Rhodium-catalyzed reductive mannich coupling of vinyl ketones to N-sulfonylimines mediated by hydrogen.
Catalytic hydrogenation of methyl vinyl ketone (MVK) and ethyl vinyl ketone (EVK) in the presence of N-(o-nitrophenylsulfonyl)imines 8a-13a at ambient pressure with tri-2-furylphosphine-ligated rhodium catalysts enables formation of Mannich products 8b-13b and 8c-13c with moderate to good levels of syn-diastereoselectivity. As revealed by an assay of various N-protecting groups, excellent yields of reductive Mannich product also are obtained for N-arylimines 1a-4a, although diminished levels of syn-diastereoselectivity are observed. Coupling of MVK to imine 8a under a deuterium atmosphere provides deuterio-8b, which incorporates a single deuterium atom at the former enone beta-position.
Garner
Susan A
SA
Department of Chemistry and Biochemistry, University of Texas at Austin, 1 University Station A5300, Austin, TX 78712-1167, USA.
Krische
Michael J
MJ
D002384:Catalysis; D006859:Hydrogen / Q000737:chemistry*; D007097:Imines / Q000737:chemistry*; D007659:Ketones / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D010084:Oxidation-Reduction; D012238:Rhodium / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D013450:Sulfones / Q000737:chemistry*
D007097:Imines; D007659:Ketones; C482356:N-sulfonylimine; D013450:Sulfones; D006859:Hydrogen; D012238:Rhodium