Copper-catalyzed (4+3)-cycloaddition of 4-indolylcarbinols with aziridines: stereoselective synthesis of azepinoindoles

A Cu( i )-catalysed (4+3)-cycloaddition has been presented for obtaining azepino[ c , d ]indole motifs in good yields. The reaction follows a stereoselective pathway, and optically pure azepinoindoles could be synthesised in up to 96% ee.