Catalytic Enantioselective Friedel–Crafts Alkylation of Indoles with Nitroalkenes by Using a Simple Thiourea Organocatalyst

Abstract

A facile access to optically active 2-indolyl-1-nitro derivatives, which can be easily transformed into highly valuable compounds such as tryptamines and 1,2,3,4-tetrahydro-β-carbolines, is provided by the first catalytic enantioselective Friedel–Crafts alkylation of indoles with nitroalkenes (see scheme; e.g. R1=R2=H, R3=Ph).