High enantiocontrol in the intramolecular cyclopropanation of diazo ketones catalyzed by dirhodium(II) complexes with ortho-metalated aryl phosphine ligands.
[reaction: see text]. Chiral dirhodium(II) complexes, Rh2(O2CCF3)2(PC)2, [PCH = (p-CH3C6H4)3P, (m-CH3C6H4)3P], provide an excellent yield and a high enantiocontrol in the cyclopropanation of alpha-diazo ketones with gamma and delta double bonds. The ee values are significantly dependent on the solvent used; the best results are obtained using pentane.
Barberis
M
M
Departamento de Química Orgánica/Instituto de Ciencia Molecular, Facultad de Farmacia, Universidad de Valencia, 46100 Burjassot, Valencia.
Pérez-Prieto
J
J
Stiriba
S E
SE
Lahuerta
P
P