Access to Hexahydrocarbazoles: The Thorpe–Ingold Effects of the Ligand on Enantioselectivity. Issue 24 (11th May 2017) - Chen, Hao
Abstract: A novel cyclization reaction of methylenemalonate with indoles is reported, and it provides efficient access to a variety of hexahydrocarbazoles. The enantioselective version was realized by a finely tuned ligand/Cu II catalyst. The optically active hexahydrocarbazoles contain three quaternary carbon centers and are obtained in up to 99 % yield with greater than 99:1 d.r. and up to greater than 99 % ee. This reaction can be carried out on gram scale and stereoselective transformation of the product led to the core structure of a series of alkaloids from Kopsia plants. Abstract : Wing it : By using a newly designedWing‐BOX /Cu II catalyst, a cyclization reaction furnished optically active hexahydrocarbazoles, having three quaternary carbon centers and two carbon stereocenters, in up to 99 % yield with greater than 99:1 d.r. and up to greater than 99 % ee .