01809nas a2200241 4500008004100000245012900041210006900170260000800239300000900247490000700256520098200263653001101245653003101256653000901287653001901296653001101315100001701326700002101343700003401364700001701398700002301415856012901438 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 uhttp://library.ncl.res.in/content/silver-dependent-enantiodivergent-goldi-catalysed-asymmetric-intramolecular-hydroamination01839nas a2200217 4500008004100000022001400041245012600055210006900181260000800250300001600258490000700274520107300281100002001354700001901374700001901393700002401412700002101436700001701457700001901474856012801493 2022 eng d a0020-166900aTridentate NacNac stabilized tin and nickel complexes: access to a monomeric nickel hydride and its catalytic application0 aTridentate NacNac stabilized tin and nickel complexes access to  cOCT a17370-173770 v613 a

The transmetalation reaction of picolyl-supported tridentate nacnac germylene monochloride [2,6-iPr2-C6H3NC-(Me)CHC(Me)NH(CH2py)]GeCl (1) (py = pyridine) with SnCl2 results in an analogous stannylene chloride (2). The three -coordinated stannylenium cation [{2,6-iPr2-C6H3NC(Me)CHC-(Me)NH(CH2py)}Sn]+ with SnCl3- as a counteranion (3) has been generated through the abstraction of chloride ligand from 2 using an additional equivalent of SnCl2. Instead of forming a donor-acceptor complex, 2 undergoes a facile redox trans-metalation reaction with Ni(COD)2 (COD = cyclooctadiene) and CuCl to afford analogous nickel and copper complexes [2,6-iPr2-C6H3NC(Me)CHC(Me)NH(CH2py)]MCl [M = Ni (4) and Cu (5)]. The reactions of 4 with potassium tri-sec-butylborohydride (commonly known as K-selectride) and AgSbF6 provide access to monomeric Ni(II) hydride, [2,6-iPr2-C6H3NC(Me)CHC(Me)NH(CH2py)]NiH (6) and a Ni(II) cation, [{2,6-iPr2- C6H3NC(Me)CHC(Me)NH(CH2py)}Ni][SbF6] (7), respectively. 6 was found to be an effective catalyst for the hydroboration of amides.

1 aPahar, Sanjukta1 aSharma, Vishal1 aMahata, Biplab1 aGeorge, Christy, P.1 aSharma, Himanshu1 aVanka, Kumar1 aSen, Sakya, S. uhttp://library.ncl.res.in/content/tridentate-nacnac-stabilized-tin-and-nickel-complexes-access-monomeric-nickel-hydride-and01264nas a2200253 4500008004100000022001400041245010900055210006900164260000900233300001500242490000700257520044600264653001200710653002300722653001800745653002400763100001700787700001900804700001800823700002100841700001700862700001900879856011200898 2022 eng d a1867-388000aWell-defined calcium compound catalyzes trimerization of arylisocyanates into 1,3,5-triarylisocyanurates0 aWelldefined calcium compound catalyzes trimerization of arylisoc cJUN  ae2021017880 v143 a

We report the synthesis of a calcium complex (2) bearing a tetradentate monoanionic ligand with a diaminoethane core and phenolate and pyridine peripheral donors. Single crystal X-ray studies on 2 revealed that LiI was also co-crystallized, leading to a four-membered ring with four different elements. 2 was found to be an efficient catalyst for the cyclotrimerization of a variety of aromatic isocyanates under mild conditions.

10acalcium10aCyclotrimerization10aIsocyanurates10aTetradentate ligand1 aKumar, Rohit1 aSharma, Vishal1 aJain, Shailja1 aSharma, Himanshu1 aVanka, Kumar1 aSen, Sakya, S. uhttp://library.ncl.res.in/content/well-defined-calcium-compound-catalyzes-trimerization-arylisocyanates-13501093nas a2200205 4500008004100000022001400041245010400055210006900159260000800228300001400236490000700250520037300257100001900630700002100649700001700670700002600687700002400713700001900737856013100756 2023 eng d a1359-734500aOn the competition between six-membered and five-membered NHC towards alane centered ring expansion0 acompetition between sixmembered and fivemembered NHC towards ala cJUL a8540-85430 v593 a

The combination of 6-SIDipp center dot AlH3 (1) and 5-IDipp resulted in the ring expansion of 6-NHC, while the five-membered NHC remained unchanged, which was subsequently explained by DFT studies. Besides, the substitution chemistry of 1 was also studied with TMSOTf and I-2, which gave rise to the substitution of a hydride by triflate or iodide ligands.

1 aBalayan, Kajal1 aSharma, Himanshu1 aVanka, Kumar1 aRavindranathan, Sapna1 aGonnade, Rajesh, G.1 aSen, Sakya, S. uhttp://library.ncl.res.in/content/competition-between-six-membered-and-five-membered-nhc-towards-alane-centered-ring-expansion02223nas a2200253 4500008004100000022001400041245010100055210006900156260000800225300001100233490000800244520136700252653002401619653003201643653002201675653002901697653002101726653001801747100002101765700001901786700002401805700001701829856012301846 2023 eng d a0022-328X00aComputational insights into the iron-catalyze d magnesium-me diate d hydroformylation of alkynes0 aComputational insights into the ironcatalyze d magnesiumme diate cFEB a1226210 v9863 a

Iron is one of the most abundant transition metals in the earth's crust. It has attracted a lot of attention due to its low toxicity, bio-compatibility, and high natural abundance. Iron-catalyzed hydroamination, hydroalkoxylation, hydrocarboxylation, hydrosilylation, hydroboration, hydrophosphination, hydromagnesiation, and carbonylation reactions have therefore been developed over the past decades. However, despite many experimental and theoretical studies, a complete mechanistic understanding of iron-catalyzed hydrofunctionalisation at the molecular level has not yet been achieved. In this work, through density functional theory (DFT) calculations, we have shown the most feasible path for the hydroformylation of alkynes for an experimentally studied system. We have looked at the iron salt as a precatalyst without any external donor ligand, and the calculations revealed that hydrometalation followed by beta-hydride elimination was favorable over the direct migration of the beta-hydrogen to carbon. Furthermore, our calculations show that the solvent plays an important role in the hydromagnesiation reaction. Furthermore, we have employed an explicit solvent model, where the attachment of one molecule of solvent to the iron center was seen to stabilize the transition states significantly.(c) 2023 Elsevier B.V. All rights reserved.

10aComputational study10aEthylene Assisted Catalysis10aEtMgBr Assistance10aExplicit Role of Solvent10aHydroformylation10aIron Catalyst1 aSharma, Himanshu1 aTewari, Tanuja1 aChikkali, Samir, H.1 aVanka, Kumar uhttp://library.ncl.res.in/content/computational-insights-iron-catalyze-d-magnesium-me-diate-d-hydroformylation-alkynes02778nas a2200217 4500008004100000245010100041210006900142260000900211300001400220490000700234520201600241100002502257700002402282700002102306700002702327700001902354700001702373700001802390700002402408856012802432 2023 eng d00aRivaroxaban eutectics with improved solubility, dissolution rates, bioavailability and stability0 aRivaroxaban eutectics with improved solubility dissolution rates cJUN  a3253-32630 v253 a

Rivaroxaban (RXB) is a direct factor Xa inhibitor used for the treatment of deep vein thrombosis (DVT, a blood clot in the leg) and pulmonary embolism (PE, a blood clot in the lung) and to prevent blood clots in atrial fibrillation following hip or knee surgery. However, RXB suffers from poor solubility that hinders its broader application. Although its cocrystals are reported for solubility enhancement, the methodology used to prepare multi-component crystals is complex. Also, it uses hazardous solvents to develop cocrystals. We have prepared eutectics of RXB with caffeic acid (CAA), coumaric acid (CA), fumaric acid (FA), succinic acid (SA), mandelic acid (MA) and trimesic acid (TA) and analyzed them using hot stage microscopy (HSM), differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD), and fourier transform infrared spectroscopy (FTIR) techniques. The saturation solubility and dissolution rate profiles were also obtained to investigate the effect of eutectics on these parameters. Amongst all the coformers tested, coformers CAA, CA, and FA showed significant enhancement in the solubility of RXB. The powder dissolution rate of the eutectics showed considerable enhancement compared to that of RXB. In vivo pharmacokinetic study was carried out for RXB-CAA, RXB-CA and RXB-FA in rats and compared with RXB, which showed 1.5 and 1.4 times enhancement in relative bioavailability for RXB-CAA and RXB-CA, respectively. Stability studies were carried out as per ICH guidelines for all the eutectics, which revealed excellent stability over six months under accelerated (40 degrees C and 75%) conditions and twelve months under long-term (30 degrees C and 60% RH) conditions. The DFT studies carried out using the B3LYP/TZVP level of theory revealed higher Gibbs free interaction energy (Delta G(int)) for homosynthons (drugMIDLINE HORIZONTAL ELLIPSISdrug and coformerMIDLINE HORIZONTAL ELLIPSIScoformer) than heterosynthons (drugMIDLINE HORIZONTAL ELLIPSIScoformer).

1 aShaligram, Parth, S.1 aGeorge, Christy, P.1 aSharma, Himanshu1 aMahadik, Kakasaheb, R.1 aPatil, Sharvil1 aVanka, Kumar1 aArulmozhi, S.1 aGonnade, Rajesh, G. uhttp://library.ncl.res.in/content/rivaroxaban-eutectics-improved-solubility-dissolution-rates-bioavailability-and-stability