Asymmetric H_2O-Nucleophilic Ring Opening of D-A Cydopropanes: Catalyst Serves as a Source of Water

摘要

The first catalytic enantioselective ring-opening reaction of donor-acceptor cydopropanes with water is described. By employing Cy-TOX/Cu(Ⅱ) as catalyst, the reaction performed very well over a broad range of substrates, leading to the ring-opening products in 70-96% yields with up to 95% ee under mild conditions. The current method provides a new approach to direct access to γ-substituted GBH derivatives very efficiently. Importantly, Cu(ClO_4)_2·6H_2O proves to serve as both a Lewis add and a source of water, which affords a fine system to controllably release water as a nudeophile in the asymmetric catalysis.