01464nas a2200217 4500008004100000022001400041245021200055210006900267260007400336300001200410490000700422520055700429100001700986700002001003700001501023700002201038700001601060700002501076700002401101856012101125 2005 eng d a0340-428500aMetalloantitubercular compounds part 3: synthesis, crystal structure, spectroscopy, electrochemistry and antimycobacterial activity of the copper(II) ciproploxacin (cfH) complex and its phenanthroline adduct0 aMetalloantitubercular compounds part 3 synthesis crystal structu aVAN GODEWIJCKSTRAAT 30, 3311 GZ DORDRECHT, NETHERLANDSbSPRINGERcAPR a334-3400 v303 a

The X-ray crystal structures of two ciprofloxacin compounds, viz. [Cu(cfH)(2)(Cl)(2)] (.) 2MeOH (.) 6H2O (2) and [Cu(cfH)(phen)Cl]BF4 (.) 4H(2)O (3) are reported. Complex ( 2) has a distorted octahedral geometry, whereas for the nitrogen adduct (3) a distorted square-pyramidal geometry is seen. Significant enhancement in the antimycobacterial activity of the copper conjugates correlates with their copper redox couples (Cu2+/Cu+) probably due to its relevance to intracellular accumulations and subsequent role in generating oxidative stress.

1 aSaha, D., K.1 aPatitungkho, S.1 aPadhye, S.1 aDeobagkar, D., N.1 aOzarkar, A.1 aBhadbhade, Mohan, M.1 aGonnade, Rajesh, G. uhttps://library.ncl.res.in/content/metalloantitubercular-compounds-part-3-synthesis-crystal-structure-spectroscopy-101764nas a2200241 4500008004100000022001400041245014500055210006900200260007300269300001200342490000800354520083600362653002101198653001601219653002201235653002001257100002401277700002101301700002401322700002201346700002501368856012901393 2008 eng d a0022-286000aMolecular association via halogen bonding and other weak interactions in the crystal structures of 11-bromo-12-oxo-5 beta-cholan derivatives0 aMolecular association via halogen bonding and other weak interac aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcDEC a246-2530 v8923 a

Methyl 3 alpha,7 alpha-diacetoxy-12-oxo-5 beta-cholan-24-oate 2, methyl 11 alpha-bromo-3 alpha,7 alpha-diacetoxy-12-oxo-5 beta-cholan-24-oate 3, methyl 11 beta-bromo-3 alpha,7 alpha-diacetoxy-12-oxo-5 beta-cholan-24-oate 4 and methyl 11,11-dibromo-3 alpha,7 alpha-diacetoxy-12-oxo-5 beta-cholan-24-oate 5 were synthesized. The crystal structures of these molecules were resolved to study the effect of bulky bromine atom in the steroid skeleton of cholic acid with different stereo-chemical orientations at C-11 on the two-dimensional arrangement of molecules and solid-state properties. All the molecules associate only via weak intermolecular interactions in their crystal structures, notable one being the Halogen Bonded assembly (C-Br center dot center dot center dot O) in 5. (C) 2008 Elsevier B.V. All rights reserved.

10a11-Bromosteroids10aCholic acid10acrystal structure10aHalogen bonding1 aSalunke, Deepak, B.1 aHazra, Braja, G.1 aGonnade, Rajesh, G.1 aPore, Vandana, S.1 aBhadbhade, Mohan, M. uhttps://library.ncl.res.in/content/molecular-association-halogen-bonding-and-other-weak-interactions-crystal-structures-11-002289nas a2200265 4500008004100000022001400041245013500055210006900190260007300259300001200332490000800344520125900352653001801611653003201629653004501661653003001706653001501736653002201751100002401773700002801797700002401825700002101849700002201870856013101892 2009 eng d a0022-286000aMagnetic phase transition in valence tautomers as polymorphs of 3-iodolawsone: Single crystal X-ray structure, DSC and EPR studies0 aMagnetic phase transition in valence tautomers as polymorphs of  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcDEC a328-3350 v9383 a

Three polymorphs of 3-iodolawsone (I-III) have been isolated and characterized by single crystal X-ray diffraction, electron paramagnetic resonance (EPR) spectroscopy and differential scanning calorimetry (DSC) techniques. Polymorphs I and II were crystallized from methanol in two different valence tautomeric forms: hydroxynaphthoquinone (HNQ) and hydroxynaphthoseimquinone (HNSQ) as needles and thick plates, respectively. Polymorph III was crystallized from ethanol in HNQ form, as thin plates Chiral crystals of I belongs to the orthorhombic P2(1)2(1)2(1) space group: II and III belong to the monochnic non-centrosymmetric space group Cc. The molecules are packed via O-H O bonding and pi . pi stacking interactions. The study reveals that relatively stronger intermolecular H-bonding (2.02 angstrom) and most favoured pi . pi stacking (similar to 3 49 angstrom) interactions lead II to HNSQ radicals, presence of which was confirmed by EPR (g = 2.0052) spectroscopy. Interestingly, these materials exhibit crystal-to-crystal magnetic phase transition from polymorph I (diamagnetic) to polymorph II (paramagnetic structure) at 171.1 degrees C as identified by DSC and X-ray crystallographic studies (C) 2009 Elsevier B.V. All rights reserved

10a3-Iodolawsone10aHydroxynaphthoquinone (HNQ)10aHydroxynaphthosemiquinone radical (HNSQ)10aMagnetic phase transition10aPolymorphs10aValence tautomers1 aZaware, Santosh, B.1 aDagade-Waghmode, Shobha1 aGonnade, Rajesh, G.1 aSrinivas, Darbha1 aRane, Sandhya, Y. uhttps://library.ncl.res.in/content/magnetic-phase-transition-valence-tautomers-polymorphs-3-iodolawsone-single-crystal-x-ray-001283nas a2200205 4500008004100000022001400041245007400055210006900129260011000198300001600308490000700324520048900331100002500820700001700845700002200862700002400884700003500908700002800943856010600971 2012 eng d a1359-734500aMultifaceted folding in a foldamer featuring highly cooperative folds0 aMultifaceted folding in a foldamer featuring highly cooperative  aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcSEP a11205-112070 v483 a

Herein, we report on the folding pattern observed in a synthetic peptide featuring two highly mutually dependent, yet strikingly dissimilar, closed networks of hydrogen-bonded rings that work in a cumulative fashion to stabilize the entire folded architecture of the peptide. Structural studies unequivocally suggest that disruption of any one of these mutually-dependent hydrogen-bonded networks is deleterious to the stability of the fully folded conformation of the peptide.

1 aRamesh, Veera, V. E.1 aPriya, Gowri1 aKotmale, Amol, S.1 aGonnade, Rajesh, G.1 aRajamohanan, Pattuparambil, R.1 aSanjayan, Gangadhar, J. uhttps://library.ncl.res.in/content/multifaceted-folding-foldamer-featuring-highly-cooperative-folds-001071nas a2200181 4500008004100000022001400041245007300055210006900128260007100197300001400268490000700282520040800289100001700697700002100714700002400735700002200759856010800781 2013 eng d a1523-706000aMulticomponent reactions involving arynes, quinolines, and aldehydes0 aMulticomponent reactions involving arynes quinolines and aldehyd a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcSEP a4620-46230 v153 a

The multicomponent reaction involving arynes, quinolines, and aldehydes leading to the diastereoselective synthesis of benzoxazino quinoline derivatives in good yields proceeding via 1,4-zwitterionic intermediates is reported. In addition, the synthetic potential of various carbonyl compounds in this reaction as well as the utility of isoquinoline as the nucleophilic trigger has been examined.

1 aBhunia, Anup1 aPorwal, Digvijay1 aGonnade, Rajesh, G.1 aBiju, Akkattu, T. uhttps://library.ncl.res.in/content/multicomponent-reactions-involving-arynes-quinolines-and-aldehydes-001426nas a2200193 4500008004100000022001400041245007200055210006900127260011000196300001600306490000700322520068800329100001701017700002301034700002101057700002401078700002201102856010801124 2014 eng d a1359-734500aMulticomponent reactions involving phosphines, arynes and aldehydes0 aMulticomponent reactions involving phosphines arynes and aldehyd aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcAUG a11389-113920 v503 a

Although nucleophilic phosphine-catalysis is a powerful tool for the construction of various carbocycles and heterocycles, the reactions in which phosphines are incorporated into the final product are rare, and the reports on phosphine addition to highly electrophilic arynes are scarce. Herein, we report the phosphine triggered multicomponent reaction of arynes and aldehydes, which takes place via the formal [3+2] cycloaddition of an initially generated 1,3-phosphonium zwitterion from phosphines and arynes with aldehydes. The reaction resulted in the formation of a diverse range of stable pentacovalent phosphoranes in good yields based on the benzooxaphosphole system.

1 aBhunia, Anup1 aKaicharla, Trinadh1 aPorwal, Digvijay1 aGonnade, Rajesh, G.1 aBiju, Akkattu, T. uhttps://library.ncl.res.in/content/multicomponent-reactions-involving-phosphines-arynes-and-aldehydes-000966nas a2200181 4500008004100000022001400041245016300055210006900218260011000287300001600397490000600413520014400419100002200563700002400585700002400609700002000633856013100653 2015 eng d a2046-206900aMono- and binuclear palladacycles via regioselective C-H bond activation: syntheses, mechanistic insights and catalytic activity in direct arylation of azoles0 aMono and binuclear palladacycles via regioselective CH bond acti aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcSEP a81502-815140 v53 a

{Regioselective C-H bond palladation of the hybrid pincer-type ligands, 3-R2PO-C6H4-1-(CH2NPr2)-Pr-i [(POCNiPr2)-P-R2-H; R = Ph (1a)

1 aPandey, Dilip, K.1 aKhake, Shrikant, M.1 aGonnade, Rajesh, G.1 aPunji, Benudhar uhttps://library.ncl.res.in/content/mono-and-binuclear-palladacycles-regioselective-c-h-bond-activation-syntheses-mechanistic-002017nas a2200193 4500008004100000245014400041210006900185260000800254300001400262490000700276520128500283100002401568700002201592700002301614700002401637700001701661700002001678856012501698 2016 eng d00aMechanistic insights into pincer-ligated palladium-catalyzed arylation of azoles with aryl Iodides: evidence of a Pd-II-Pd-IV-Pd-II pathway0 aMechanistic insights into pincerligated palladiumcatalyzed aryla cMAR a875–8860 v353 a

Pincer-based (R2POCNR′2)PdCl complexes along with CuI cocatalyst catalyze the arylation of azoles with aryl iodides to give the 2-arylated azole products. Herein, we report an extensive mechanistic investigation for the direct arylation of azoles involving a well-defined and highly efficient (iPr2POCNEt2)PdCl (2a) catalyst, which emphasizes a rare PdII–PdIV–PdII redox catalytic pathway. Kinetic studies and deuterium labeling experiments indicate that the C–H bond cleavage on azoles occurs via two distinct routes in a reversible manner. Controlled reactivity of the catalyst 2a underlines the iodo derivative (iPr2POCNEt2)PdI (3a) to be the resting state of the catalyst. The intermediate species (iPr2POCNEt2)Pd-benzothiazolyl (4a) has been isolated and structurally characterized. A determination of reaction rates of compound 4a with electronically different aryl iodides has revealed the kinetic significance of the oxidative addition of the C(sp2)–X electrophile, aryl iodide, to complex 4a. Furthermore, the reactivity behavior of 4a suggests that the arylation of benzothiazole proceeds via an oxidative addition/reductive elimination pathway involving a (iPr2POCNEt2)PdIV(benzothiazolyl)(Ar)I species, which is strongly supported by DFT calculations.

1 aKhake, Shrikant, M.1 aJagtap, Rahul, A.1 aDangat, Yuvraj, B.1 aGonnade, Rajesh, G.1 aVanka, Kumar1 aPunji, Benudhar uhttps://library.ncl.res.in/content/mechanistic-insights-pincer-ligated-palladium-catalyzed-arylation-azoles-aryl-iodides01771nas a2200181 4500008004100000245011100041210006900152260000800221300001600229490000700245520108800252100002301340700002001363700002301383700002401406700002801430856013101458 2017 eng d00aModular approach towards functionalized highly stable self-complementary quadruple hydrogen bonded systems0 aModular approach towards functionalized highly stable selfcomple cDEC a10087-100940 v153 aSelf-complementary quadruple hydrogen bonded systems have shown potential as key building blocks for developing various supramolecular polymers. Opportunities for the introduction of multiple functionalities would further augment, in principle, their application potential. Herein, we report a novel modular approach to simultaneously introduce two closely aligned side chains into AADD-type self-complementary quadruple hydrogen-bonding systems. Dithiane-tethered ureidopyrimidinone has been used as a reactive intermediate to efficiently attach closely aligned side chains by simply reacting with amines to form highly stable molecular duplexes. These duplexes featuring AADD-type arrays of hydrogen bonding codes are highly stable in non-polar solvents (K-dim > 1.9 x 10(7) M-1 in CDCl3) as well as in polar solvents (K-dim > 10(5) in 10% DMSO-d(6)/CDCl3). Another notable feature of these self-assembling systems is their insensitivity to prototropy-related issues owing to their prototropic degeneracy, which will enhance their application potential in supramolecular chemistry.1 aRayavarapu, Suresh1 aKheria, Sanjeev1 aShinde, Dinesh, R.1 aGonnade, Rajesh, G.1 aSanjayan, Gangadhar, J. uhttps://library.ncl.res.in/content/modular-approach-towards-functionalized-highly-stable-self-complementary-quadruple-hydrogen02240nas a2200205 4500008004100000022001400041245009000055210006900145260000800214300001400222490000700236520155700243100002401800700001801824700002101842700002401863700001701887700002001904856011001924 2018 eng d a0276-733300aMechanism of nickel(II)-catalyzed C(2)-H alkynylation of indoles with alkynyl bromide0 aMechanism of nickelIIcatalyzed C2H alkynylation of indoles with  cJUL a2037-20450 v373 a

The nickel system (THF)(2)NiBr2/phen has recently been shown as an efficient catalyst for the C-H bond alkynylation of diverse heteroarenes with (triisopropylsilyl)alkynyl bromide via monodentate chelation assistance. Herein, we report an extensive mechanistic investigation for the direct alkynylation of indoles involving the well-defined nickel catalyst, which features a coordinative insertion pathway of alkynyl bromide with the Ni(II) catalyst. Catalytic relevant nickel complexes, (phen)NiCl2 (5), (phen)(2)NiCl2 (6) and [(phen)(3)Ni].NiCl4 (7) were isolated, and the complexes 6 and 7 were structurally characterized. Well-defined complexes were as competent as the in situ generated catalyst system (THF)(2)NiBr2/phen for the alkynylation of indoles. Various controlled studies and reactivity experiments were performed to understand the probable pathway for the alkynylation reaction. Kinetics analysis highlights that the complex (phen)NiX2 acts as a precatalyst, and the involvement of substrate indole and LiO'Bu are essential for the generation of the active catalyst. Deuterium labeling and kinetic studies suggest that the process involving C-H cleavage and carbo-nickelation of indole is a crucial rate influencing step. Reactivity study of various alkynyl compounds with nickel-species highlights a migratory insertion route for the reaction. DFT calculations firmly support the experimental findings and suggest the coordinative insertion pathway of alkynyl bromide rather than oxidative addition toward the nickel(II) center.

1 aKhake, Shrikant, M.1 aJain, Shailja1 aPatel, Ulhas, N.1 aGonnade, Rajesh, G.1 aVanka, Kumar1 aPunji, Benudhar uhttps://library.ncl.res.in/content/mechanism-nickelii-catalyzed-c2-h-alkynylation-indoles-alkynyl-bromide02045nas a2200205 4500008004100000022001400041245010400055210006900159260000800228300001400236490000700250520133400257100002101591700001801612700002201630700002401652700001701676700002001693856012601713 2018 eng d a0276-733300aMechanistic aspects of pincer nickel(II)-catalyzed C-H bond alkylation of azoles with alkyl halides0 aMechanistic aspects of pincer nickelIIcatalyzed CH bond alkylati cMAR a1017-10250 v373 a

The quinolinyl-based pincer nickel complex, kappa(N),kappa(N),kappa(N)-{C9H6N-(mu-N)-C6H4-NMe2}NiCl [((NNNMe2)-N-Q)-NiCl; (1)] has recently been demonstrated to be an efficient and robust catalyst for the alkylation of azoles with alkyl halides under copper-free conditions. Herein, we report the detailed mechanistic investigation for the alkylation of azoles catalyzed by ((NNNMe2)-N-Q)NiCl (1), which highlights an iodine atom transfer (IAT) mechanism for the reaction involving a Ni-II/Ni-III process. Deuterium labeling experiments indicate reversible cleavage of the benzothiazole C-H bond, and kinetic studies underline a fractional negative rate order with the substrate benzothiazole. The involvement of an alkyl radical during the alkylation is validated by radical clock and external additive experiments. An active intermediate species ((NNNMe2)-N-Q)Ni(benzothiazolyl) (5a) has been isolated and structurally characterized. The complex ((NNNMe2)-N-Q)Ni(benzothiazoly1) (5a) is found to be the resting state of catalyst 1. Kinetic analysis of electronically different intermediates suggests that the step involving the reaction of 5a with alkyl iodide is crucial and a rate-influencing step. DFT calculations strongly support the experimental findings and corroborate an IAT process for the alkylation reaction.

1 aPatel, Ulhas, N.1 aJain, Shailja1 aPandey, Dilip, K.1 aGonnade, Rajesh, G.1 aVanka, Kumar1 aPunji, Benudhar uhttps://library.ncl.res.in/content/mechanistic-aspects-pincer-nickelii-catalyzed-c-h-bond-alkylation-azoles-alkyl-halides02548nas a2200229 4500008004100000022001400041245016300055210006900218260000900287300001200296490000600308520169200314100001902006700003102025700002402056700001702080700002002097700002702117700002402144700002002168856013002188 2021 eng d a2050-752600aMetal halide structure and the extent of distortion control the photo-physical properties of luminescent zero dimensional organic-antimony(iii) halide hybrids0 aMetal halide structure and the extent of distortion control the  cJAN  a348-3580 v93 a

Antimony(iii) halide based zero dimensional hybrids have gained attention as broadband emitters. Until now, quadrangular pyramidal SbX5 based and octahedral SbX6 based 0D hybrids have been reported utilizing different organic ligands demonstrating some structural tunability affecting their emissive properties. Utilizing a common organic ligand, here we demonstrate the structural tunability (quadrangular pyramidal, octahedral, or a combination thereof) of the metal halide unit in Sb(iii)Cl 0D hybrids with contrasting photo-physical properties (broadband, Stokes shift, strong/weak colored emission). The structure-property-mechanism correlation of the synthesized compounds [1 (C12H52Cl18N8O4Sb3; tris Sb green); 2 (C12H50Cl14N8O3Sb2; tris Sb red); 3 (C24H88Cl25N16O4Sb3; tris Sb yellow)] identifies crucial factors that control their emissive properties. The X-ray analysis reveals the structure (1-octahedral; 2-quadrangular pyramidal; 3-combination thereof) and the order of the extent of structural distortion as 1-3 MUCH LESS-THAN 2. The metal halide coordination environment asymmetry and its structure are observed to dictate PL emission energy (1-green; 2-red; 3-yellow) as supported by a qualitative Molecular Orbital scheme. The extent of structural distortion guides the observed Stokes shifts (1-165 nm; 2-290 nm; 3-200 nm; 1-3 < 2). Interestingly, the extent of distortion is found to be well correlated with the observed PLQY (1-45%; 2-6%; 3-43%; 1-3 >> 2). This report clearly demonstrates the structural tunability and the effect of the metal halide unit structure/distortion in shaping the emissive properties of 0D organic Sb(iii) halide hybrids.

1 aBiswas, Anupam1 aBakthavatsalam, Rangarajan1 aMali, Bhupendra, P.1 aBahadur, Vir1 aBiswas, Chinmoy1 aRaavi, Sai, Santosh Ku1 aGonnade, Rajesh, G.1 aKundu, Janardan uhttps://library.ncl.res.in/content/metal-halide-structure-and-extent-distortion-control-photo-physical-properties-luminescent01579nas a2200265 4500008004100000022001400041245006600055210006600121260000900187490000700196520078400203653001400987653001401001653002401015653001601039653002001055100001701075700001701092700001901109700002201128700002401150700001901174700001901193856010101212 2022 eng d a0947-653900aMonomeric magnesium catalyzed alkene and alkyne hydroboration0 aMonomeric magnesium catalyzed alkene and alkyne hydroboration cOCT 0 v283 a

In this work, two monomeric magnesium alkyl complexes (1 and 2) were prepared using bis(phosphino)carbazole framework and among them 1 has been used as a catalyst for hydroboration of alkenes and alkynes with pinacolborane (HBpin). A broad variety of aromatic and aliphatic alkenes and alkynes were efficiently reduced. Anti-Markovnikov regioselective hydroboration of alkenes and alkynes was achieved, which was confirmed by deuterium-labelling experiments. The work represents the first example of the use of magnesium in homogeneous catalytic hydroboration of alkene with broad substrate scope. Experimental mechanistic investigations and DFT calculations provided insights into the reaction mechanism. Finally, the hydroboration protocol was extended to terpenes.

10acarbazole10aMagnesium10amonomeric complexes10aphosphorous10aX-ray Structure1 aKumar, Rohit1 aDutta, Sayan1 aSharma, Vishal1 aSingh, Praval, P.1 aGonnade, Rajesh, G.1 aKoley, Debasis1 aSen, Sakya, S. uhttps://library.ncl.res.in/content/monomeric-magnesium-catalyzed-alkene-and-alkyne-hydroboration01801nas a2200253 4500008004100000022001400041245012100055210007100176260000800247300001400255490000800269520091600277653001001193653002301203653002101226653002501247653001401272653002901286100002301315700002101338700002401359700002001383856014401403 2024 eng d a1615-415000aManganese-catalyzed chemoselective direct hydrogenation of α,β-epoxy ketones and α-ketoamides at room temperature0 aManganesecatalyzed chemoselective direct hydrogenation of αβepox cAUG a3338-33450 v3663 a

Chemoselective hydrogenation of alpha,beta-epoxy ketones and alpha-ketoamides is achieved at room temperature (25 degrees C) using 2.0 bar H-2 and a pincer-ligated Mn(I) catalyst that provides synthetically valuable alpha-hydroxy epoxides and alpha-hydroxy amides. This protocol applies to a wide range of alkyl- and aryl-substituted alpha,beta-epoxy ketones, including terpenes (alpha-ionone, nootkatone, and R-carvone)- and steroids (testosterone and progesterone)-derived epoxy ketones, and tolerates H-2 sensitive functionalities, such as halides, acetyl, nitrile, nitro, epoxide, alkenyl and alkynyl groups. Additionally, alpha-ketoamides bearing reducible functional groups, including acetyl and diazo benzene, were untouched under this protocol and selectively converted to alpha-hydroxy amides. A preliminary mechanistic study highlighted the metal-ligand cooperative H-2 activation process.

10aalpha10abeta-epoxy ketones10achemoselectivity10adirect hydrogenation10amanganese10aMetal-ligand cooperation1 aShabade, Anand, B.1 aSingh, Rahul, K.1 aGonnade, Rajesh, G.1 aPunji, Benudhar uhttps://library.ncl.res.in/content/manganese-catalyzed-chemoselective-direct-hydrogenation-%CE%B1%CE%B2-epoxy-ketones-and-%CE%B1-ketoamides01936nas a2200241 4500008004100000022001400041245014800055210006900203260000800272490000700280520105400287653003201341653003001373653002501403653001201428653001501440100002101455700001901476700002101495700002401516700002801540856012601568 2024 eng d a2193-580700aMethanesulfonic acid-catalyzed friedel-crafts alkylation: towards sustainable synthesis of arylalkanes from donor-acceptor cyclopropane ketones0 aMethanesulfonic acidcatalyzed friedelcrafts alkylation towards s cJUL0 v133 a

We present herein Br & oslash;nsted acid-catalyzed Friedel-Crafts alkylation of phenols with Donor-Acceptor cyclopropane ketones. The presence of the 1,4-diphenyl butan-1-one and 1,3-diphenyl propane-1-one motifs in various naturally occurring biologically significant molecules inspired us to pursue the direct synthesis of these structural frameworks. Utilizing methanesulfonic acid (MeSO3H) as a catalyst, we achieved a more environmentally friendly and high-yielding synthesis, owing to its cost-effectiveness, biodegradability, transition-metal and additives free conditions. Furthermore, we have successfully extended our developed methodology to thiophenols, resulting in the production of sulfur-based butan-1-one derivatives in good yields. The presence of 1,4-diphenyl butan-1-one and 1,3-diphenyl propane-1-one motifs in various naturally occurring biologically significant molecules prompted us to develop a Br & oslash;nsted acid-catalyzed Friedel-Crafts alkylation of phenols with Donor-Acceptor cyclopropane. image

10adonor-acceptor cyclopropane10aFriedel-Crafts alkylation10amethanesulfonic acid10aPhenols10athiophenol1 aGoswami, Lakshmi1 aPaul, Sayantan1 aMamale, Ajay, G.1 aGonnade, Rajesh, G.1 aBhattacharya, Asish, K. uhttps://library.ncl.res.in/content/methanesulfonic-acid-catalyzed-friedel-crafts-alkylation-towards-sustainable-synthesis01621nas a2200205 4500008004100000022001400041245007700055210006900132260000800201300001600209490000700225520095300232100001901185700001601204700002501220700002401245700001701269700001901286856011001305 2025 eng d a0020-166900aMagnesium-catalyzed primary, secondary, and tertiary amide hydroboration0 aMagnesiumcatalyzed primary secondary and tertiary amide hydrobor cJUN a13405-134140 v643 a

Catalytic hydroboration of amides is highly important because the resultant amines are commonly found in natural products, pharmaceuticals, agrochemicals, dyes, and other applications. In comparison to the conventional reduction of amides using (over)stoichiometric reductants, hydroboration of amides using magnesium compounds represents a green and sustainable approach because magnesium is both Earth abundant and environmentally benign. However, there is only one report on magnesium-catalyzed deoxygenative hydroboration of secondary and tertiary amides. Here, we describe the synthesis and structural authentication of two new magnesium compounds (1 and 2) featuring a flexible PNP ligand and the utilization of 2 as a catalyst for the pinacolborane-mediated reduction of primary, secondary, and tertiary amides to amines. The reaction scope is explored, and a mechanism is proposed based on experimental and theoretical insights.

1 aMahata, Biplab1 aDevaraj, V.1 aDash, Soumya, Ranjan1 aGonnade, Rajesh, G.1 aVanka, Kumar1 aSen, Sakya, S. uhttps://library.ncl.res.in/content/magnesium-catalyzed-primary-secondary-and-tertiary-amide-hydroboration02003nas a2200193 4500008004100000022001400041245009200055210006900147260000800216300001200224490000700236520134500243100001901588700002501607700001701632700002401649700001901673856011701692 2025 eng d a0276-733300aMagnesium-ligand cooperation in breaking the O-H and C-H bonds of water and diazoalkane0 aMagnesiumligand cooperation in breaking the OH and CH bonds of w cMAR a875-8810 v443 a

In our previous paper, we reported that the reaction of a tridentate nacnac ligand with a pendant picolyl group, with KHMDS and MgI2, resulted in the formation of a homoleptic hexacoordinate magnesium compound. Here, we show that the analogous reaction of the ligand with CH3MgBr led to a heteroleptic magnesium bromide species (1). Attempts to generate the magnesium hydride species from 1 led to the dearomatization of the pyridine ring, and the resulting product was a magnesium hydroxide (3) presumably generated due to an adventitious amount of water. The reaction of the ligand with nBu2Mg afforded a unique dearomatized magnesium species (2) in high yield. Theoretical calculations reveal the presence of a nonbonding orbital on the magnesium, susceptible to nucleophilic attack. Indeed, the reaction of 2 with H2O/D2O cleaves the O-H/D bond via magnesium-ligand cooperation and generates a magnesium hydroxide (4 and 5). In addition, 2 reacts with Me3SiCHN2 and cleaves the C-H bond to generate another unusual, well-defined magnesium compound with a bridging isocyanide moiety (6) via migration of the SiMe3 group from the carbon to the nitrogen atom. The latter can be described as a dimer of magnesium isocyanamide. DFT calculations were performed to understand the electronic structures of the synthesized molecules.

1 aSharma, Vishal1 aDash, Soumya, Ranjan1 aVanka, Kumar1 aGonnade, Rajesh, G.1 aSen, Sakya, S. uhttps://library.ncl.res.in/content/magnesium-ligand-cooperation-breaking-o-h-and-c-h-bonds-water-and-diazoalkane