Synthesis and Reactivity of a Stable Silylene

Abstract

The synthesis and several reactions of the stable silylene 1 (1,3-di-tert-butyl-2,3-dihydro-1H-1,3,2diazasilol-2-ylidene) are described. X-ray crystal structures are given for two intermediates in the synthesis of 1, the diimine 7 and its dilithium salt 8, and for a byproduct, the spiro compound 10. 1 reacts with ethanol and water by inserting into the O-H bond, and with iodomethane by insertion into the C-I bond. The silanol from reaction of 1 with water condenses to a disiloxane, 13. From 1 and sulfur and selenium, cyclic compounds containing Si 2 E 2 rings are obtained (E ) S or Se). Crystal structures are presented for disiloxane 13 and for the sulfur and selenium cycloadducts, 15 and 17.

Metal‐Free Activation of EH3 (E=P, As) by an Ylide‐like Silylene and Formation of a Donor‐Stabilized Arsasilene with a HSiAsH Subunit

“…For example, strong Lewis and Brønsted acids add to the exocyclic electron-rich methylene group [11] (compounds 4 a,b, Scheme 1), whereas the silicon(II) lone pair can be utilized as a strong s donor for the preparation of silylene-metal complexes, as shown for complex 5 in which the zwitterionic character of the ligand is retained. [12] The 1,1-addition to the silicon center, which is also well-documented for other NHSis, [13] and the 1,4-addition across the C 3 N 2 Si heterocycle are the most common reactivity features of 2. Both pathways have even been observed simultaneously during the reaction of water with two equivalents of NHSi 2 to yield donor-stabilized siloxysilylene 6 (Scheme 1).…”

Analysis of the crystal structures of 1,3‐di‐tert‐butyl‐2,3‐dihydro‐1H‐1,3,2‐diazasilol‐2‐ylidene and 1,3‐di‐tert‐butyl‐2,2‐dichloro‐1,3‐diaza‐2‐sila‐4‐cyclopentene

“…The title compounds were synthesized according to literature methods [4]. Crystals suitable for X-ray diffraction were sublimed at room temperature at 10 -4 Torr.…”

Versatile Reactivity of a Zwitterionic Isolable Silylene toward Ketones: Silicon‐Mediated, Regio‐ and Stereoselective CH Activation

“…Since the successful synthesis and isolation of several stable silylenes, [4] including the zwitterionic silylene 1 (Scheme 1), [5] their fascinating reactivity toward a variety of substrates, such as haloalkanes, halosilanes, [6] alkali metal amides, [7,8] alkenes, alkynes, [9,10] alcohols, [11][12][13] as well as white phosphorus, [14] has been a matter of numerous investigations. Accordingly, silylenes can be valuable building blocks in organic synthesis, for which the generated organosilicon group can serve as a protecting group for further chemical transformations.…”