Diastereo- and enantioselective anti-alkoxyallylation employing allylic gem-dicarboxylates as allyl donors via iridium-catalyzed transfer hydrogenation.
Enantioselective transfer hydrogenation of gem-dibenzoate 1e in the presence of aromatic, alpha,beta-unsaturated, or aliphatic aldehydes 2a-i mediated by isopropyl alcohol and employing a cyclometalated iridium C,O-benzoate derived from allyl acetate, 4-cyano-3-nitrobenzoic acid, and (R)-SEGPHOS delivers products of alkoxyallylation 3a-i, 4a, 4e, 4f, and 4i in good isolated yields (62-82%) with good to excellent diastereoselectivities (7:1 to 18:1 dr) and exceptional enantioselectivities (90-99% ee). This protocol provides an alternative to the use of premetalated nucleophiles in carbonyl alkoxyallylation.
Han
Soo Bong
SB
Department of Chemistry and Biochemistry, University of Texas at Austin, Austin, Texas 78712, USA.
Han
Hoon
H
Krische
Michael J
MJ
D000085:Acetates / Q000737:chemistry; D000447:Aldehydes / Q000737:chemistry; D000475:Alkenes / Q000737:chemistry*; D019817:Benzoic Acid / Q000737:chemistry; D002264:Carboxylic Acids / Q000737:chemistry*; D002384:Catalysis; D006865:Hydrogenation; D007495:Iridium / Q000737:chemistry*; D010084:Oxidation-Reduction; D010720:Phosphines / Q000737:chemistry; D013237:Stereoisomerism; D013379:Substrate Specificity
D000085:Acetates; D000447:Aldehydes; D000475:Alkenes; D002264:Carboxylic Acids; D010720:Phosphines; D007495:Iridium; D019817:Benzoic Acid; C044646:phosphine