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We report on the insertion of electron deficient alkyne, dimethyl acetylene dicarboxylate (DMAD), into the E–Si bond of hypersilyl tetrylenes, PhC(NtBu)2ESi(SiMe3)3 (E = Ge and Sn), at room temperature. Uniquely, the germylene leads to cis alkenes, while the stannylene gives access to trans alkenes, and the insight into divergent stereoselectivity has been obtained by DFT studies. [ABSTRACT FROM AUTHOR]

In this work, the insertion of CS2 into the Ge–Si bond of PhC(NtBu)2Ge–Si(SiMe3)3 (1) has been investigated, resulting in the formation of PhC(NtBu)2Ge–C(＝S)–S–Si(SiMe3)3 (2). Interestingly, the addition of NHC to 2 allows the release of NHC·CS2 with concomitant regeneration of 1. Addition of another equivalent of 1 or an analogous hypersilyl silylene, [PhC(NtBu)2Si–Si(SiMe3)3], to 2 led to the formation of compounds with a Ge＝S (3) or a Si＝S (4) bond. [ABSTRACT FROM AUTHOR]

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 I2 led to NHC boryl iodides, 6-SIDipp·BH2I (2) and 6-SIDipp·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 Br2/H2O to 1 smoothly results in a dihydroxyborenium cation (8). [ABSTRACT FROM AUTHOR]