Asymmetric hetero-Diels-Alder reaction catalyzed by dirhodium(II) carboxamidates.
Chiral dirhodium(II) carboxamidates are highly efficient catalysts for reactions between a variety of aldehydes and activated dienes. Catalyst loadings as low at 0.01 mol % have been realized with enantioselectivities up to 97%. Kinetic investigations reveal a pronounced electronic influence on the rate of the hetero-Diels-Alder reaction with a Hammett rho value of +1.9 (versus sigma(+)). Inhibition of the catalyst by reactant aldehyde is apparent, but reactions show first-order dependence on aldehyde and diene, and there is a variable dependence on catalyst.
Doyle
Michael P
MP
Department of Chemistry and Biochemistry, University of Maryland, College Park, MD 20742, USA. mdoyle3@umd.edu
Valenzuela
Marcela
M
Huang
Penglin
P
D000447:Aldehydes / Q000737:chemistry*; D000475:Alkenes / Q000737:chemistry*; D002384:Catalysis; D003500:Cyclization; D006841:Hydrocarbons, Aromatic / Q000737:chemistry; D007700:Kinetics; D009942:Organometallic Compounds / Q000737:chemistry*; D012238:Rhodium / Q000737:chemistry*; D013237:Stereoisomerism
D000447:Aldehydes; D000475:Alkenes; D006841:Hydrocarbons, Aromatic; D009942:Organometallic Compounds; D012238:Rhodium