Diarylborinic Acid Derivatives as a Catalytic Iminium Ion Generator in the Mannich-Type Reaction Using Secondary Amines, Aldehydes, and Ketene Silyl Acetals
Yusuke Tanaka, Tomoaki Hasui, Michinori Suginome*
*Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Kyoto 615-8510, Japan, Email: suginomesbchem.kyoto-u.ac.jp
Y. Tanaka, T. Hasui, M. Suginome, Synlett, 2008, 1239-1241.
DOI: 10.1055/s-2008-1072724
Abstract
Mannich-rype reactions of secondary amines, aldehydes and ketene silyl acetals were efficiently promoted by catalytic amounts of diarylborinic acid esters, affording β-amino esters selectively with no formation of the corresponding β-hydroxy esters.
see article for more examples
Aminoboranes as "Compatible" Iminium Ion Generators in Aminative C-C Bond Formations
M. Suginome, L. Uehlin, M. Murakami, J. Am. Chem. Soc., 2004, 126, 13196-13197.
Key Words
boron-based catalyst, β-amino acids, iminium ion intermediate, ketene silyl acetal, nucleophilic additions, Mannich Reaction, multicomponent reactions
ID: J60-Y2008-1150