One-Pot Catalytic Asymmetric Synthesis of Tetrahydrocarbazoles
摘要:
A one-pot asymmetric synthesis of 1,2,3,4-tetrahydrocarbizoles has been developed via an enantioselective [3 + 3] annulation of 2-alkynylindoles and donor acceptor cyclopropanes. In the presence of chiral Lewis acids as catalysts, a series of optically active tetrahydrocarbazoles were furnished in high yields (63-87%) With good to excellent levels of enantioselectivity (up to 94% ee).
Tandem Cyclopropane Ring-Opening/Conia-ene Reactions of 2-Alkynyl Indoles: A [3 + 3] Annulative Route to Tetrahydrocarbazoles
作者:Huck K. Grover、Terry P. Lebold、Michael A. Kerr
DOI:10.1021/ol102627e
日期:2011.1.21
A Zn(NTf2)2catalyzed tandem reaction consisting of a nucelophilic ringopening of 1,1-cyclopropanediesters by 2-alkynyl indoles followed by a Conia-ene ring closure results in the efficient one-step synthesis of tetrahydrocarbazoles. The adducts may be further elaborated to carbazoles.