Arylboron Addition-Cyclization of Cyano-Substituted Unsaturated Esters

Significance

The article describes an interesting cascade-type cyclization reaction that gives rise to useful carbocyclic enamines. This method allows the construction of new annelated five- and six-membered cycles as well as the formation of cyclic enamines from acyclic α,β-unsaturated esters. The products can be transformed into various carbo- and heterocyclic compounds. The use of chiral ligands for rhodium catalysis derives a highly enantioselective process.