01733nas a2200241 4500008004100000022001400041245012100055210006900176260000800245300001400253490000700267520090400274653001701178653001401195653002001209653003601229653002601265100001901291700001701310700001701327700001901344856012801363 2018 eng d a0947-653900aBeyond hydrofunctionalisation: a well-defined calcium compound catalysed mild and efficient carbonyl cyanosilylation0 aBeyond hydrofunctionalisation a welldefined calcium compound cat cJAN a1269-12730 v243 a

Organocalcium compounds have been reported as efficient catalysts for various transformations, for cases in which one of the substrates contained an E-H (E=B, N, Si, P) bond. Here, we look at the possibility of employing an organocalcium compound for a transformation in which none of the precursors has a polar E-H bond. This study demonstrates the utilization of a well-defined amidinatocalcium iodide, [PhC(NiPr)(2)CaI] (1) for cyanosilylation of a variety of aldehydes and ketones with Me3SiCN under ambient conditions without the need of any co-catalyst. The reaction mechanism involves a weak adduct formation between 1 and Me3SiCN leading to the activation of the Si-C bond, which subsequently undergoes sigma-bond metathesis with a C=O moiety. Such a mechanistic pathway is unprecedented in alkaline earth metal chemistry. Experimental and computational studies support the mechanism.

10aCa catalysis10acarbonyls10acyanosilylation10aDensity functional calculations10atransition-metal free1 aYadav, Sandeep1 aDixit, Ruchi1 aVanka, Kumar1 aSen, Sakya, S. uhttps://library.ncl.res.in/content/beyond-hydrofunctionalisation-well-defined-calcium-compound-catalysed-mild-and-efficient01179nas a2200217 4500008004100000022001400041245015600055210006900211260000800280300001400288490000700302520037300309100001900682700001700701700002100718700001900739700003400758700001700792700002300809856012900832 2020 eng d a2044-475300aCatalytic reductive deoxygenation of esters to ethers driven by hydrosilane activation through non-covalent interactions with a fluorinated borate salt0 aCatalytic reductive deoxygenation of esters to ethers driven by  cJUL a4586-45920 v103 a

We report the catalytic and transition metal-free reductive deoxygenation of esters to ethers through the use of a hydrosilane and a fluorinated borate BArF salt as a catalyst. Experimental and theoretical studies support the role of noncovalent interactions between the fluorinated catalyst, the hydrosilane and the ester substrate in the reaction mechanism.

1 aRysak, Vincent1 aDixit, Ruchi1 aTrivelli, Xavier1 aMerle, Nicolas1 aAgbossou-Niedercorn, Francine1 aVanka, Kumar1 aMichon, Christophe uhttps://library.ncl.res.in/content/catalytic-reductive-deoxygenation-esters-ethers-driven-hydrosilane-activation-through-non01390nas a2200169 4500008004100000022001400041245007500055210006900130260000900199300001400208490000700222520082100229100002601050700001701076700002201093856010501115 2020 eng d a1523-706000aTotal synthesis of beshanzuenone D and its epimers and abiespiroside A0 aTotal synthesis of beshanzuenone D and its epimers and abiespiro cNOV  a8561-85650 v223 a

A unified and protecting-group-free six-step total synthesis of bisabolane-type sesquiterpenoid beshanzuenone D and its stereoisomers and abiespiroside A using S-(+)-carvone as a common chiral-pool building block is disclosed. This synthetic route features chemoselective allylic chlorination of carvone, Au(I)-catalyzed cydoisomerization induced construction of furan from homopropargylic diol, substrate-controlled selective hydroxylation using Davis-oxaziridine, and dye-sensitized photo-oxidation (through O-1(2)) of hydroxyalkyl tethered furan to access oxaspirolactone as key transformations. A comprehensive set of NMR data along with DFT calculations, ECD spectra, and optical rotation measurements of the synthesized beshanzuenone D and its epimers were obtained to confirm absolute configurations.

1 aBorade, Balasaheb, R.1 aDixit, Ruchi1 aKontham, Ravindar uhttps://library.ncl.res.in/content/total-synthesis-beshanzuenone-d-and-its-epimers-and-abiespiroside01220nas a2200301 4500008004100000022001400041245015700055210006900212260000800281300001100289490000800300520020800308653002300516653001700539653001700556653001600573653001400589100002100603700002500624700002300649700001700672700001900689700002100708700002600729700001700755700001700772856012900789 2020 eng d a0162-013400aTris-heteroleptic ruthenium(II) polypyridyl complexes: Synthesis, structural characterization, photophysical, electrochemistry and biological properties0 aTrisheteroleptic rutheniumII polypyridyl complexes Synthesis str cFEB a1109030 v2033 a

{Three water-soluble tris-heteroleptic ruthenium(II) polypyridyl complexes [Ru(bpy)(phen)(bpg)](2+) (1), [Ru (bpy)(dppz)(bpg)]2+ (2), and [Ru(phen)(dppz)(bpg)]2+ (3) (where bpy = 2,2'-bipyridine

10aCircular dichroism10aCytotoxicity10afluorescence10aPolypyridyl10aruthenium1 aBhat, Satish, S.1 aKumbhar, Avinash, S.1 aPurandare, Neeraja1 aKhan, Ayesha1 aGrampp, Gunter1 aLoennecke, Peter1 aHey-Hawkins, Evamarie1 aDixit, Ruchi1 aVanka, Kumar uhttps://library.ncl.res.in/content/tris-heteroleptic-rutheniumii-polypyridyl-complexes-synthesis-structural-characterization01155nas a2200193 4500008004100000022001400041245012800055210006900183260000800252300001400260490000700274520044600281100002600727700002500753700001700778700001700795700002600812856012300838 2021 eng d a1477-052000aEasy and practical approach to access multifunctional cylcopentadiene- and cyclopentene-spirooxindoles via [3+2] annulation0 aEasy and practical approach to access multifunctional cylcopenta cMAY a4338-43450 v193 a

A highly regioselective [3 + 2] annulation of Morita-Baylis-Hillman (MBH) carbonates of isatin with aurone/thioaurone is developed. Spiroheterocycles such as spirooxindole cyclopentadiene and spirooxindole fused hydroxy cyclopentene derivatives are constructed in one pot by exploring the reactivity of Lewis bases. Combined experimental and density functional theory (DFT) calculations offered an insight into the reaction mechanism.

1 aWarghude, Prakash, K.1 aSabale, Abhijeet, S.1 aDixit, Ruchi1 aVanka, Kumar1 aBhat, Ramakrishna, G. uhttps://library.ncl.res.in/content/easy-and-practical-approach-access-multifunctional-cylcopentadiene-and-cyclopentene01850nas 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-hydroamination01959nas a2200193 4500008004100000022001400041245015000055210006900205260000800274300001600282490000700298520124400305100001701549700001701566700001901583700001701602700001901619856012701638 2022 eng d a1477-922600aVersatile chemistry of six-membered NHC with boranes: bromination at sp(3) borane, activation of the B-H bond of HBpin, and ring expansion of NHC0 aVersatile chemistry of sixmembered NHC with boranes bromination  cOCT a14452-144570 v513 a

The NHC.borane chemistry has been majorly restricted to imidazol-2-ylidene classes of carbenes. In our previous communication, we reported the synthesis of 6-SIDipp center dot BH3 [6-SIDipp = 1,3-di(2,6-diisopropylphenyl) tetrahydropyrimidine-2-ylidene] and its electrophilic substitution reaction with iodine. Here, we have shown selective bromination of a 6-SIDipp stabilized sp(3) B-H bond. Treatment of 1.2 equivalents of N-bromosuccinamide with 6-SIDipp center dot BH3 gives a mixture of mono- and disubstituted products 6-SIDipp center dot BH2Br (1) and 6-SIDipp center dot BHBr2 (2). However, the reactions with alkyl bromides or carbon tetrabromide resulted in 6-SIDipp center dot BH2Br (1) selectively. Exploration of the chemistry of 6-SIDipp with BHCl2 and 9-BBN (9-borabicyclo[3.3.1]nonane) led to mono-6-SIDipp adducts 3 and 6a. Furthermore, 6a undergoes ring expansion to afford a seven-membered product, 6b, under mild conditions. Unlike BHCl2 or 9-BBN, the B-H bond of HBpin undergoes oxidative addition upon reaction with 6-SIDipp, epitomizing the first example (7) of a B-H bond insertion at NHCs. The analogous reactivity with HBcat led to a tetra-hydropyrimidinium salt with B(cat)(2) as a counteranion (8).

1 aKundu, Gargi1 aDixit, Ruchi1 aTothadi, Srinu1 aVanka, Kumar1 aSen, Sakya, S. uhttps://library.ncl.res.in/content/versatile-chemistry-six-membered-nhc-boranes-bromination-sp3-borane-activation-b-h-bond02001nas a2200289 4500008004100000022001400041245010500055210006900160260000800229490000700237520101800244653002201262653002701284653002201311653001601333653002301349100002901372700003301401700001801434700001701452700002001469700002101489700002001510700002401530700003001554856012701584 2023 eng d a1433-785100aOligothiophene-ring-strapped perylene bisimides: functionalizable coaxial donor-acceptor macrocycles0 aOligothiopheneringstrapped perylene bisimides functionalizable c cJAN0 v623 a

Aesthetic designs from nature enable new knowledge to be gained and, at the same time, inspire scientific models. In this context, multicomponent macrocycles embody the advantage of precisely positioning the structural units to achieve efficient communication between them. However, the construction of a functionalizable macrocycle for ultrafast charge separation and stabilization has not been attempted. Herein, we report the synthesis, crystal structure, and transient absorption of a new functionalizable macrocycle consisting of an oligothiophene-ring-strapped perylene bisimide. Transient absorption results point to a sequential improvement in charge separation and stabilization from the macrocycle to the corresponding linear dimer and 2D polymer due to the unique design. Our macrocycle design with a supportive spatial arrangement of the donor and acceptor units will inspire the development of more complex synthetic systems with exciting electron-transfer and charge-separation features.

10aCharge Separation10aDonor-Acceptor Systems10aElectron Transfer10aMacrocycles10aPerylene Bisimides1 aVeer, Sairam, Dnyaneshwa1 aWakchaure, Vivek, Chandrakan1 aAsokan, Kiran1 aDixit, Ruchi1 aGoswami, Tanmay1 aSaha, Ramchandra1 aGonnade, Rajesh1 aGhosh, Hirendra, N.1 aBabu, Sukumaran, Santhosh uhttps://library.ncl.res.in/content/oligothiophene-ring-strapped-perylene-bisimides-functionalizable-coaxial-donor-acceptor01964nas a2200253 4500008004100000022001400041245011800055210006900173260000800242490000600250520107500256653002001331653001901351653003101370653002501401653001901426100001801445700002701463700001701490700001701507700003001524700002701554856012901581 2023 eng d a2367-093200aVisible-light-active unsymmetrical squaraine dyes with 1 V of open-circuit voltage for dye-sensitized solar cells0 aVisiblelightactive unsymmetrical squaraine dyes with 1 V of open cMAY0 v73 a

A series of alkyl-group-functionalized, aniline- and indoline-donor-based, unsymmetrical visible-light-active squaraine dyes, AM1-3, were designed and synthesized. Dye-sensitized solar cell (DSSC) devices were fabricated with both I-/I-3(-) and [Cu(tmby)(2)](+/2+) electrolytes. DSSC devices sensitized with the AM1 and AM2 dyes showed relatively high-power conversion efficiency of 7.44 % and 7.22 %, respectively with I-/I-3(-) in the absence of chenodeoxycholic acid (CDCA) than those of the AM3 dye (5.41 %). The [Cu(tmby)(2)](+/2+) electrolyte along with poly(3,4-ethylenedioxythiophene) (PEDOT) as cathode material showed excellent open-circuit potentials (V-OC) of 1030, 1025, and 1001 mV with the DSSC efficiency of 8.05 %, 7.96 %, and 5.84 %, respectively, for the AM1, AM2, and AM3 dyes in the absence of CDCA. Here, the AM1 dye exhibited the maximum DSSC efficiency of 8.05 % and V-OC of 1030 mV, which is the highest obtained efficiency and V-OC for the visible-light active zwitterionic unsymmetrical-squaraine dye with copper-based electrolyte.

10aCu electrolytes10adihedral angle10aDye-sensitized solar cells10aopen circuit voltage10asquaraine dyes1 aSingh, Amrita1 aSingh, Ambarish, Kumar1 aDixit, Ruchi1 aVanka, Kumar1 aKrishnamoorthy, Kothandam1 aNithyanandhan, Jayaraj uhttps://library.ncl.res.in/content/visible-light-active-unsymmetrical-squaraine-dyes-1-v-open-circuit-voltage-dye-sensitized03030nas a2200205 4500008004100000022001400041245018300055210006900238260000800307300001600315490000600331520222200337100001802559700002702577700001702604700001702621700003002638700002702668856012902695 2024 eng d a2470-134300aEffect of position of donor units and alkyl groups on dye-sensitized solar cell device performance: indoline-aniline donor-based visible light active unsymmetrical squaraine dyes0 aEffect of position of donor units and alkyl groups on dyesensiti cMAR a16429-164420 v93 a

Indoline (In) and aniline (An) donor-based visible light active unsymmetrical squaraine (SQ) dyes were synthesized for dye-sensitized solar cells (DSSCs), where the position of An and In units was changed with respect to the anchoring group (carboxylic acid) to have In-SQ-An-CO2H and An-SQ-In-CO2H sensitizers, AS1-AS5. Linear or branched alkyl groups were functionalized with the N atom of either In or An units to control the aggregation of the dyes on TiO2. AS1-AS5 exhibit an isomeric pi-framework where the squaric acid unit is placed in the middle, where AS2 and AS5 dyes possess the anchoring group connected with the An donor, and AS1, AS3, and AS4 dyes having the anchoring group connected with the In donor. Hence, the conjugation between the middle squaric acid acceptor unit and the anchoring -CO2H group is short for AS2, AS5, and AK2 and longer for AS1, AS3, and AS4 dyes. AS dyes showed absorption between 501 and 535 nm with extinction coefficients of 1.46-1.61 x 10(5) M-1 cm(-1). Further, the isomeric pi-framework of An-SQ-In-CO2H and In-SQ-An-CO2H exhibited by means of changing the position of In and An units a bathochromic shift in the absorption properties of AS2 and AS5 compared to the AS1, AS3, and AS4 dyes. The DSSC device fabricated with the dyes contains short acceptor-anchoring group distance (AS2 and AS5) showed high photovoltaic performances compared to the dyes having longer distance (AS1, AS3, and AS4) with the iodolyte (I-/I-3(-)) electrolyte. DSSC device efficiencies of 5.49, 6.34, 6.16, and 5.57% have been achieved for AS1, AS2, AS3, and AS4 dyes, respectively; without chenodeoxycholic acid (CDCA), small changes have been observed in the device performance of the AS dyes with CDCA. Significant changes have been noted in the DSSC parameters (open-circuit voltage V-OC, short-circuit current J(SC), fill factor ff, and efficiency eta) for the AS5 dye while sensitized with CDCA and showed highest DSSC efficiency of 8.01% in the AS dye series. This study revealed the potential of shorter SQ acceptor-anchoring group distance over the longer one and the importance of alkyl groups on the overall DSSC device performance for the unsymmetrical squaraine dyes.

1 aSingh, Amrita1 aSingh, Ambarish, Kumar1 aDixit, Ruchi1 aVanka, Kumar1 aKrishnamoorthy, Kothandam1 aNithyanandhan, Jayaraj uhttps://library.ncl.res.in/content/effect-position-donor-units-and-alkyl-groups-dye-sensitized-solar-cell-device-performance02594nas a2200277 4500008004100000022001400041245017000055210006900225260000900294300001400303490000600317520158800323653002401911653002701935653003201962653001701994653002602011653001902037100001802056700002702074700001702101700001702118700003002135700002702165856012402192 2024 eng d a2574-096200aVisible, far-red, and near-infrared active unsymmetrical squaraine dyes based on extended conjugation within the polymethine framework for dye-sensitized solar cells0 aVisible farred and nearinfrared active unsymmetrical squaraine d cFEB  a1461-14750 v73 a

Alkyl group wrapped visible, far-red, and NIR active unsymmetrical squaraine dyes with pi-extension in the polymethine framework-based AM4-AM7 have been designed, synthesized, and utilized as sensitizers for dye-sensitized solar cells. To extend the pi-conjugation within the polymethine framework, thiophene moieties have been incorporated between the donor and acceptor moieties. Absorption spectroscopic studies revealed that pi-extension with each -C & boxH;C- unit resulted similar to 100 nm of redshift in the charge transfer transition with the lambda(maximum) of 541, 643, 747, and 833 nm for AM4, AM5, AM6, and AM7 dyes, respectively, with the molar extinction coefficient of >10(5) M(-1)cm(-1). The pi-extended conjugation-based AM6 and AM7 dyes showed improved light-harvesting efficiency (LHE), where the AM7 dye showed an LHE of 386 nm at 60%. Electrochemical studies of AM dyes revealed that the HOMO energy level of the sensitizers has been modulated systematically. Further, pi-extension within the polymethine framework showed a dramatic effect on V-OC, J(SC), and device efficiency when move from visible active AM4 to far-red active to NIR active AM7 dyes. The DSSC efficiencies of 7.35, 5.18, 0.08, and 0.053% have been achieved with the I-/I-3(-) electrolyte (Z-50) for the AM4, AM5, AM6, and AM7 dyes, respectively. Further, AM4 dye has been cosensitized with AM5, AM6, and AM7 dyes, where AM4:AM5 (1:1) composition achieved the maximum efficiency of 8.12% with I-/I-3(-) electrolyte (Z-50) compared to the other cosensitization compositions.

10aaggregation of dyes10aDSSC device efficiency10alight-harvesting efficiency10api-extension10apolymethine framework10asquaraine dyes1 aSingh, Amrita1 aSingh, Ambarish, Kumar1 aDixit, Ruchi1 aVanka, Kumar1 aKrishnamoorthy, Kothandam1 aNithyanandhan, Jayaraj uhttps://library.ncl.res.in/content/visible-far-red-and-near-infrared-active-unsymmetrical-squaraine-dyes-based-extended