Intercepting the Disilene‐Silylsilylene Equilibrium

The isomerization of disilene, Si₂H₄, to its silylsilylene tautomer occurs readily. Stable disilenes with bulky substituents display reactivity that indicates the same rearrangement can occur, but experimental observations of the silylsilylene isomers are rare. The base coordinated hydridodisilenes that rearrange to their silylsilylene isomers are reported, together with a detailed mechanistic study of the transformation.

Abstract

The equilibrium between disilenes (R₂Si=SiR₂) and their silylsilylene (R₃Si−SiR) isomers has previously been inferred but not directly observed, except in the case of the parent system H₂Si=SiH₂. Here, we report a new method to prepare base‐coordinated disilenes with hydride substituents. By varying the bulk of the coordinating base and other silicon substituents, we have been able to control the rearrangement of disilene adducts to their silylsilylene tautomers. Remarkably, 1,2 migration of a trimethylsilyl group is preferred over hydrogen migration. A DFT study of the reaction mechanism provides a rationale for the observed reactivity and detailed information on the bonding situation in base‐stabilized disilenes.

from A via a.sfakia on Inoreader http://bit.ly/2TnySek