Enantioselective synthesis of cyclopenta[b]benzofurans via an organocatalytic intramolecular double cyclization.

ABSTRACT: An enantioselective organocatalytic strategy, combining Brønsted base and N-heterocyclic carbene catalysis in a unique manner, is demonstrated for a concise construction of the privileged cyclopenta[b]benzofuran scaffold, present in many bioactive compounds having both academic and commercial interests. The reaction concept relies on an intramolecular one-pot double cyclization involving a cycle-specific enantioselective Michael addition followed by a benzoin condensation of ortho-substituted cinnamaldehydes. Cyclopenta[b]benzofurans were achieved in moderate to good yields, with excellent stereoselectivities. A proof of principle for a diastereodivergent variation is demonstrated through the synthesis of cyclopenta[b]benzofurans containing two contiguous aromat

SUBMITTER: Paz BM 

PROVIDER: S-EPMC5855134 | biostudies-literature | 2017 Dec

REPOSITORIES: biostudies-literature