Copper-catalysed asymmetric conjugate addition of organometallic reagents to linear enones using thiourethane ligands

Article abstract of DOI:10.1016/S0040-4039(98)02686-0

In the presence of chiral thiourethane ligands [Cu(MeCN)₄]BF₄ forms active catalysts for the conjugate addition of MeMgBr, ZnEt₂ and AlR₃ (R = Me, Et) to non-3-en-2-one, hept-3-en-2-one, and 5-methylhex-3-en-2-one. Enantioselectivities of up to 51% are realised for these difficult substrates; for cyclohex-2-enone an e.e. of 42% is attained.