Ligand Bite Angle-Dependent Palladium-Catalyzed Cyclization of Propargylic Carbonates to 2-Alkynyl Azacycles or Cyclic Dienamides
作者:David S. B. Daniels、Alison S. Jones、Amber L. Thompson、Robert S. Paton、Edward A. Anderson
DOI:10.1002/anie.201309162
日期:2014.2.10
palladium‐catalyzed cyclization of propargyliccarbonates with sulfonamide nucleophiles is critically dependent on the bite angle of the bidentate phosphine ligand. Ligands with small bite angles favor attack on the central carbon atom of an allenylpalladium intermediate to afford cyclicdienamide products, whereas the use of those with large bite angles leads to alkynyl azacycles, with high stereoselectivity