Non‐Ionic Peterson‐type Olefination Reactivity and its Use in a Silicon‐promoted Carbonyl‐Carbonyl Cross Coupling Reaction

Abstract

The [2+2] cycloaddition reaction between the Si=C double bond of adamantylsilene and the carbonyl group of aliphatic, aromatic or acetylenic ketones and aldehydes is demonstrated. The product of this reaction that is central to a non‐ionic version of the Peterson olefination is an unusual four‐membered 1,2‐silaoxetane heterocycle that was characterized spectroscopically and crystallographically. In the presence of SiO2, the silaoxetane undergoes retro‐cycloaddition with the formation of alkene products. As the [2+2] cycloaddition proceeds without the necessity of any base, enolizable ketones can be converted into olefins. In addition, it is shown that the adamantylsilene can be produced in situ by a sila‐Peterson reaction, providing valuable input for the development of a new one‐pot silicon‐based reductive carbonyl‐carbonyl cross coupling methodology.