Highly enantioselective copper(I)-catalyzed conjugate addition of 1,3-diynes to α,β-unsaturated trifluoromethyl ketones.
The conjugate diynylation of α,β-unsaturated trifluoromethyl ketones is carried out in the presence of a low catalytic load (2.5 mol%) of a copper(I)-MeOBIPHEP complex, triethylamine and a terminal 1,3-diyne. Pre-metalation of the terminal 1,3-diyne with stoichiometric or higher amounts of dialkylzinc reagent is not required. The corresponding internal diynes bearing a propargylic stereogenic center are obtained with good yields and excellent enantioselectivities.
Departament de Química Orgànica, Facultat de Química, Universitat de València, C/Dr. Moliner 50, 46100-Burjassot, Spain. jose.r.pedro@uv.es gonzalo.blay@uv.es.
Amparo
A
Sanz-Marco
Gonzalo
G
Blay
M Carmen
MC
Muñoz
José R
JR
Pedro