Enantioselective organocatalytic hydride reduction.
The first enantioselective organocatalytic hydride reduction has been accomplished. The use of iminium catalysis has provided a new organocatalytic strategy for the enantioselective reduction of beta,beta-substituted alpha,beta-unsaturated aldehydes to generate beta-stereogenic aldehydes. The use of imidazolidinone 2 as the asymmetric catalyst has been found to mediate the transfer of hydrogen to a large class of enal substrates from ethyl Hantzsch ester. The capacity of catalyst 2 to accelerate E-Z isomerization prior to selective E-olefin reduction allows the implementation of geometrically impure enals in this operationally simple protocol.
Ouellet
Stéphane G
SG
Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, USA.
Tuttle
Jamison B
JB
MacMillan
David W C
DW
D000447:Aldehydes / Q000737:chemistry*; D004095:Dihydropyridines / Q000737:chemistry*; D006859:Hydrogen / Q000737:chemistry*; D048289:Imidazolidines / Q000737:chemistry*; D007097:Imines / Q000737:chemistry; D008958:Models, Molecular; D010084:Oxidation-Reduction; D011392:Proline / Q000737:chemistry; D013237:Stereoisomerism
D000447:Aldehydes; D004095:Dihydropyridines; D048289:Imidazolidines; D007097:Imines; D006859:Hydrogen; D011392:Proline