Reaction of dimesitylsilylene with epoxides. Silanone–epoxide adducts

Abstract

Dimesitylsilylene, generated by photolysis of 2,2-dimesitylhexamethyltrisilane (1) , reacts with epoxides to give dimesitylsilanone-epoxide adducts. M e g MeRECENTLY, considerable interest has been focused on highly reactive unsaturated silicon intermediates.' How-

Strained‐Ring and Double‐Bond Systems Consisting of the Group 14 Elements Si, Ge, and Sn

“…Furthermore, the C,Si-Si framework is West has proposed a bonding model in which a significant amount of the double-bond character of the disilene is retained in 104c. The large 1J29si-29si coupling constant of 99 Hz measured for 106, which is intermediate between that of disilenes (155 Hz) and disilanes (55)(56)(57)(58)(59)(60)(61)(62)(63)(64)(65)(66)(67)(68)(69)(70), indicates that the oxadisilirane 104c may be described as a n complex 107. "01i9 l Z 1 l (The 1J29si-29si of cyclotrisilane is small-24 Hz; see Section 4.3.3.…”

Silanones and Silanethiones from the Reactions of Transient Silylenes with Oxiranes and Thiiranes in Solution. The Direct Detection of Diphenylsilanethione.

“…[10][11][12][13] Early product-and kinetic studies of the reactions of SiMe 2 with the parent oxirane and various substituted derivatives were interpreted in terms of a multistep mechanism involving the initial formation of a silylene-oxirane complex. [10][11][12]14,15 Tzeng and Weber proposed that the collapse of the complex proceeds via a stepwise mechanism involving a zwitterionic intermediate, in order to account for the formation of siloxacyclohexenes in the reactions of SiMe 2 with vinyl epoxides, in addition to dimethylsilanone and the corresponding diene (eq 2). 11 Various details of the mechanism have received support from subsequent theoretical calculations, [16][17][18] and by recent kinetic studies of the reaction of SiH 2 with oxirane in the gas phase.…”

A combined kinetic and computational study of the reactions of transient germylenes with oxiranes and thiiranes in solution

“…The present work represents the first experimental study to be reported of the reactivity of simple, transient dialkyl-and diarylgermylenes with oxiranes and thiiranes under neutral ambient conditions, conditions under which the corresponding silylene derivatives react rapidly via formal oxygen or sulfur abstraction to afford the corresponding alkene and silanone [27][28][29][30][31]38 or silanethione, 31 respectively, in good chemical yields. The only related existing studies of the reactivity of Ge(II) systems with substrates of this type are those of Satgé and co-workers, who examined the reactions of a series of amine-coordinated germylenoids with oxiranes and thiirane.…”

“…28,29,31 (2) or MeOH, 31 the products of which are formed along with the corresponding alkenes in yields of 50%-70% relative to consumed silylene precursor. Transient silanones have also been shown to react with dienes 27 and oxiranes 30 to form stable products.…”

“…9,10 Stable silane-and germanethiones have also been prepared by abstraction reactions involving sterically encumbered or donor-stabilized tetrylenes, for example with phenyl isothiocyanate or styrene episulfide 11 as sulfur donors; 12 the desulfurization of sila-and germatetrathiolanes is another commonly used method for the preparation of stable M=S bondcontaining compounds. [13][14][15] Silanones are suspected intermediates in the reactions of transient silylenes with substrates such as N 2 O, [16][17][18][19][20][21] CO 2 , 22 aryl nitrile oxides, 23 aryl-and alkylisocyanates, 11 dialkylsulfoxides, [24][25][26] and oxiranes; [27][28][29][30][31] formal oxygen abstraction from oxiranes has also been found to proceed with transient germylenes in the presence of amines. [32][33][34][35][36] The only tetrylene-derived method for the formation of transient silane-and germanethiones that has been reported is sulfur abstraction from thiiranes.…”