One-pot asymmetric synthesis of seven-membered carbocycles cyclohepta[b]indoles via a sequential organocatalytic Michael/double Friedel-Crafts alkylation reaction.

A new method has been developed for the enantioselective synthesis of highly functionalized cyclohepta[b]indoles with high enantioselectivity (up to 96% ee). The process combines an enantioselective organocatalytic Michael addition and a highly efficient double Friedel-Crafts reaction sequence in one pot with good yields and stereoselectivity. The structures and absolute configurations of the products were confirmed by X-ray analysis.