isomerisation of the enamide macrocycle0 aSynthesis of palmyrolide A and its cisisomer and mechanistic ins aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcMAR a3342-33440 v493 a

Concise and protecting-group free synthesis of ent-palmyrolide A and (-)-cis-palmyrolide A were achieved starting from commercially available (S)-citronellal. The key fragment of palmyrolide A, ``(5S,7S)-7-hydroxy-5,8,8-trimethylnonanamide'', which makes up the most challenging part of the target molecule, was prepared in just three steps. A plausible mechanism for the trans-cis isomerization of the double bond in the macrocycle has been investigated.

1 aPhilkhana, Satish, Chandra1 aSeetharamsingh, B.1 aDangat, Yuvraj, B.1 aVanka, Kumar1 aReddy, Srinivasa uhttps://library.ncl.res.in/content/synthesis-palmyrolide-and-its-cis-isomer-and-mechanistic-insight-trans-cis-isomerisation-001834nas a2200253 4500008004100000022001400041245015100055210006900206260007700275300001400352520086900366653002001235653002501255653001301280653002401293100001901317700001801336700001801354700001601372700001701388700002401405700002301429856012801452 2014 eng d a1434-193X00aSynthesis of alpha,beta-unsaturated delta-lactones by vinyl acetate mediated asymmetric cross-aldol reaction of acetaldehyde: mechanistic insights0 aSynthesis of alphabetaunsaturated deltalactones by vinyl acetate aBOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANYbWILEY-V C H VERLAG GMBHcAUG a5247-52553 a

A tandem asymmetric cross-aldol reaction involving the in situ generation of acetaldehyde from vinyl acetate has been developed that may resolve the challenges associated with the handling of acetaldehyde. The simple protocol, mild reaction conditions and unique harmony of an organocatalyst with a biocatalyst make this method a valuable tool for the synthesis of asymmetric beta-hydroxy aldehydes. By using this methodology we have accessed alpha,beta-unstaurated delta-lactones as well as isochromenones with high enantioselectivities from both asymmetric beta-hydroxy aldehydes and ketones. Systemic density functional theory (DFT) studies were also performed to gain mechanistic insights into the role of hydrogen bonding in the asymmetric cross-aldol reaction of acetaldehyde and in the key cis/trans isomerisation step in the synthesis of d-lactones.

10aAldol reactions10aasymmetric catalysis10alactones10areaction mechanisms1 aKumar, Manjeet1 aKumar, Arvind1 aRizvi, Masood1 aMane, Manoj1 aVanka, Kumar1 aTaneja, Subhash, C.1 aShah, Bhahwal, Ali uhttps://library.ncl.res.in/content/synthesis-alphabeta-unsaturated-delta-lactones-vinyl-acetate-mediated-asymmetric-cross-001813nas a2200193 4500008004100000022001400041245010700055210006900162260011000231300001600341490000600357520101100363100002101374700002401395700002801419700001701447700002401464856013101488 2015 eng d a2046-206900aSilica microspheres containing high density surface hydroxyl groups as efficient epoxidation catalysts0 aSilica microspheres containing high density surface hydroxyl gro aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcFEB a21125-211310 v53 a

Uniformly sized silica microspheres were synthesized by a hydrolysis-condensation method. The obtained material was etched with a mild aqueous potassium hydroxide solution for different periods of time to break their Si-O-Si bonds and increases the density of hydroxyl groups on their surfaces. The resulting materials were then used as transition metal-free catalysts for oxidation of olefins in the presence of hydrogen peroxide as a green oxidant. The materials were thoroughly characterized using various physicochemical techniques. These highly populated hydroxyl groups on the surface of silica microspheres were proven to be responsible for excellent conversion (up to 93%) and epoxide selectivity (up to 100%) for various olefins. Quantum mechanical calculations also corroborate the experimental findings. Furthermore, both experimental and theoretical studies show that tertiary silanols were present at the active sites of the catalyst surface and were responsible for olefin epoxidation.

1 aChandra, Prakash1 aDoke, Dhananjay, S.1 aUmbarkar, Shubhangi, B.1 aVanka, Kumar1 aBiradar, Ankush, V. uhttps://library.ncl.res.in/content/silica-microspheres-containing-high-density-surface-hydroxyl-groups-efficient-epoxidation-001745nas a2200157 4500008004100000022001400041245008800055210006900143260007100212300001200283490000700295520113600302100001601438700001701454856011601471 2016 eng d a0020-166900aSmall molecule activation by constrained phosphorus compounds: insights from theory0 aSmall molecule activation by constrained phosphorus compounds in a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcJAN a558-5650 v553 a

An exciting new development in main group chemistry has been the use of a constrained, flat, phosphorus-based complex to mediate in reactions such as the dehydrogenation of ammonia borane (AB), and the activation of the NH bond in primary amines. Its importance is based on the fact that it shows that main group compounds, when properly designed, can be as effective as transition metal complexes for doing significant chemical transformations. What the current computational study, employing density functional theory (DFT), reveals is that a common, general mechanism exists that accounts for the behavior of the flat phosphorus compound in the different reactions that have been experimentally reported to date. This mechanism, which involves the mediation by a base as a proton transfer agent, is simpler and energetically more favorable than the previous mechanisms that have been proposed for the same reactions in the literature. It is likely that the knowledge gained from the current work about the chemical behavior of this phosphorus compound can be utilized to design new constrained phosphorus-based compounds.

1 aPal, Amrita1 aVanka, Kumar uhttps://library.ncl.res.in/content/small-molecule-activation-constrained-phosphorus-compounds-insights-theory-002509nas a2200241 4500008004100000245014200041210006900183260000800252300001400260490000700274520163100281100001701912700002401929700002401953700001601977700001701993700001902010700003502029700002202064700003002086700002402116856012702140 2017 eng d00aSecondary interactions arrest the hemiaminal intermediate to invert the modus operandi of schiff base reaction: a route to benzoxazinones0 aSecondary interactions arrest the hemiaminal intermediate to inv cAPR a4342-43510 v823 aDiscovered by Hugo Schiff, condensation between amine and aldehyde represents one of the most ubiquitous reactions in chemistry. This classical reaction is widely used to manufacture pharmaceuticals and fine chemicals. However, the rapid and reversible formation of Schiff base prohibits formation of alternative products, of which benzoxazinones are an important class. Therefore, manipulating the reactivity of two partners to invert the course of this reaction is an elusive target. Presented here is a synthetic strategy that regulates the sequence of Schiff base reaction via weak secondary interactions. Guided by the computational models, reaction between 2,3,4,5,6-pentafluoro-benzaldehyde with 2-amino-6methylbenzoic acid revealed quantitative (99%) formation of 5-methyl-2-(perfluoropheny01,2-dihydro-4H-benzo[d][1,3]oxazin-4-one (15). Electron donating and electron withdrawing ortho-substituents on 2-aminobenzoic acid resulted in the production of benzoxazinones 936. The mode of action was tracked using low temperature NMR, IN vis spectroscopy, and isotopic (O-18) labeling experiments. These spectroscopic mechanistic investigations revealed that the hemiaminal intermediate is arrested by the hydrogen-bonding motif to yield benzoxazinone. Thus, the mechanistic investigations and DFT calculations categorically rule out the possibility of in situ imine formation followed by ring-closing, but support instead hydrogen-bond assisted ring-closing to prodrugs. This unprecedented reaction represents an interesting and competitive alternative to metal catalyzed and classical methods of preparing benzoxazinone.1 aPatel, Ketan1 aDeshmukh, Satej, S.1 aBodkhe, Dnyaneshwar1 aMane, Manoj1 aVanka, Kumar1 aShinde, Dinesh1 aRajamohanan, Pattuparambil, R.1 aNandi, Shyamapada1 aVaidhyanathan, Ramanathan1 aChikkali, Samir, H. uhttps://library.ncl.res.in/content/secondary-interactions-arrest-hemiaminal-intermediate-invert-modus-operandi-schiff-base01130nas a2200193 4500008004100000022001400041245012900055210006900184260000900253300001400262490000700276520042800283100002600711700001500737700001700752700001900769700002400788856012400812 2019 eng d a1359-734500aSilylene induced cooperative B-H bond activation and unprecedented aldehyde C-H bond splitting with amidinate ring expansion0 aSilylene induced cooperative BH bond activation and unprecedente cMAR  a3536-35390 v553 a

The addition of HBpin to PhC(NtBu)(2)SiN(SiMe3)(2) (1) results in the cleavage of the B-H bond in a cooperative fashion across the Si and amidinate-C sites. The reaction of 1 with benzaldehyde led to C-H bond activation with amidinate ring expansion leading to a five-membered heterocycle. In case of 4-fluorobenzaldehyde, a C-C bond coupling takes place leading to a dioxasilolane derivative as the major product.

1 aSwamy, V., S. V. S. N1 aRaj, Vipin1 aVanka, Kumar1 aSen, Sakya, S.1 aRoesky, Herbert, W. uhttps://library.ncl.res.in/content/silylene-induced-cooperative-b-h-bond-activation-and-unprecedented-aldehyde-c-h-bond02090nas a2200193 4500008004100000245005500041210005300096260000800149300001600157490000700173520150800180100002401688700002601712700001501738700001701753700002401770700001901794856008301813 2019 eng d00a Synthesis and reactivity of a hypersilylsilylene 0 aSynthesis and reactivity of a hypersilylsilylene cAUG a10536-105420 v583 a

Stabilization of an amidinatosilylene with a bulky tris(trimethylsilyl)silyl substituent was realized with the preparation of PhC(NtBu)(2)Si{Si(SiMe3)(3)} (1) from PhC(NtBu)(2)SiHCl2 with K{Si(SiMe3)(3)} in more than 90% yield. The highly deshielded Si-29 NMR resonance (delta = 76.91 ppm) can be attributed to the absence of a pi-donating substituent. The molecular structure of 1 shows a trigonal-planar geometry around the Si-II center with a Si-II-Si-IV bond length of 2.4339(13) angstrom. A series of reactions of 1 with Me3NO, S, Se, and Te were performed. While siloxane derivatives (2 and 3) are obtained from reactions with Me3NO, silachalcogenones (4-6) are formed with other chalcogens. The presence of Si=E (E = S, Se, and Te) bonds in 4-6 have been confirmed by single crystal X-ray studies. Silaoxirane (7) formation was observed when 1 was treated with acetone, demonstrating the importance of the tris(trimethylsilyl)silyl group to kinetically and thermodynamically protect the silaoxirane derivative with less bulky substituents on the C atom.

1 aBisai, Milan, Kumar1 aSwamy, V., S. V. S. N1 aDas, Tamal1 aVanka, Kumar1 aGonnade, Rajesh, G.1 aSen, Sakya, S. uhttps://library.ncl.res.in/content/synthesis-and-reactivity-hypersilylsilylene01850nas a2200205 4500008004100000022001400041245011800055210006900173260000800242300001400250490000700264520113500271100001701406700002401423700001901447700001801466700001901484700001701503856012401520 2021 eng d a0276-733300aSubstrate, catalyst, and solvent: the triune nature of multitasking reagents in hydroboration and cyanosilylation0 aSubstrate catalyst and solvent the triune nature of multitasking cAPR a1104-11120 v403 a

A truly green chemical process would avoid the use of an external catalyst, while still achieving high efficiency. This has been realized in the very recent past for hydroboration, cyanosilylation, acetalization, and the aza-Michael addition, among other reactions. The current combined computational and experimental study unlocks the secret to how this highly desirable outcome is accomplished: one of the reactants in the process also acts as the catalyst. Specifically, this is shown (i) for the important hydroboration reaction, with pinacolborane (HBpin) as the hydroborating reagent and benzaldehyde, acetophenone, benzoic acid and p-methoxyphenylacetylene as the hydroborated substrates, and (ii) for cyanosilylation, with trimethylcyanosilane (TMSCN) as the cyanosilylating agent and benzaldehyde as the substrate. The mechanistic understanding thus gained has then been further exploited experimentally to bring hydroboration and cyanosilylation closer to experimental conditions in catalysis. These insights can potentially be expanded to the rapidly growing area of solvent-free and internal catalyst chemistry.

1 aDixit, Ruchi1 aBisai, Milan, Kumar1 aYadav, Sandeep1 aYadav, Vinita1 aSen, Sakya, S.1 aVanka, Kumar uhttps://library.ncl.res.in/content/substrate-catalyst-and-solvent-triune-nature-multitasking-reagents-hydroboration-and01724nas a2200193 4500008004100000022001400041245009200055210006900147260000800216300000700224490000800231520108600239100002401325700002101349700001701370700001701387700000501404856012101409 2021 eng d a0974-362600aSynthesis of four diastereomers of notoryne and their C-13 NMR chemical shifts analysis0 aSynthesis of four diastereomers of notoryne and their C13 NMR ch cSEP a760 v1333 aIn this manuscript we document the details of the synthesis of four diastereomers of notoryne. The synthesis of one of the diastereomer having a similar relative stereochemistry of substituents on the both THF rings like notoryne, however, being the relative stereochemistry between the bridging carbon of these two THF units is changed from anti to syn has been executed mainly to learn how the ring carbon chemical shifts vary with this change. Interestingly, the deviations are found mainly for the carbons of THF ring that bears the Br-group. In addition to this isomer, three more diastereomers having the relative stereochemistry of substituents on either of the THF rings varied have been also synthesized. All four diastereomers have been subjected for extensive NMR studies and their C-13 NMR chemical shifts have been compared with notoryne and laurendecumenyne B. In addition, chemical shifts for the four diastereomers along with these natural products were calculated with the help of DFT calculations and compared to the experimentally obtained chemical shift values.1 aSenapati, Sibadatta1 aDas, Shyamsundar1 aDixit, Ruchi1 aVanka, Kumar1 a uhttps://library.ncl.res.in/content/synthesis-four-diastereomers-notoryne-and-their-c-13-nmr-chemical-shifts-analysis01810nas a2200241 4500008004100000245012900041210006900170260000800239300000900247490000700256520098200263653001101245653003101256653000901287653001901296653001101315100001701326700002101343700003401364700001701398700002301415856013001438 2022 eng d00aSilver dependent enantiodivergent gold(i) catalysed asymmetric intramolecular hydroamination of alkenes: a theoretical study0 aSilver dependent enantiodivergent goldi catalysed asymmetric int cNOV a13920 v123 a

We report a theoretical study of the first silver-dependent enantiodivergent gold-catalysed reaction. The combination of a single chiral binuclear gold(I) chloride complex and silver perchlorate catalyses the asymmetric intramolecular hydroamination of alkenes and affords both enantiomers of the products by applying a simple solvent change from toluene to methanol. A gold-silver chloride adduct that occurs only in methanol appears to control the enantioinversion. If one gold atom coordinates and activates the alkene moiety, the other gold is included in an adduct with silver chloride, which coordinates a methanol solvent molecule and further interacts with the amine function. If the use of toluene implies free anions and affords (S)-enantiomer, methanol allows a proximal interaction with the amine, leads to an opposite stereodifferentiation of the two diastereomeric intermediates during the final protodeauration step and results in the (R)-enantiomer.

10aalkene10aenantiodivergent catalysis10aGold10ahydroamination10aSilver1 aDixit, Ruchi1 aSharma, Himanshu1 aAgbossou-Niedercorn, Francine1 aVanka, Kumar1 aMichon, Christophe uhttps://library.ncl.res.in/content/silver-dependent-enantiodivergent-goldi-catalysed-asymmetric-intramolecular-hydroamination01579nas a2200205 4500008004100000022001400041245014300055210007100198260000800269300001200277490000600289520081600295100002401111700002201135700001801157700002601175700001701201700002201218856013301240 2022 eng d a2052-412900aSilver-catalyzed [3 + 3]-annulation cascade of alkynyl alcohols and α,β-unsaturated ketones for the regioselective assembly of chromanes0 aSilvercatalyzed 3 3annulation cascade of alkynyl alcohols and αβ cJAN a802-8090 v93 aAn unprecedented Ag(i)-catalyzed [3 + 3]-annulation of alkynyl alcohols (5-hexyn-1-ols) and α,β-unsaturated ketones is reported to construct simple to complex chromanes. This transformation begins with hydroalkoxylation of alkynol through C–C triple bond activation to give cyclic-enol ether, followed by intermolecular 1,4-addition and intramolecular 1,2-addition of enol ethers onto the enone and oxidative aromatization or Grob-type elimination steps. Facile reaction conditions, broad substrate scope, good to excellent yields, and atom economy are the salient features of this protocol. Isolation of the active pyran-tethered cyclohexadiene reaction intermediate, additional supporting experiments, and DFT calculations strongly support the experimental findings and corroborate our proposed mechanism.1 aNakate, Ashwini, K.1 aThorat, Sagar, S.1 aJain, Shailja1 aKrishna, Gamidi, Rama1 aVanka, Kumar1 aKontham, Ravindar uhttps://library.ncl.res.in/content/silver-catalyzed-3-3-annulation-cascade-alkynyl-alcohols-and-%CE%B1%CE%B2-unsaturated-ketones01271nas a2200205 4500008004100000022001400041245011800055210006900173260000900242300001400251490000700265520055300272100001700825700002300842700001500865700001700880700001900897700001900916856013000935 2022 eng d a1359-734500aSubstitution at sp(3) boron of a six-membered NHC center dot BH3: convenient access to a dihydroxyborenium cation0 aSubstitution at sp3 boron of a sixmembered NHC center dot BH3 co cMAR  a3783-37860 v583 a

Herein, we have undertaken the synthesis and investigated the reactivity of a 6-membered saturated NHC borane adduct (1). Direct electrophilic halogenation of 1 with a stoichiometric amount of I-2 led to NHC boryl iodides, 6-SIDipp center dot BH2I (2) and 6-SIDipp center dot BHI2 (3), which were further reacted with various nucleophiles to give novel 6-SIDipp based mono and disubstituted boranes with OTf (4 and 6) or ONO2 (5 and 7) functional groups. The addition of Br-2/H2O to 1 smoothly results in a dihydroxyborenium cation (8).

1 aKundu, Gargi1 aAjithkumar, V., S.1 aRaj, Vipin1 aVanka, Kumar1 aTothadi, Srinu1 aSen, Sakya, S. uhttps://library.ncl.res.in/content/substitution-sp3-boron-six-membered-nhc-center-dot-bh3-convenient-access-dihydroxyborenium01712nas a2200253 4500008004100000022001400041245005700055210005600112260000800168300001500176490000700191520099700198653001701195653000801212653002201220653000901242100001801251700001701269700002501286700001701311700001901328700001901347856009201366 2023 eng d a1434-194800aSix-membered NHC stabilized monomeric zinc complexes0 aSixmembered NHC stabilized monomeric zinc complexes cJUL ae2023001670 v263 a

This paper describes the rare use of a 6-membered saturated N-heterocyclic carbene (NHC) known as 1,3-di(2,6-diisopropylphenyl) tetrahydropyrimidine-2-ylidene (abbreviated as 6-SI-Dipp) as a ligand in zinc chemistry. We report on the investigation of the reactions between 6-SI-Dipp and ZnX2, which resulted in a range of new monomeric 6-SIDipp center dot ZnX2 complexes (X=Et (1), Cl (2), Br (3), and I (4)). We also prepared a new NHC zinc complex where the two substituents of the zinc atom are different, 6-SIDipp center dot Zn(Et)Br (7) through the reaction of the proligand [6-SIDippH]Br with ZnEt2. We have observed that the reactions of complex 1 with sulfur and HBpin led to the removal of the ZnEt2 moiety, resulting in the formation of a C=S double bond and a B H activation product, respectively. Lastly, the reaction of 1 with five-membered NHCs led to the exchange of carbene and the formation of either 5-IDipp center dot ZnEt2 (8) or 5-SIDipp center dot ZnEt2 (9).

10aLewis adduct10aNHC10aX-ray diffraction10azinc1 aGour, Kritika1 aKundu, Gargi1 aDash, Soumya, Ranjan1 aVanka, Kumar1 aTothadi, Srinu1 aSen, Sakya, S. uhttps://library.ncl.res.in/content/six-membered-nhc-stabilized-monomeric-zinc-complexes03410nas a2200325 4500008004100000022001400041245017000055210006900225260000800294300001100302490000900313520226000322653002602582653002302608653001602631653002602647100003102673700002502704700002502729700002102754700002902775700001602804700002302820700001702843700002202860700002202882700002202904700002802926856013002954 2023 eng d a0022-286000aSynthesis, characterization, crystal structure, in silico and computational studies on a novel Schiff base derived from α-chlorocinnamaldehyde and 4-aminoantipyrine0 aSynthesis characterization crystal structure in silico and compu cOCT a1359280 v12893 a

Schiff base, 4-(((1E,2Z)-2-chloro-3-phenylallylidene)amino)-1,5-dimethyl-2-phenyl-1,2 -dihydro-3H-pyrazol-3-one (1) was synthesized by condensation reaction of 4-aminoantipyrine and & alpha;-chlorocinnamaldehyde. The compound was characterized using Fourier-transform infrared spectroscopy (FT-IR), ultraviolet (UV)-visible spectroscopy, proton and carbon nuclear magnetic resonance spectroscopy (1H/13C NMR) and single-crystal X-ray diffraction analysis (SC-XRD). Density functional theory (DFT) was used to compute molecular parameters and also compared them with experimental data. The X-ray diffraction data revealed that the compound crys-tallizes as a monoclinic crystal system with a space group of C2/c and Z = 8, and is stabilized by C12-H12MIDLINE HORIZONTAL ELLIPSISO1, and C8-H8AMIDLINE HORIZONTAL ELLIPSISO1 intramolecular hydrogen bonds. The presence of a distinctive azomethine C = N bond length N3-C12 of 1.283(3) & ANGS;, and 1640 cm-1 stretching vibration in the FT-IR spectrum are evidence of the formation of a Schiff base. The computational result indicates that the ionization energy (IE), and electron affinity (EA) values for the molecule are 4.025 and 2.110 eV, respectively. The positive value of EA suggests that the addition of an electron to the molecule would be an exothermic process. The evaluated energy is relatively low and is an expression of the ease of electron transfer from the highest occupied molecular orbital (HOMO) to the lowest unoccupied molecular orbital (LUMO). Hirsfeld surface map over dnorm and curvedness surface indicated the presence of 7C-7C stacking while the shape factor index suggests donor and acceptor intermolecular C-H-7C. Analysis of Hirsfeld surfaces concerning the fingerprint indicated a minimal contribution from the de -di pair and reveals H–H as a major contribution to the Hirsfeld surface. However, the molecular packing did not confirm H–H as a significant contributor the packing. Docking calculations on the compound showed average theoretical binding energies toward aromatase (-5.99 & PLUSMN; 0.34 kcal/mol) and fibroblast growth factor receptor (FGFR) (-17.57 & PLUSMN; 6.85 kcal/mol), indicating binding interactions with both protein targets.

10aComputational studies10amolecular modeling10aSchiff base10aX-ray crystallography1 aAdimudo, Hillary, Chijioke1 aAgu, Chidike, Justus1 aOkenyeka, Obinna, U.1 aEddy, Nnabuk, O.1 aDim, Ebubechukwu, Nnamdi1 aDege, Necmi1 aBonardd, Sebastian1 aVanka, Kumar1 aIbezim, Akachukwu1 aIdika, Digbo, Iku1 aDiaz, David, Diaz1 aObasi, Nnamdi, Lawrence uhttps://library.ncl.res.in/content/synthesis-characterization-crystal-structure-silico-and-computational-studies-novel-schiff01647nas a2200205 4500008004100000022001400041245010700055210006900162260000800231300001400239490000700253520092900260100002301189700002701212700001501239700001701254700002401271700001901295856012701314 2023 eng d a0276-733300aSynthesis of Si(IV)- and Ge(II)-substituted amines, hydrazone, and hydrazine from hypersilyl germylene0 aSynthesis of SiIV and GeIIsubstituted amines hydrazone and hydra cOCT a2983-29900 v423 a

This study investigates the reactivity of a hypersilyl germylene [PhC-(NtBu)(2)GeSi-(SiMe3)(3)] (1) with various organic compounds including azides, diazoalkanes, 1,2-diphenylhydrazine, and trifluoroacetophenone. The reactivity observed in these reactions is driven by the insertion of the organic fragment between a silicon and germanium bond. This leads to the formation of novel compounds, including an amine featuring three different substituents from three different elements of group 14. When reacting with Me3SiCHN2, we observed the insertion of the diazoalkane fragment in an end-on fashion into the Ge-Si bond. An analogous trend was observed in reactions with 1,2-diphenylhydrazine and trifluoroacetophenone, where the N-N and C-O fragments were inserted into the Ge-Si bond. Multinuclear NMR and single-crystal X-ray diffraction analyses were conducted to characterize the newly synthesized compounds.

1 aAjithkumar, V., S.1 aGhanwat, Pratiksha, B.1 aRaj, Vipin1 aVanka, Kumar1 aGonnade, Rajesh, G.1 aSen, Sakya, S. uhttps://library.ncl.res.in/content/synthesis-siiv-and-geii-substituted-amines-hydrazone-and-hydrazine-hypersilyl-germylene02139nas a2200193 4500008004100000022001400041245008200055210006900137260000800206300001400214490000700228520150100235100002501736700002101761700002701782700001501809700001701824856010401841 2024 eng d a0020-166900aSize matters: computational insights into the crowning of noble gas trioxides0 aSize matters computational insights into the crowning of noble g cFEB a4099-41070 v633 a

In pursuit of enhancing the stability of the highly explosive and shock-sensitive compound XeO3, we performed quantum chemical calculations to investigate its possible complexation with electron-rich crown ethers, including 9-crown-3, 12-crown-4, 15-crown-5, 18-crown-6, and 21-crown-7, as well as their thio analogues. Furthermore, we expanded our study to other noble gas trioxides (NgO(3)), namely, KrO3 and ArO3. The basis set superposition error (BSSE) corrected interaction energies for these adducts range from -13.0 kcal/mol to -48.2 kcal/mol, which is notably high for sigma-hole-mediated noncovalent interactions. The formation of these adducts was observed to be more favorable with the increase in the ring size of the crowns and less favorable while going from XeO3 to ArO3. A comprehensive analysis by various computational tools such as the mapping of the electrostatic potential (ESP), Wiberg bond indices (WBIs), Bader's theory of atoms-in-molecules (AIM), natural bond orbital (NBO) analysis, noncovalent interaction (NCI) plots, and energy decomposition analysis (EDA) revealed that the C-H center dot center dot center dot O interactions, as well as dispersion interactions, play a pivotal role in stabilizing adducts involving larger crowns. A noteworthy outcome of our study is the revelation of a coordination number of 9 for xenon in the complex formed between XeO3 and the thio analogue of 18-crown-6, which is higher than the largest number reported to date.

1 aDash, Soumya, Ranjan1 aSharma, Himanshu1 aTiwari, Mrityunjay, K.1 aGreb, Lutz1 aVanka, Kumar uhttps://library.ncl.res.in/content/size-matters-computational-insights-crowning-noble-gas-trioxides01079nas a2200205 4500008004100000022001400041245008300055210006900138260000800207300001600215490000700231520039700238100002500635700002200660700002300682700002100705700001700726700001800743856011200761 2025 eng d a1359-734500aSilylene-copper(i) catalysis: regioselective protoboration of terminal alkynes0 aSilylenecopperi catalysis regioselective protoboration of termin cDEC a19652-196550 v613 a

Herein, we report an efficient regioselective protoboration of the terminal alkynes catalyzed by newly synthesized silylene-copper(i)-aryl complexes. This method offers a broad substrate scope, good functional-group compatibility, and a gram-scale synthetic ability. The insight into the mechanistic cycle is also provided with the support of experimental and theoretical studies.

1 aKaulage, Sandeep, H.1 aShah, Brij, Kumar1 aPanday, Rishukumar1 aSharma, Himanshu1 aVanka, Kumar1 aKhan, Shabana uhttps://library.ncl.res.in/content/silylene-copperi-catalysis-regioselective-protoboration-terminal-alkynes01950nas a2200253 4500008004100000022001400041245009600055210006900151260000900220490000700229520108400236653004101320653002501361653001501386653003001401100002501431700002201456700002101478700001901499700001701518700002401535700002201559856011501581 2025 eng d a1861-472800aStudies on the stereoselective synthesis of sacubitril via a chiral amine transfer approach0 aStudies on the stereoselective synthesis of sacubitril via a chi cMAR 0 v203 a

We present a comprehensive account of our efforts directed towards the synthesis of sacubitril, a neprilysin inhibitor used in combination with valsartan and marketed as Entresto (TM). Our initial approach to the formal synthesis of sacubitril employed a chiral pool strategy, utilizing (S)-pyroglutamic acid as a key building block and Cu(I)-mediated Csp2-Csp3 cross-coupling as a key transformation. Further investigations led to the development of chiral amine transfer (CAT) reagents-based stereoselective synthesis. This involved the E-selective construction of gamma-ylidene-butenolide from readily available biphenyl bromide and 4-pentynoic acid, the conversion of this butenolide to its ene-lactam using chiral amine, and substrate-controlled diastereoselective reduction of ene-lactam using Et3SiH or Pd/C, H2 (overall chiral amine transfer) as key transformations. Antipodal lactam intermediates were synthesized using corresponding chiral amines, and the stereochemical outcomes during the ene-lactam reduction with Et3SiH were rationalized by DFT studies.

10aChiral Amine Transfer (CAT) approach10aChiral pool approach10aSacubitril10astereoselective synthesis1 aSadanande, Megha, V.1 aThorat, Sagar, S.1 aSharma, Himanshu1 aSingh, Geetika1 aVanka, Kumar1 aGonnade, Rajesh, G.1 aKontham, Ravindar uhttps://library.ncl.res.in/content/studies-stereoselective-synthesis-sacubitril-chiral-amine-transfer-approach01496nas a2200217 4500008004100000022001400041245012100055210006900176260000800245300001400253490000700267520072100274100002400995700002201019700002101041700001901062700001701081700002401098700002401122856013201146 2025 eng d a1528-748300aSynthesis and concomitant polymorphs of green fluorescence protein chromophore-anthracene-based fluorescent analogue0 aSynthesis and concomitant polymorphs of green fluorescence prote cFEB a1011-10220 v253 a

Controlled variations in fluorescence properties hold significant promise for applications in optical sensors, bioimaging, and advanced display devices. However, constructing multicolor fluorescent systems remains a challenge. In this study, we demonstrate the development of multicolor fluorescence by generating polymorphs of a novel green fluorescent protein chromophore analogue, which exhibits distinct photoluminescence emissions in the solid state. The observed emission variations are attributed to differences in molecular conformation due to variations in pi-stacking interactions between the polymorphs. This offers a novel approach to designing materials with tunable fluorescence properties.

1 aMali, Bhupendra, P.1 aDabke, Niteen, B.1 aDash, Soumya, R.1 aBiswas, Anupam1 aVanka, Kumar1 aManoj, Kochunnoonny1 aGonnade, Rajesh, G. uhttps://library.ncl.res.in/content/synthesis-and-concomitant-polymorphs-green-fluorescence-protein-chromophore-anthracene-based01993nas a2200337 4500008004100000022001400041245014700055210006900202260000800271300001100279490000900290520088200299653000801181653002501189653002001214653001401234653001601248653000901264100002101273700002201294700002501316700003101341700002501372700002101397700002201418700001701440700002101457700002401478700002401502856012901526 2025 eng d a0022-286000aSynthesis, crystal structure, DFT calculation and catalytic activity of a polymer complex of zinc(II) succinate with 2-amino-1,3,4-thiadiazole0 aSynthesis crystal structure DFT calculation and catalytic activi cAUG a1422740 v13383 a

A polymer complex of zinc(II) succinate with a 2-amino-1,3,4-thiadialole ligand, denoted as [Zn2L2(suc)2]n, was synthesized and characterized by NMR, ESI-MS, FTIR, and FT-Raman spectroscopy, TGA, and X-ray crystallography. The polymer complex crystallizes in the orthorhombic noncentrosymmetric Pna21 space group and features a five-coordinate zinc ion in a distorted spherical square pyramidal geometry. The Hirshfeld surface analysis was carried out to evaluate the intermolecular interactions. Additionally, computational studies were also conducted to assess the stability of the Zn polymer complex and analyze the electron density distribution of the HOMO and LUMO. The catalytic activity of our complex was tested, interestingly, that showed good results for Biginelli reactions with distinct substrate scope in good to high yield at mild reaction conditions.

10aDFT10aDihydropyrimidinones10aPolymer complex10asuccinate10aThiadiazole10azinc1 aNuralieva, Guzal1 aAlieva, Mushtariy1 aTorambetov, Batirbay1 aLeslee, Denzil, Britto Chr1 aSenthilkumar, Beeran1 aKaur, Simranjeet1 aDabke, Niteen, B.1 aVanka, Kumar1 aAshurov, Jamshid1 aKadirova, Shakhnoza1 aGonnade, Rajesh, G. uhttps://library.ncl.res.in/content/synthesis-crystal-structure-dft-calculation-and-catalytic-activity-polymer-complex-zincii01146nas a2200193 4500008004100000022001400041245011300055210006900168260000800237300001400245490000700259520045800266100001900724700002100743700001700764700002400781700001900805856012800824 2025 eng d a0276-733300aSynthesis of diamido N-heterocyclic imines (DAC = NH) via staudinger or reductive N-N bond cleavage approach0 aSynthesis of diamido Nheterocyclic imines DAC NH via staudinger  cMAY a1129-11330 v443 a

This report communicates the first examples of N-heterocyclic imines based on electrophilic diamido carbenes (DACs). While 2 is prepared by classical Staudinger synthesis, 4 is obtained via an unusual reductive N-N bond cleavage of an azine by HCl. The exocyclic C=N bond lengths in 2 and 4 are substantially shorter than those based on N-heterocyclic carbenes and cyclic (alkyl)(amino)carbene reflecting the electrophilic character of DACs.

1 aBalayan, Kajal1 aSharma, Himanshu1 aVanka, Kumar1 aGonnade, Rajesh, G.1 aSen, Sakya, S. uhttps://library.ncl.res.in/content/synthesis-diamido-n-heterocyclic-imines-dac-nh-staudinger-or-reductive-n-n-bond-cleavage01206nas a2200205 4500008004100000245011000041210006900151260000800220300001400228490000700242520046500249100002400714700002200738700002100760700002500781700002400806700001700830700002400847856012900871 2026 eng d00aSwitchable solid-state emission in GFP chromophore analogue cocrystals via competing AIE and ACQ pathways0 aSwitchable solidstate emission in GFP chromophore analogue cocry cMAR a1775-17800 v283 a

We present a crystal-engineering approach enabling switchable solid-state emission (green -> orange -> quenched) in GFP-chromophore analogue cocrystals. The coformer's electronic and supramolecular effect shifts the photophysical pathway: intramolecular CT in cocrystal-I (green) and cocrystal-III (quenched) and intermolecular CT in cocrystal-II, yielding orange emissions and highlighting cocrystallization's power for tunable luminophores.

1 aMali, Bhupendra, P.1 aDabke, Niteen, B.1 aSharma, Himanshu1 aDash, Soumya, Ranjan1 aManoj, Kochunnoonny1 aVanka, Kumar1 aGonnade, Rajesh, G. uhttps://library.ncl.res.in/content/switchable-solid-state-emission-gfp-chromophore-analogue-cocrystals-competing-aie-and-acq