01928nas a2200229 4500008004100000022001400041245008600055210006900141260000800210300001600218490000700234520116200241100002001403700002501423700002301448700001901471700002701490700002701517700002101544700001801565856011501583 2022 eng d a0020-166900aFirst-row transition metal complexes of a phosphine-silylene- based hybrid ligand0 aFirstrow transition metal complexes of a phosphinesilylene based cAUG a13330-133410 v613 a

We have prepared two new silylene-phosphine-based hybrid ligands Si{N(R)C6H4(PPh2)}{PhC((NBu)-Bu-t)(2)} [R = TMS {trimethylsilyl} (1) and TBDMS {tert-butyldimethylsilyl} (2)], which possess two donor sites. Furthermore, the treatment of the bidentate ligand 1 with base metal halides {FeBr2, CoBr2, NiCl(2)middotdme [nickel chloride(II) ethylene glycol dimethyl ether]} and 2 with NiBr(2)middotdme [nickel bromide(II) ethylene glycol dimethyl ether] afforded four-coordinate six-membered metal complexes 3-6, respectively, which feature coordination from both Si(II) and P(III) sites. Subsequently, complexes 3 [(FeBr2)Si{N(SiMe3)C6H4(PPh2)}{PhC((NBu)-Bu-t)(2)}], 4 [(CoBr2)Si{N(SiMe3)C6H4(PPh2)}{PhC((NBu)-Bu-t)(2)}], 5 [(NiCl2)Si{N(SiMe3)C6H4(PPh2)}{PhC((NBu)-Bu-t)(2)}], and 6 [(NiBr2)Si{N((SiBuMe2)-Bu-t)C6H4(PPh2)}{PhC((NBu)-Bu-t)(2)}] are studied for their redox and magnetic properties with the help of UV-vis spectroscopy, cyclic voltammetry, SQUID magnetometry, and theoretical calculations. Complexes 3-6 were found to display a paramagnetic behavior. All the compounds are well established by single-crystal X-ray diffraction studies.

1 aAkhtar, Ruksana1 aKaulage, Sandeep, H.1 aSangole, Mayur, P.1 aTothadi, Srinu1 aParvathy, Parameswaran1 aParameswaran, Pattiyil1 aSingh, Kirandeep1 aKhan, Shabana uhttps://library.ncl.res.in/content/first-row-transition-metal-complexes-phosphine-silylene-based-hybrid-ligand01202nas a2200181 4500008004100000022001400041245010700055210006900162260000900231300001400240490000700254520054100261100002500802700002000827700002400847700001800871856013100889 2024 eng d a1359-734500aHybrid silylene-Pd catalyst: efficient C-N cross-coupling of sterically bulky amines and chiral amines0 aHybrid silylenePd catalyst efficient CN crosscoupling of sterica cSEP  a9958-99610 v603 a

Herein, we report a catalytic system with N-heterocyclic silylene (NHSi)-phosphine-based hybrid bidentate ligands [PhC(NtBu)2SiN(PR2)(2,6-iPr2-C6H3)] and Pd(dba)2, which serves as an effective catalyst for C-N cross-coupling of a wide range of sterically bulky amines and optically active amines, which is challenging otherwise. Herein, we report a hybrid silylene-based bidentate ligand (SiNP)-Pd(0) catalytic system, which performs the C-N coupling of difficult substrates, e.g., sterically bulky amines and chiral amines.

1 aKaulage, Sandeep, H.1 aParvin, Nasrina1 aKhopade, Kishor, V.1 aKhan, Shabana uhttps://library.ncl.res.in/content/hybrid-silylene-pd-catalyst-efficient-c-n-cross-coupling-sterically-bulky-amines-and-chiral01595nas a2200205 4500008004100000022001400041245012900055210006900184260000800253300001400261490000700275520082600282100002901108700003001137700002301167700002801190700002501218700002101243856012501264 2025 eng d a1477-052000aRongalite-promoted self-dimerization of 3-acylidene-2-oxindoles: a diastereoselective route to synthesis of bispirooxindoles0 aRongalitepromoted selfdimerization of 3acylidene2oxindoles a dia cOCT a8687-86940 v233 a

A facile and efficient one-pot rongalite-mediated self-dimerization of 3-acylidene-2-oxindoles has been developed for the diastereoselective synthesis of highly functionalized dispirocyclopentanebisoxindoles. The reaction proceeds via a domino sequence involving intermolecular Michael addition followed by intramolecular aldol cyclization under basic conditions. Rongalite, an inexpensive and readily available reagent (similar to\$0.03 per g), plays a crucial role in promoting the transformation, offering significant advantages such as operational simplicity, step economy, scalability to gram-scale synthesis, and potential for post-functionalization. This methodology provides an efficient route to structurally complex oxindole frameworks with high stereocontrol, demonstrating broad synthetic utility.

1 aChaudhari, Suryakant, S.1 aNichinde, Chandrakant, B.1 aPatil, Baliram, R.1 aGirase, Amardipsing, S.1 aKaulage, Sandeep, H.1 aKinage, Anil, K. uhttps://library.ncl.res.in/content/rongalite-promoted-self-dimerization-3-acylidene-2-oxindoles-diastereoselective-route01079nas a2200205 4500008004100000022001400041245008300055210006900138260000800207300001600215490000700231520039700238100002500635700002200660700002300682700002100705700001700726700001800743856011200761 2025 eng d a1359-734500aSilylene-copper(i) catalysis: regioselective protoboration of terminal alkynes0 aSilylenecopperi catalysis regioselective protoboration of termin cDEC a19652-196550 v613 a

Herein, we report an efficient regioselective protoboration of the terminal alkynes catalyzed by newly synthesized silylene-copper(i)-aryl complexes. This method offers a broad substrate scope, good functional-group compatibility, and a gram-scale synthetic ability. The insight into the mechanistic cycle is also provided with the support of experimental and theoretical studies.

1 aKaulage, Sandeep, H.1 aShah, Brij, Kumar1 aPanday, Rishukumar1 aSharma, Himanshu1 aVanka, Kumar1 aKhan, Shabana uhttps://library.ncl.res.in/content/silylene-copperi-catalysis-regioselective-protoboration-terminal-alkynes02889nas a2200277 4500008004100000022001400041245010900055210006900164260000800233300001100241490000800252520196700260653002002227653002502247653001702272653002302289653001102312100002802323700001702351700002402368700002502392700002202417700002302439700002402462856012502486 2026 eng d a0014-305700aSteric-bulk directed polymerization of ethylene to disentangled ultra-high molecular weight polyethylene0 aStericbulk directed polymerization of ethylene to disentangled u cJUN a1147620 v2533 a

{The electron-withdrawing pentafluorophenyl phenoxy-imine-derived titanium complexes are known to produce ultrahigh molecular weight polyethylene (UHMWPE). However, cyclohexyl phenoxy-imine-derived zirconium complexes have been reported to produce low molecular weight polyethylene. The disparity between the two types of polyethylenes and the two types of catalysts can be bridged if a titanium complex bearing sterically bulky groups is made to produce UHMWPE. We report steric bulk-directed cyclohexyl phenoxy-imine titaniumcatalyzed synthesis of UHMWPE in a disentangled state. The influence of steric bulk in a phenoxy-imine-cyclohexyl ligand framework on titanium complex formation and subsequent ethylene polymerization was investigated through a combined computational and experimental approach. Density functional theory (DFT) and buried volume analyses indicated that increasing steric demand from -H to -Me to -tert-Bu substituents enhances the buried volume around the metal center, potentially favoring high molecular weight polyethylene formation. Guided by these insights, three ligands, L1-L3, were synthesized in excellent yields and fully characterized, including by single-crystal X-ray diffraction. Treatment of L1-L3 with a titanium precursor produced respective complexes, Cat.1-Cat.3, in good yields. These were characterized by NMR, IR, MS, and single-crystal X-ray diffraction. Upon activation with various co-catalysts [methyl aluminoxane (MMAO), triisobutylaluminum (TIBA), and tetrakis (pentafluoro phenyl) borate (BT)], these complexes initiated ethylene polymerizations. The catalytic activity increased from Cat.1 to Cat.2 with growing steric bulk, but decreased for the highly hindered Cat.3, likely due to restricted monomer access to the active site. Among the three, Cat.2, in combination with MMAO, showed the best performance under optimized conditions and produced ultrahigh molecular weight polyethylene (UHMWPE

10aMetal catalysis10aPhenoxy-imine ligand10aPolyethylene10aTitanium complexes10auHMWPE1 aBodkhe, Dnyaneshwar, V.1 aPatel, Ketan1 aShaikh, Maulali, H.1 aKaulage, Sandeep, H.1 aMahajan, Digvijay1 aPol, Harshawardhan1 aChikkali, Samir, H. uhttps://library.ncl.res.in/content/steric-bulk-directed-polymerization-ethylene-disentangled-ultra-high-molecular-weight