Expedient synthesis of densely substituted pyrrolo[1,2-a]indoles

Abstract

Cu(OTf)₂ catalyzed [6 + 2] cycloaddition reaction of indolyl-2-carbinols with various dienophiles such as indole derived α,β-unsaturated esters, ketones, nitriles and cinnamates is described. The strategy was further applied for the synthesis of optically active pyrrolo[1,2-a]indoles in >97% de using the chiral auxiliary based approach.