Direct Conversion of Primary Alcohols to 1,2-Amino Alcohols: Enantioselective Iridium-Catalyzed Carbonyl Reductive Coupling of Phthalimido-Allene via Hydrogen Auto-Transfer

摘要

The first catalytic enantioselective carbonyl (alpha-amino)allylations are described. Phthalimido-allene 1 and primary alcohols 2a-2z, 2a'-2c' engage in hydrogen auto-transfer-mediated carbonyl reductive coupling by way of (alpha-amino)allyliridium-aldehyde pairs to form vicinal amino alcohols 3a-3z, 3a'-3c' with high levels of regio-, anti-diastereo-, and enantioselectivity. Reaction progress kinetic analysis and isotopic labeling studies corroborate a catalytic cycle involving turnover-limiting alcohol dehydrogenation followed by rapid allene hydrometalation.