A Zinc(II) Catalyst System for the Conia-Ene Reaction of Alkynyl-Aminomalonates Applicable to 5-Endo-Dig Reactions
作者:Wilfried Hess、Jonathan W. Burton
DOI:10.1002/adsc.201100401
日期:2011.11
The zinc(II)-catalyzed 5-exo-dig (Conia-ene) and 5-endo-dig cyclizations of a range of alkynyl-α-aminomalonates give rise to nitrogen heterocycles with good efficiency. The reaction allows the synthesis of a broad range of synthetically useful building blocks.
An original multi-cooperative catalytic approach was developed by combining metal–ligandcooperation and Lewis acidactivation. The [(SCS)Pd]2 complex featuring a non-innocent indenediide-based ligand was found to be a very efficient and versatilecatalyst for the Conia-ene reaction, when associated with Mg(OTf)2. The reaction operates at low catalytic loadings under mild conditions with HFIP as a