In Situ Generation of Nucleophilic Allenes by the Gold-Catalyzed Rearrangement of Propargylic Esters for the Highly Diastereoselective Formation of Intermolecular C(sp~3)-C(sp~2) Bonds

摘要

In the last few years, in the field of homogeneous gold catalysis rearrangement reactions involving propargylic esters have received considerable attention owing to the synthetic utility of these easily accessible compounds in a wide variety of intriguing, fascinating transformations. It is established that in gold catalysis these propargylic esters can undergo 1,2-or 1,3-acyloxy migration leading to a gold vinyl carbenoid species or a gold allenic intermediate (Scheme 1), which can be further trapped by other functional groups to allow the synthesis of diverse organic products. The gold vinyl carbenoid species can undergo prototypical reactions, for example the cyclopropanation of alkenes and dienes, as well as insertion into C-H bonds. For the gold allenic intermediate, most studies cover intramolecular electrophilic addition reactions.