01429nas a2200289 4500008004100000022001400041245008100055210006300136260000800199490000700207520052100214653002200735653001300757653003100770653001700801653001200818653002800830653002300858653002600881653002500907653002900932100002600961700002000987700001501007700001901022856009801041 2017 eng d a1359-734500aC(sp(3))-F, C(sp(2))-F and C(sp(3))-H bond activation at silicon(II) centers0 aCsp3F Csp2F and Csp3H bond activation at siliconII centers cSEP0 v533 a

Silylene [PhC(NtBu)(2)SiN(SiMe3)(2)] (1) cleaves the C(sp(3))-H and C-F bonds of acetophenone and 1,1,1-trifluoroacetophenone, respectively, under mild conditions. The reaction is initiated via a nucleophilic attack from the oxygen to the silicon atom followed by C-F/H bond cleavage. The scope of C-F bond activation has further been extended with C6F6 and C6F5CF3.

10aBoron triple bond10aC-F Bond10aFluorinated Building-Block10aH Activation10aKetones10aN-heterocyclic carbenes10aOxodative Addition10aPerfluorinated Arenes10aSelective Activation10aTransition-Metal Centers1 aSwamy, V., S. V. S. N1 aParvin, Nasrina1 aRaj, Vipin1 aSen, Sakya, S. uhttps://library.ncl.res.in/content/csp3-f-csp2-f-and-csp3-h-bond-activation-siliconii-centers00905nas a2200121 4500008004100000245006400041210006400105260000800169520046900177100001500646700001700661856010500678 2017 eng d00aUnderstanding Ziegler–Natta catalysis through your laptop0 aUnderstanding Ziegler–Natta catalysis through your laptop cNOV3 aThis article focuses on the different components that make up Ziegler–Natta olefin polymerization systems and shows how investigating the interactions between these components through computational approaches provide crucial information about the chemistry of these systems. Hence, the necessity of theory acting as a counterpoint to experiment is revealed, underlining the importance of computational chemistry in attacking important problems of the day.1 aRaj, Vipin1 aKumar, Vanka uhttps://library.ncl.res.in/content/understanding-ziegler%E2%80%93natta-catalysis-through-your-laptop01769nas a2200193 4500008004100000245006200041210005600103260000800159300001400167490000700181520119000188100002001378700001901398700001801417700001501435700001701450700001901467856008901486 2018 eng d00aAccess to silicon(II)- and germanium(II)-indium compounds0 aAccess to siliconII and germaniumIIindium compounds cAPR a1206-12130 v373 aDespite the remarkable ability of N-heterocyclic silylene to act as a Lewis base and form stable Lewis adducts with group 13 elements such as boron, aluminum, and gallium, there has been no such comparable investigation with indium and the realization of a stable silylene-indium complex has still remained elusive. Similarly, a germylene-indium complex is also presently unknown. We describe herein the reactions of [PhC(NtBu)(2)SiN-(SiMe3)(2)] (1) and [PhC(NtBu)(2)GeN(SiMe3)(2)] (4) with InCl3 and InBr3 that have resulted in the first silylene-indium complexes, [PhC(NtBu)(2)Si{N(SiMe3)(2)}-> InCl3] (2) and [PhC(NtBu)(2)Si{N(SiMe3)(2)}-> InBr3] (3), as well as the first germylene-indium complexes, [PhC(NtBu)(2)Ge{N(SiMe3)(2)}-> InCl3] (5) and [PhC(NtBu)(2)Ge{N(SiMe3)(2)}-> InBr3] (6). The solid-state structures of all species have been validated by single-crystal X-ray diffraction studies. Note that 5 and 6 are the first structurally characterized organometallic compounds that feature a Ge-In single bond (apart from the compounds in Zintl phases). Theoretical calculations reveal that the Si(II)-> In bonds in 2 and 3 and the Ge(II)-> In bonds in 5 and 6 are dative bonds.1 aPahar, Sanjukta1 aKarak, Suvendu1 aPait, Moumita1 aRaj, Vipin1 aVanka, Kumar1 aSen, Sakya, S. uhttps://library.ncl.res.in/content/access-siliconii-and-germaniumii-indium-compounds02690nas a2200229 4500008004100000022001400041245011000055210006900165260000900234300001400243490000800257520190300265100002202168700001502190700002302205700001702228700002402245700002402269700001802293700002402311856012502335 2018 eng d a0002-786300aIron Catalyzed Hydroformylation of Alkenes under Mild Conditions: Evidence of an Fe(II) Catalyzed Process0 aIron Catalyzed Hydroformylation of Alkenes under Mild Conditions cMAR  a4430-44390 v1403 a

Earth abundant, first row transition metals offer a cheap and sustainable alternative to the rare and precious metals. However, utilization of first row metals in catalysis requires harsh reaction conditions, suffers from limited activity, and fails to tolerate functional groups. Reported here is a highly efficient iron catalyzed hydroformylation of alkenes under mild conditions. This protocol operates at 10-30 bar syngas pressure below 100 degrees C, utilizes readily available ligands, and applies to an array of olefins. Thus, the iron precursor [HFe(CO)(4)](-)[Ph3PNPPh3](+) (1) in the presence of triphenyl phosphine catalyzes the hydroformylation of 1-hexene (S2), 1-octene (S1), 1-decene (S3), 1-dodecene (S4), 1-octadecene (S5), trimethoxy(vinyl)silane (S6), trimethyl(vinyl)silane (S7), cardanol (S8), 2,3-dihydrofuran (S9), allyl malonic acid (S10), styrene (S11), 4-methylstyrene (S12), 4-iBu-styrene (S13), 4-tBu-styrene (S14), 4-methoxy styrene (S15), 4-acetoxy styrene (S16), 4-bromo styrene (S17), 4-chloro styrene (S18), 4-vinylbenzonitrile (S19), 4-vinylbenzoic acid (S20), and allyl benzene (S21) to corresponding aldehydes in good to excellent yields. Both electron donating and electron withdrawing substituents could be tolerated and excellent conversions were obtained for S11-S20. Remarkably, the addition of 1 mol % acetic acid promotes the reaction to completion within 16-24 h. Detailed mechanistic investigations revealed in situ formation of an iron-dihydride complex [H2Fe(CO)(2)(PPh3)(2)] (A) as an active catalytic species. This finding was further supported by cyclic voltammetry investigations and intermediacy of an Fe(0)-Fe(II) species was established. Combined experimental and computational investigations support the existence of an iron-dihydride as the catalyst resting state, which then follows a Fe(II) based catalytic cycle to produce aldehyde.

1 aPandey, Swechchha1 aRaj, Vipin1 aShinde, Dinesh, R.1 aVanka, Kumar1 aKashyap, Varchaswal1 aKurungot, Sreekumar1 aVinod, C., P.1 aChikkali, Samir, H. uhttps://library.ncl.res.in/content/iron-catalyzed-hydroformylation-alkenes-under-mild-conditions-evidence-feii-catalyzed02056nas a2200241 4500008004100000022001400041245009200055210006900147260000800216300001600224490000800240520121300248100003801461700002601499700002901525700001801554700003301572700001801605700001501623700002401638700003001662856012201692 2019 eng d a0002-786300aImidazole-linked crystalline two-dimensional polymer with ultrahigh proton-conductivity0 aImidazolelinked crystalline twodimensional polymer with ultrahig cSEP a14950-149540 v1413 a

Proton-exchange membrane fuel cells are promising energy devices for a sustainable future due to green features, high power density, and mild operating conditions. A facile proton-conducting membrane plays a pivotal role to boost the efficiency of fuel cells, and hence focused research in this area is highly desirable. Major issues associated with the successful example of Nafion resulted in the search for alternate proton conducting materials. Even though proton carrier loaded crystalline porous organic frameworks have been used for protonconduction, the weak host-guest interactions limited their practical use. Herein, we developed a crystalline 2D-polymer composed of benzimidazole units as the integral part, prepared by the condensation of aryl acid and diamine in polyphosphoric acid medium. The imidazole linked-2D-polymer exhibits ultrahigh proton conductivity (3.2 X 10(-2) S cm(-1)) (at 95% relative humidity and 95 degrees C) in the pristine state, which is highest among the undoped porous organic frameworks so far reported. The present strategy of a crystalline proton-conducting 2D-polymer will lead to the development of new high performing crystalline solid proton conductor.

1 aRanjeesh, Kayaramkodath, Chandran1 aIlathvalappil, Rajith1 aVeer, Sairam, Dnyaneshwa1 aPeter, Joseph1 aWakchaure, Vivek, Chandrakan1 aGoudappagouda1 aRaj, Vipin1 aKurungot, Sreekumar1 aBabu, Sukumaran, Santhosh uhttps://library.ncl.res.in/content/imidazole-linked-crystalline-two-dimensional-polymer-ultrahigh-proton-conductivity01130nas a2200193 4500008004100000022001400041245012900055210006900184260000900253300001400262490000700276520042800283100002600711700001500737700001700752700001900769700002400788856012400812 2019 eng d a1359-734500aSilylene induced cooperative B-H bond activation and unprecedented aldehyde C-H bond splitting with amidinate ring expansion0 aSilylene induced cooperative BH bond activation and unprecedente cMAR  a3536-35390 v553 a

The addition of HBpin to PhC(NtBu)(2)SiN(SiMe3)(2) (1) results in the cleavage of the B-H bond in a cooperative fashion across the Si and amidinate-C sites. The reaction of 1 with benzaldehyde led to C-H bond activation with amidinate ring expansion leading to a five-membered heterocycle. In case of 4-fluorobenzaldehyde, a C-C bond coupling takes place leading to a dioxasilolane derivative as the major product.

1 aSwamy, V., S. V. S. N1 aRaj, Vipin1 aVanka, Kumar1 aSen, Sakya, S.1 aRoesky, Herbert, W. uhttps://library.ncl.res.in/content/silylene-induced-cooperative-b-h-bond-activation-and-unprecedented-aldehyde-c-h-bond01772nas a2200265 4500008004100000022001400041245007500055210006900130260000900199300001400208490000700222520099600229653000801225653001601233653001401249653002001263653000901283100001901292700001701311700001501328700002001343700001701363700001901380856010701399 2020 eng d a1861-472800aAmidinato germylene-zinc complexes: synthesis, bonding, and reactivity0 aAmidinato germylenezinc complexes synthesis bonding and reactivi cOCT  a3116-31210 v153 a

Despite the explosive growth of germylene compounds as ligands in transition metal complexes, there is a modicum of precedence for the germylene zinc complexes. In this work, the synthesis and characterization of new germylene zinc complexes [PhC(NtBu)(2)Ge{N(SiMe3)(2)}-> ZnX2](2)(X= Br (2) and I (3)) supported by (benz)-amidinato germylene ligands are reported. The solid-state structures of2and3have been validated by single-crystal X-ray diffraction studies, which revealed the dimeric nature of the complexes, with distorted tetrahedral geometries around the Ge and Zn center. DFT calculations reveal that the Ge-Zn bonds in2and3are dative in nature. The reaction of2with elemental sulfur resulted in the first structurally characterized germathione stabilized ZnBr(2)complexes PhC(NtBu)(2)Ge(=S){N(SiMe3)(2)}-> ZnBr2(5). Therefore, the Ge=S in5is in-between Ge-S single and Ge=S double bond length, owing to the coordination of a sulfur lone pair of electrons to ZnBr2.

10aDFT10aGermathione10aGermylene10aX-ray Structure10azinc1 aYadav, Sandeep1 aKumar, Rohit1 aRaj, Vipin1 aYadav, Prashant1 aVanka, Kumar1 aSen, Sakya, S. uhttps://library.ncl.res.in/content/amidinato-germylene-zinc-complexes-synthesis-bonding-and-reactivity01891nas a2200193 4500008004100000022001400041245011100055210006900166260000900235300001400244490000700258520120400265100002401469700002601493700001501519700001701534700001901551856012701570 2021 eng d a0020-166900aDiverse reactivity of hypersilylsilylene with boranes and threecomponent reactions with aldehyde and HBpin0 aDiverse reactivity of hypersilylsilylene with boranes and threec cFEB  a1654-16630 v603 a

The recently reported hypersilylsilylene PhC-(NtBu)(2)SiSi(SiMe3)(3) (1) reacts with BH3, 9-BBN, and PhBCl2 to yield the respective Lewis acid base adducts 2-4, respectively. Compound 4 undergoes isomerization to form a ring expansion product 5. The same silylene was found to initially form an adduct with HBpin (6) and subsequently isomerized to 7 via the rupture of the B-H bond of HBpin (7), where the hydride was bound to the carbon atom of the amidinate ligand and the Bpin unit was attached to the silicon center. Surprisingly, the reaction of 1 with HBcat results in PhC(NtBu)(2)Bcat (8). Subsequently, we have shown that HBcat forms the same product when it reacts with related silylene PhC(NtBu)(2)SiN(SiMe3)(3) (1'). With all of these reactions in hand, we ponder if silylene can activate two small molecules at one time. In this work, we delineate the three-component reactions of silylenes 1 and 1' with 4-fluorobenzaldehyde and HBpin, which afforded unusual coupling products, 9 and 10, respectively. Note that 9 and 10 were prepared from the cleavage of the B-H and C=O bonds by silylene in a single reaction and are the first structurally attested Si-C-O-B coupled products.

1 aBisai, Milan, Kumar1 aSwamy, V., S. V. S. N1 aRaj, Vipin1 aVanka, Kumar1 aSen, Sakya, S. uhttps://library.ncl.res.in/content/diverse-reactivity-hypersilylsilylene-boranes-and-threecomponent-reactions-aldehyde-and02407nas a2200205 4500008004100000022001400041245015600055210006900211260000900280300001400289490000700303520165600310100001801966700001701984700001802001700001502019700001702034700001902051856013102070 2022 eng d a2050-748800aAntimicrobial two-dimensional covalent organic nanosheets (2D-CONs) for the fast and highly efficient capture and recovery of phosphate ions from water0 aAntimicrobial twodimensional covalent organic nanosheets 2DCONs  cMAR  a4585-45930 v103 a

The retrieval of depleting resources from wastewater could help resolve the mounting demands for resources in our society. Phosphate is an essential nutrient for all living things. However, the diminution of global reserves of phosphate rock could significantly affect our food security in the near future. At the same time, the removal of phosphates and pathogens is of great importance for water security and de-eutrophication. The specific pH-dependent adsorption and desorption of phosphate ions by water-insoluble adsorbents is an exciting strategy for removing and recovering phosphates from contaminated water. Herein, we report the development of new two-dimensional guanidine-containing covalent organic nanosheets (2D-gCONs). This water-insoluble amorphous polymer (exfoliated) selectively sequestered phosphate ions in the presence of other competing anions and could be reused for multiple cycles. The polymer showed a fast removal of phosphate ions with a maximum adsorption capacity of 398 mg g(-1) (pH 7.0). The sequestered phosphate ions could be easily reclaimed, and the polymer could be recycled just by altering the pH (similar to 10.0) of the aqueous solution. The guanidinium moieties played a pivotal role in exfoliation in aqueous medium and in the antibacterial activities against Gram-negative and Gram-positive bacteria. We hypothesize that the current study may advance the design of water-insoluble CONs to remove and recover phosphate ions from wastewater and could help alleviate the negative impact of water eutrophication. This strategy can also be tweaked to address other severe environmental challenges.

1 aDey, Subhasis1 aDas, Sribash1 aPatel, Anjali1 aRaj, Vipin1 aVanka, Kumar1 aManna, Debasis uhttps://library.ncl.res.in/content/antimicrobial-two-dimensional-covalent-organic-nanosheets-2d-cons-fast-and-highly-efficient02053nas a2200277 4500008004100000022001400041245011600055210006900171260000800240300001500248490000900263520112800272653002901400653001401429653001901443653002201462653003101484100001701515700001701532700002201549700001501571700001701586700001701603700002401620856013101644 2022 eng d a1434-193X00aMechanistically guided one pot synthesis of phosphine-phosphite and its implication in asymmetric hydrogenation0 aMechanistically guided one pot synthesis of phosphinephosphite a cJAN ae2021014470 v20223 a

Although hybrid bidentate ligands are known to yield highly enantioselective products in asymmetric hydrogenation (AH), synthesis of these ligands is an arduous process. Herein, a one pot, atom-economic synthesis of a hybrid phosphine-phosphite (L1) is reported. After understanding the reactivity difference between an 0-nucleophile versus C-nucleophile, one pot synthesis of Senphos (L1) was achieved (72%). When L1 was treated with [Rh], P-31 NMR revealed bidentate coordination to Rh. Senphos, in the presence of rhodium, catalyzes the AH of Methyl-2-acetamido-3-phenylacrylate and discloses an unprecedented turn over frequency of 2289, along with excellent enantio-selectivity (92%). The generality is demonstrated by hydrogenating an array of alkenes. The AH operates under mild conditions of 1-2 bar H-2 pressure, at room temperature. The practical relevance of Ll is demonstrated by scaling-up the reaction to 1 g and by synthesizing DOPA, a drug widely employed for the treatment of Parkinson's disease. Computational insights indicate that the R isomer is preferred by 3.8 kcal/mol over the S isomer.

10aasymmetric hydrogenation10acatalysis10aDOPA synthesis10aOne pot synthesis10aPhosphine-phosphite ligand1 aSen, Anirban1 aKumar, Rohit1 aPandey, Swechchha1 aRaj, Vipin1 aKumar, Pawan1 aVanka, Kumar1 aChikkali, Samir, H. uhttps://library.ncl.res.in/content/mechanistically-guided-one-pot-synthesis-phosphine-phosphite-and-its-implication-asymmetric01271nas a2200205 4500008004100000022001400041245011800055210006900173260000900242300001400251490000700265520055300272100001700825700002300842700001500865700001700880700001900897700001900916856013000935 2022 eng d a1359-734500aSubstitution at sp(3) boron of a six-membered NHC center dot BH3: convenient access to a dihydroxyborenium cation0 aSubstitution at sp3 boron of a sixmembered NHC center dot BH3 co cMAR  a3783-37860 v583 a

Herein, we have undertaken the synthesis and investigated the reactivity of a 6-membered saturated NHC borane adduct (1). Direct electrophilic halogenation of 1 with a stoichiometric amount of I-2 led to NHC boryl iodides, 6-SIDipp center dot BH2I (2) and 6-SIDipp center dot BHI2 (3), which were further reacted with various nucleophiles to give novel 6-SIDipp based mono and disubstituted boranes with OTf (4 and 6) or ONO2 (5 and 7) functional groups. The addition of Br-2/H2O to 1 smoothly results in a dihydroxyborenium cation (8).

1 aKundu, Gargi1 aAjithkumar, V., S.1 aRaj, Vipin1 aVanka, Kumar1 aTothadi, Srinu1 aSen, Sakya, S. uhttps://library.ncl.res.in/content/substitution-sp3-boron-six-membered-nhc-center-dot-bh3-convenient-access-dihydroxyborenium01978nas a2200169 4500008004100000022001400041245011700055210006900172260000800241300001400249490000800263520134800271100001501619700002701634700001701661856013001678 2023 eng d a1932-744700aPotential role of lewis acid-base adducts in enhancing stereoselectivity in ziegler-natta catalysts: a DFT study0 aPotential role of lewis acidbase adducts in enhancing stereosele cAPR a7220-72290 v1273 a

Ziegler-Natta (Z-N) systems have been well established as heterogeneous catalysts that produce isotactic polypropylene and polyethylene with great efficiency. Such systems benefit considerably from donors (Lewis bases), whose addition significantly improves the stereoselectivity of polymerization. There is a consensus that the primary role of the external donors is to coordinate at the vacant site created by the extraction of internal donors and thus maintain the stereoselectivity. However, the bite difference between internal donors such as phthalates or succinate derivatives and external donors such as alkoxysilanes raises the question of how external donors can effectively replace internal donors. In order to investigate this, we have chosen four external alkoxysilane donors: (1) diisopropyl dimethoxysilane, (2) dicyclopentyl dimethoxysilane, (3) disec-butyl dimethoxysilane, and (4) sec-butyl(methyl) dimethoxysilane. DFT studies reveal that the bite difference problem can be overcome by the favorable formation of adducts between the alkoxysilane external donors and AlEt2Cl in the Z-N systems. These adducts tend to coordinate in the vicinity of the active site. Furthermore, our findings demonstrate the potential of these Lewis acid-base adducts to enhance the stereoselectivity of Z-N catalysts significantly.

1 aRaj, Vipin1 aGupta, Virendra, Kumar1 aVanka, Kumar uhttps://library.ncl.res.in/content/potential-role-lewis-acid-base-adducts-enhancing-stereoselectivity-ziegler-natta-catalysts01647nas a2200205 4500008004100000022001400041245010700055210006900162260000800231300001400239490000700253520092900260100002301189700002701212700001501239700001701254700002401271700001901295856012701314 2023 eng d a0276-733300aSynthesis of Si(IV)- and Ge(II)-substituted amines, hydrazone, and hydrazine from hypersilyl germylene0 aSynthesis of SiIV and GeIIsubstituted amines hydrazone and hydra cOCT a2983-29900 v423 a

This study investigates the reactivity of a hypersilyl germylene [PhC-(NtBu)(2)GeSi-(SiMe3)(3)] (1) with various organic compounds including azides, diazoalkanes, 1,2-diphenylhydrazine, and trifluoroacetophenone. The reactivity observed in these reactions is driven by the insertion of the organic fragment between a silicon and germanium bond. This leads to the formation of novel compounds, including an amine featuring three different substituents from three different elements of group 14. When reacting with Me3SiCHN2, we observed the insertion of the diazoalkane fragment in an end-on fashion into the Ge-Si bond. An analogous trend was observed in reactions with 1,2-diphenylhydrazine and trifluoroacetophenone, where the N-N and C-O fragments were inserted into the Ge-Si bond. Multinuclear NMR and single-crystal X-ray diffraction analyses were conducted to characterize the newly synthesized compounds.

1 aAjithkumar, V., S.1 aGhanwat, Pratiksha, B.1 aRaj, Vipin1 aVanka, Kumar1 aGonnade, Rajesh, G.1 aSen, Sakya, S. uhttps://library.ncl.res.in/content/synthesis-siiv-and-geii-substituted-amines-hydrazone-and-hydrazine-hypersilyl-germylene01444nas a2200205 4500008004100000022001400041245003200055210003200087260000800119300001400127490000700141520092000148100001701068700002001085700001501105700001901120700001701139700001901156856006301175 2023 eng d a2041-652000aTaming the parent oxoborane0 aTaming the parent oxoborane cJUN a5894-58980 v143 a

Despite recent advancements in the chemistry of multiply bound boron compounds, the laboratory isolation of the parent oxoborane moiety, HBO has long remained an unsolved and well-recognized challenge. The reaction of 6-SIDipp(.)BH3 [6-SIDipp = 1,3-di(2,6-diisopropylphenyl)tetrahydropyrimidine2-ylidene] with GaCl3 afforded an unusual boron-gallium 3c-2e compound (1). The addition of water to 1 resulted in the release of H-2 and the formation of a rare acid stabilized neutral parent oxoborane, LB(H)]O (2). Crystallographic and density functional theory (DFT) analyses support the presence of a terminal B=O double bond. Subsequent addition of another equivalent of water molecule led to hydrolysis of the B-H bond to the B-OH bond, but the `B=O' moiety remained intact, resulting in the formation of the hydroxy oxoborane compound (3), which can be classified as a monomeric form of metaboric acid.

1 aKundu, Gargi1 aAmrutha, P., R.1 aRaj, Vipin1 aTothadi, Srinu1 aVanka, Kumar1 aSen, Sakya, S. uhttps://library.ncl.res.in/content/taming-parent-oxoborane01098nas a2200205 4500008004100000022001400041245006100055210006100116260000900177300001400186490000700200520047500207100002400682700002300706700001500729700001700744700002400761700001900785856008800804 2023 eng d a1359-734500aZwitterionic disilanylium from an unsymmetrical disilene0 aZwitterionic disilanylium from an unsymmetrical disilene cFEB  a1669-16720 v593 a

The reaction of PhC(NtBu)2SiSi(SiMe3)(3) (1) with Me3SiCH(2)Cl afforded an unsymmetrical sp(2)-sp(3) disilene, 2, with concomitant elimination of Me3SiCl. The analogous reaction with PhC(NtBu)2SiCl resulted in the oxidative addition of the C-Cl bond at the Si(II) atom (3). The reactions of 2 with sulfur and selenium led to compounds with Si=E (E=S (4) and Se (5)) double bonds. Tellurium reacted differently with 2 and furnished a zwitterionic compound, 6.

1 aBisai, Milan, Kumar1 aAjithkumar, V., S.1 aRaj, Vipin1 aVanka, Kumar1 aGonnade, Rajesh, G.1 aSen, Sakya, S. uhttps://library.ncl.res.in/content/zwitterionic-disilanylium-unsymmetrical-disilene02041nas 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-synthesis02167nas a2200289 4500008004100000022001400041245005500055210005200110260000800162490000700170520133100177653002301508653002401531653001901555653001101574653002201585100002001607700001901627700001501646700002301661700002401684700002101708700001701729700002401746700001901770856008801789 2024 eng d a0947-653900aTridentate NacNac tames T-shaped nickel(I) radical0 aTridentate NacNac tames Tshaped nickelI radical cFEB0 v303 a

The reaction of a nickel(II) chloride complex containing a tridentate beta-diketiminato ligand with a picolyl group [2,6-iPr2-C6H3NC(Me)CHC(Me)NH(CH2py)]Ni(II)Cl (1)] with KSi(SiMe3)3 conveniently afforded a nickel(I) radical with a T-shaped geometry (2). The compound's metalloradical nature was confirmed through electron paramagnetic resonance (EPR) studies and its reaction with TEMPO, resulting in the formation of a highly unusual three-membered nickeloxaziridine complex (3). When reacted with disulfide and diselenide, the S-S and Se-Se bonds were cleaved, and a coupled product was formed through carbon atom of the pyridine-imine group. The nickel(I) radical activates dihydrogen at room temperature and atmospheric pressure to give the monomeric nickel hydride. A thermally stable, T-shaped, nickel(I) radical was straightforward obtained by reduction of a tridentate nacnac nickel(II) chloride with KSi(TMS)3. The metalloradical character of the compound was demonstrated by the formation of a highly unusual nickeloxaziridine complex upon addition of TEMPO. The Ni(I) species displays a rich chemistry towards activation S-S, and Se-Se bond leading to unusual C-C coupled product as well as dihydrogen activation at room temperature and atmospheric pressure to generate monomeric nickel hydride.+image

10aC-C Bond formation10aHydrogen Activation10aMetalloradical10aNickel10aTridentate nacnac1 aPahar, Sanjukta1 aSharma, Vishal1 aRaj, Vipin1 aSangole, Mayur, P.1 aGeorge, Christy, P.1 aSingh, Kirandeep1 aVanka, Kumar1 aGonnade, Rajesh, G.1 aSen, Sakya, S. uhttps://library.ncl.res.in/content/tridentate-nacnac-tames-t-shaped-nickeli-radical01411nas a2200217 4500008004100000022001400041245009500055210006900150260000800219300001400227490000700241520068000248100002300928700002400951700002700975700001501002700001901017700001701036700001901053856012101072 2025 eng d a0276-733300aHypersilylsilylene-supported Ni(0) toluene and Ni(II) complexes with catalytic application0 aHypersilylsilylenesupported Ni0 toluene and NiII complexes with  cNOV a2646-26530 v443 a

The reaction of Ni(COD)2 with [PhC(NtBu)2SiSi(SiMe3)3] (1) in toluene results in the formation of an 18-electron silylene-Ni(0) toluene complex (2). The analogous reaction with 1,3-DFB instead of toluene affords the C-H activation followed by ring walking leading to the allylic cyclooctene adduct, the (eta 3-C8H13)Ni(II) complex (3). DFT calculations were carried out to elucidate the mechanism as well as to gain insight into why 1,3-DFB undergoes C-H bond activation instead of C-F bond activation. The use of NiCl2DME permits access to 16-electron (tetrylene)2NiCl2 (Si(4) and Ge(5)) species, and 4 was later used as a catalyst for the C-N coupling reaction.

1 aAjithkumar, V., S.1 aBisai, Milan, Kumar1 aGhanwat, Pratiksha, B.1 aRaj, Vipin1 aSingh, Geetika1 aVanka, Kumar1 aSen, Sakya, S. uhttps://library.ncl.res.in/content/hypersilylsilylene-supported-ni0-toluene-and-niii-complexes-catalytic-application