01840nas a2200217 4500008004100000022001400041245012600055210006900181260000800250300001600258490000700274520107300281100002001354700001901374700001901393700002401412700002101436700001701457700001901474856012901493 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. uhttps://library.ncl.res.in/content/tridentate-nacnac-stabilized-tin-and-nickel-complexes-access-monomeric-nickel-hydride-and02041nas a2200253 4500008004100000022001400041245006600055210006600121260000900187490000700196520129900203653001401502653001401516653001801530653001801548653001901566100001701585700001901602700002101621700001501642700001701657700001901674856009401693 2024 eng d a0947-653900aLanthanide mimicking by magnesium for oxazolidinone synthesis0 aLanthanide mimicking by magnesium for oxazolidinone synthesis cJAN 0 v303 a

In the last decade, magnesium complexes have emerged as a viable alternative to transition-metal catalysts for the hydrofunctionalization of unsaturated bonds. However, their potential for advanced catalytic reactions has not been thoroughly investigated. To address this gap, we have developed a novel magnesium amide compound (3) using a PNP framework that is both bulky and flexible. Our research demonstrates that compound 3 can effectively catalyze the synthesis of biologically significant oxazolidinone derivatives. This synthesis involves a tandem reaction of hydroalkoxylation and cyclohydroamination of isocyanate using propargyl alcohol. Furthermore, we conducted comprehensive theoretical calculations to gain insights into the reaction mechanism. It is important to note that these types of transformations have not been reported for magnesium and would significantly enhance the catalytic portfolio of the 7th most abundant element. A monomeric magnesium compound was employed as a catalyst for the cascade cyclization of propargylic alcohol and isocyanate, resulting in the formation of pharmaceutically significant oxazolidinone derivatives. This transformation, previously attributed solely to transition metals or lanthanides, signifies a noteworthy advancement.image

10acatalysis10aMagnesium10aoxazolidinone10apincer ligand10aSustainability1 aKumar, Rohit1 aMahata, Biplab1 aGayathridevi, S.1 aRaj, Vipin1 aVanka, Kumar1 aSen, Sakya, S. uhttps://library.ncl.res.in/content/lanthanide-mimicking-magnesium-oxazolidinone-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-hydroboration02040nas a2200181 4500008004100000022001400041245011200055210006900167260000900236300001400245490000700259520138800266100001901654700002001673700001901693700001901712856012701731 2026 eng d a0020-166900aMagnesium-catalyzed CO2 reduction to formic acid or methanol: solvent or no solvent settles the selectivity0 aMagnesiumcatalyzed CO2 reduction to formic acid or methanol solv cAPR  a8793-88030 v653 a

Reducing the carbonyl (C=O) group in carbon dioxide is a difficult yet crucial step for producing valuable chemical compounds. This approach holds promise for creating new methods to utilize nonfossil-based raw materials. Using catalysts made from abundant, inexpensive, and environmentally friendly metals, such as magnesium, could significantly advance the development of sustainable synthetic techniques. In this study, a magnesium pincer compound (1) is shown to facilitate the reduction of CO2 with pinacolborane as the reductant. When used without a solvent, the reaction produces methoxyborane, whereas in THF, it leads to formoxyborane. Formoxyborane has been identified as a ``missing link'' in homogeneous CO2 reduction by catalysts based on alkaline earth metal elements. The variation in product selectivity was substantiated through DFT calculations. The initial generation of the Mg(II) hydride catalyst both in the absence and presence of THF entails an activation barrier within 25-26 kcal mol-1. However, the rate-determining step, in the absence of a solvent, involves hydride transfer-mediated reduction at the formate fragment accompanying a transition barrier of 27.3 kcal mol-1. In the presence of THF, the rate-determining step involves hydride transfer to the Mg center with a barrier of 29.2 kcal mol-1, generating the catalyst and boryl formate.

1 aMahata, Biplab1 aKhilari, Nripen1 aKoley, Debasis1 aSen, Sakya, S. uhttps://library.ncl.res.in/content/magnesium-catalyzed-co2-reduction-formic-acid-or-methanol-solvent-or-no-solvent-settles