An easy route toward enantio-enriched polycyclic derivatives via an asymmetric domino conjugate reduction-aldol cyclization catalyzed by a chiral Cu(I) complex

A highly efficient reductive-aldol cyclization mediated by a chiral Cu(I) complex and an organosilane yielded to cyclic or polycyclic derivatives. An excellent control of the selectivities was reached in most cases (dr up to 100:0 and ee up to 95%). After developing the enantioselective intramolecular reductive-aldol methodology, this strategy was successfully used for the synthesis of a key intermediate of a natural diterpene in few steps. (C) 2011 Elsevier Ltd. All rights reserved.