Hydrosilylation of Carbonyls Catalyzed by the Rhenium(V) Oxo Complex [Re(O)(hoz)(2)](+)-A Non-Hydride Pathway

作者：Gu, Piao; Wang, Wenmin; Wang, Yiou; Wei, Haiyan^*

来源：Organometallics, 2013, 32(1): 47-51.

DOI：10.1021/om300605j

• SILANE SIGMA-COMPLEXES
• SPECTROSCOPIC CHARACTERIZATION
• CATIONIC ETA(2)-SILANE
• SI-H
• REDUCTION
• BOND
• RUTHENIUM
• MECHANISM
• SYSTEM
• OXYGEN

Catalytic conversion of silane and carbonyls by the cationic rhenium oxo complex [Re(O)(hoz)(2)](+) (1; hoz = 2-(2'-hydroxyphenyl)-2-oxazoline(1-)) was examined using density functional theory. It is shown that complex 1 catalyzed the carbonyl hydrosilylation via a non-hydride pathway the ionic hydrogenation mechanism. The complete catalytic cycle is proposed to involve three steps: the formation of cis eta(1)-silane Re(V) adduct, the heterolytic cleavage of a Si-H bond through anti attack of carbonyls at the cis eta(1)-silane Re(V) adduct, and transfers between the rhenium and activated silylcarbonium ion to produce the silyl ether product and regenerate catalyst 1. The sigma-bond metathesis like transition state suggested by Abu-Omar, although not located, can be inferred from the ionic hydrogenation transition states (TS+3syn and TS_5syn, in which the carbonyls syn attack the eta(1)-silane Re(V) adduct) associated with the higher energy barrier.

• 出版日期2013-1-14
• 单位南京师范大学