The direct and enantioselective organocatalytic alpha-oxidation of aldehydes.
The first direct enantioselective catalytic alpha-oxidation of carbonyls has been accomplished. The use of enamine catalysis has provided a new organocatalytic strategy for the enantioselective oxyamination of aldehydes, to generate alpha-oxyaldehydes, important chiral synthons for natural product and medicinal agent synthesis. The use of l-proline as the asymmetric catalyst has been found to mediate the oxidation of a large variety of aldehyde substrates with nitrosobenzene serving as the electrophilic oxidant. A diverse spectrum of aldehyde substrates can also be accommodated in this new organocatalytic transformation. While catalyst quantities of 2 mol % were generally employed in this study, successful oxidations conducted using catalyst loadings as low as 0.5 mol % are described.
Brown
Sean P
SP
Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, USA.
Brochu
Michael P
MP
Sinz
Christopher J
CJ
MacMillan
David W C
DW
D000447:Aldehydes / Q000737:chemistry*; D000586:Amination; D000605:Amino Alcohols / Q000138:chemical synthesis; D010084:Oxidation-Reduction; D011392:Proline / Q000737:chemistry*; D013237:Stereoisomerism
D000447:Aldehydes; D000605:Amino Alcohols; D011392:Proline