Origins of opposite absolute stereoselectivities in proline-catalyzed direct Mannich and aldol reactions.
[structure: see text] The first computational studies to elucidate the stereoselectivity of the proline-catalyzed direct Mannich reaction have been performed using density functional theory (B3LYP/6-31G*). The transition states for the proline-catalyzed direct Mannich reaction of the proline enamine of acetone with the N-phenyl imine of acetaldehyde are reported here. The computed transition states provide a general model that explains the origin of the opposite stereoselectivities of proline-catalyzed Mannich and aldol reactions.
Bahmanyar
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Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095-1569, USA.
Houk
K N
KN
D000079:Acetaldehyde / Q000737:chemistry; D000447:Aldehydes / Q000737:chemistry*; D000588:Amines / Q000138:chemical synthesis* / Q000737:chemistry; D002384:Catalysis; D007097:Imines / Q000737:chemistry; D008352:Mannich Bases / Q000737:chemistry*; D008956:Models, Chemical; D008958:Models, Molecular; D011392:Proline / Q000737:chemistry*; D013237:Stereoisomerism
D000447:Aldehydes; D000588:Amines; D007097:Imines; D008352:Mannich Bases; D011392:Proline; D000079:Acetaldehyde