[1,2]-Aryl migration in the synthesis of substituted indoles: scope, mechanism, and high throughput experimentation

A mild regioselective synthesis of substituted indoles from readily accessible 1-(2-aminophenyl)-2-chloroethanones is described. Addition of a range of carbon nucleophiles to α-chloro acetophenones 1 generates 2-substituted indoles 2 in moderate to excellent yields. A reaction mechanism involving a [1,2]-aryl migration is proposed. This useful transformation is further examined using high throughput experimentation.