Cu-Catalyzed Aerobic Oxidative Three-Component Coupling Route to N-Sulfonyl Amidines via an Ynamine Intermediate
Jinho Kim and Shannon S. Stahl*
*Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States, Email: stahlchem.wisc.edu
J. Kim, S. S. Stahl, J. Org. Chem., 2015, 80, 2448-2454.
DOI: 10.1021/jo5029198 (free Supporting Information)
see article for more reactions
Cu-catalyzed aerobic oxidative three-component coupling of a terminal alkyne, secondary amine, and sulfonamide enables an efficient synthesis of amidines. The use of Cu(OTf)2 as catalyst produces amidines selectively via an initial oxidative coupling of the terminal alkyne with the secondary amine, followed by hydroamidation of the ynamine intermediate with the sulfonamide. Glaser-Hay alkyne homocoupling products are not observed.
see article for more examples