Iodine monobromide catalysed regioselective synthesis of 3-arylquinolines from α-aminoacetophenones and trans-ß-nitrostyrenes.

A simple and efficient method for regioselective synthesis of 3-arylquinolines is described from α-aminoacetophenones and trans-ß-nitrostyrenes using 20 mol% iodine monobromide as a catalyst in acetonitrile solvent at 80 °C. The present method involves tandem reaction of α-aminoacetophenones and trans-ß-nitrostyrenes, formation of two new C-C bonds and cleavage of one C-C bond in a single step. The salient features of the protocol are metal- and oxidant-free reaction conditions, broad substrate scope, and good yields.