Stabilization of an amidinatosilylene with a bulky tris(trimethylsilyl)silyl substituent was realized with the preparation of PhC(NtBu) 2 Si{Si(SiMe 3 ) 3 } (1) from PhC-(NtBu) 2 SiHCl 2 with K{Si(SiMe 3 ) 3 } in more than 90% yield. The highly deshielded 29 Si NMR resonance (δ = 76.91 ppm) can be attributed to the absence of a π-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) Å. A series of reactions of 1 with Me 3 NO, S, Se, and Te were performed. While siloxane derivatives (2 and 3) are obtained from reactions with Me 3 NO, 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 singlecrystal 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.

Simple and readily accessible lithium compounds such as 2,6-di-tert-butyl phenolate lithium (1a), 1,1' dilithioferrocene (1b) and nacnac lithium (1c) are found to be efficient single site catalysts for hydroboration of a range of aldehydes and ketones with HBpin at room temperature. The efficacy of 1a-1c as catalysts is extended to the cyanosilylation of aldehydes and ketones with Me3SiCN.

N-Heterocyclic carbene (NHC) catalysis has been widely used for the umpolung of aldehydes, and recently for the umpolung of Michael acceptors. Described herein is the umpolung of aldimines catalyzed by NHCs, and the reaction likely proceeds via aza-Breslow intermediates. The NHC-catalyzed intramolecular cyclization of aldimines bearing a Michael acceptor resulted in the formation of biologically important 2-(hetero)aryl indole 3-acetic-acid derivatives in moderate to good yields. The carbene generated from the bicyclic triazolium salt was found to be efficient for this transformation.