@article {48051, title = {Tridentate NacNac stabilized tin and nickel complexes: access to a monomeric nickel hydride and its catalytic application}, journal = {Inorganic Chemistry}, volume = {61}, year = {2022}, month = {OCT}, pages = {17370-17377}, type = {Article}, abstract = {

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.

}, issn = {0020-1669}, doi = {10.1021/acs.inorgchem.2c03227}, author = {Pahar, Sanjukta and Sharma, Vishal and Mahata, Biplab and George, Christy P. and Sharma, Himanshu and Vanka, Kumar and Sen, Sakya S.} } @article {48938, title = {Lanthanide mimicking by magnesium for oxazolidinone synthesis}, journal = {Chemistry- a european journal}, volume = {30}, year = {2024}, month = {JAN }, type = {Article}, abstract = {

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

}, keywords = {catalysis, Magnesium, oxazolidinone, pincer ligand, Sustainability}, issn = {0947-6539}, doi = {10.1002/chem.202303478}, author = {Kumar, Rohit and Mahata, Biplab and Gayathridevi, S. and Raj, K. Vipin and Vanka, Kumar and Sen, Sakya S.} } @article {49693, title = {Magnesium-catalyzed primary, secondary, and tertiary amide hydroboration}, journal = {Inorganic Chemistry}, volume = {64}, year = {2025}, month = {JUN}, pages = {13405-13414}, type = {Article}, abstract = {

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.

}, issn = {0020-1669}, doi = {10.1021/acs.inorgchem.5c01787}, author = {Mahata, Biplab and Devaraj, V. and Dash, Soumya Ranjan and Gonnade, Rajesh G. and Vanka, Kumar and Sen, Sakya S.} }