02090nas a2200193 4500008004100000245005500041210005300096260000800149300001600157490000700173520150800180100002401688700002601712700001501738700001701753700002401770700001901794856008301813 2019 eng d00a Synthesis and reactivity of a hypersilylsilylene 0 aSynthesis and reactivity of a hypersilylsilylene cAUG a10536-105420 v583 a

Stabilization of an amidinatosilylene with a bulky tris(trimethylsilyl)silyl substituent was realized with the preparation of PhC(NtBu)(2)Si{Si(SiMe3)(3)} (1) from PhC(NtBu)(2)SiHCl2 with K{Si(SiMe3)(3)} in more than 90% yield. The highly deshielded Si-29 NMR resonance (delta = 76.91 ppm) can be attributed to the absence of a pi-donating substituent. The molecular structure of 1 shows a trigonal-planar geometry around the Si-II center with a Si-II-Si-IV bond length of 2.4339(13) angstrom. A series of reactions of 1 with Me3NO, S, Se, and Te were performed. While siloxane derivatives (2 and 3) are obtained from reactions with Me3NO, silachalcogenones (4-6) are formed with other chalcogens. The presence of Si=E (E = S, Se, and Te) bonds in 4-6 have been confirmed by single crystal X-ray studies. Silaoxirane (7) formation was observed when 1 was treated with acetone, demonstrating the importance of the tris(trimethylsilyl)silyl group to kinetically and thermodynamically protect the silaoxirane derivative with less bulky substituents on the C atom.

1 aBisai, Milan, Kumar1 aSwamy, V., S. V. S. N1 aDas, Tamal1 aVanka, Kumar1 aGonnade, Rajesh, G.1 aSen, Sakya, S. uhttps://library.ncl.res.in/content/synthesis-and-reactivity-hypersilylsilylene01850nas a2200205 4500008004100000022001400041245011800055210006900173260000800242300001400250490000700264520113500271100001701406700002401423700001901447700001801466700001901484700001701503856012401520 2021 eng d a0276-733300aSubstrate, catalyst, and solvent: the triune nature of multitasking reagents in hydroboration and cyanosilylation0 aSubstrate catalyst and solvent the triune nature of multitasking cAPR a1104-11120 v403 a

A truly green chemical process would avoid the use of an external catalyst, while still achieving high efficiency. This has been realized in the very recent past for hydroboration, cyanosilylation, acetalization, and the aza-Michael addition, among other reactions. The current combined computational and experimental study unlocks the secret to how this highly desirable outcome is accomplished: one of the reactants in the process also acts as the catalyst. Specifically, this is shown (i) for the important hydroboration reaction, with pinacolborane (HBpin) as the hydroborating reagent and benzaldehyde, acetophenone, benzoic acid and p-methoxyphenylacetylene as the hydroborated substrates, and (ii) for cyanosilylation, with trimethylcyanosilane (TMSCN) as the cyanosilylating agent and benzaldehyde as the substrate. The mechanistic understanding thus gained has then been further exploited experimentally to bring hydroboration and cyanosilylation closer to experimental conditions in catalysis. These insights can potentially be expanded to the rapidly growing area of solvent-free and internal catalyst chemistry.

1 aDixit, Ruchi1 aBisai, Milan, Kumar1 aYadav, Sandeep1 aYadav, Vinita1 aSen, Sakya, S.1 aVanka, Kumar uhttps://library.ncl.res.in/content/substrate-catalyst-and-solvent-triune-nature-multitasking-reagents-hydroboration-and01480nas a2200241 4500008004100000022001400041245005100055210004900106260000900155490000700164520078200171653001700953653002000970653001600990653002101006653002601027100002301053700002401076700001601100700002401116700001901140856007901159 2025 eng d a1434-194800aSila[1]ferrocenophanes with Bulky Substituents0 aSila1ferrocenophanes with Bulky Substituents cMAY 0 v283 a

In this study, sila[1]ferrocenophanes with sterically bulky groups such as tris(trimethylsilyl) or N-heterocyclic iminato located at the bridging silicon atom are synthesized. The reactions of silicon-bound chloride in Fe(eta 5-C5H4)2SiCl2 (1) with K[Si(SiMe3)3] and silylated N-heterocyclic imine result in sila[1]ferrocenophanes 2 and 3 with bulky silicon- and nitrogen-based substituents at the ansa-bridge via elimination of KCl and Me3SiCl. Subsequently, the reduction of 1 is attempted using 2,3,5,6-tetramethyl-1,4-bis(trimethylsilyl)-1,4-dihydropyrazine (popularly known as Mashima reagent), which leads to the elimination of Me3SiCl and generation of 1,4-dihydropyrazine-spanned sila[1]ferrocenophanes (4). All the compounds are structurally characterized.

10aansa-bridges10aferrocenophanes10ahypersilyls10aMashima reagents10aN-heterocyclic imines1 aAjithkumar, V., S.1 aBisai, Milan, Kumar1 aYuvaraj, K.1 aGonnade, Rajesh, G.1 aSen, Sakya, S. uhttps://library.ncl.res.in/content/sila1ferrocenophanes-bulky-substituents