An in situ formed palladium hydride catalyst enables the sequential dual isomerization of propargylamide derivatives to 1-amido-1,3-dienes with high chemo- and regioselectivity. The reaction shows ample functional group tolerance, delivering a valuable class of products, including highly deuterated ones, from readily available reagents. The reaction occurs through a complex mechanism studied by DFT
Axially Chiral Triazoloisoquinolin-3-ylidene Ligands in Gold(I)-Catalyzed Asymmetric Intermolecular (4 + 2) Cycloadditions of Allenamides and Dienes
作者:Javier Francos、Francisca Grande-Carmona、Hélio Faustino、Javier Iglesias-Sigüenza、Elena Díez、Isaac Alonso、Rosario Fernández、José M. Lassaletta、Fernando López、José L. Mascareñas
DOI:10.1021/ja3065446
日期:2012.9.5
The first highly enantioselective intermolecular (4 + 2) cycloaddition between allenes and dienes is reported. The reaction provides good yields of optically active cyclohexenes featuring diverse substitution patterns and up to three stereocenters. Key to the success of the process is the use of newly designed axially chiral N-heterocyclic carbene-gold catalysts.