ENANTIOSELECTIVE CONJUGATE ADDITION TO CYCLIC ENONES WITH (S)-MAPP-CUPRATES
Chiral amidocuprates, formed from CuI, n-butyl or methyl lithium and (S)-N-methyl-1-phenyl-2-(1-piperidinyl)ethanamine, (S)-MAPP, react enantioselectively with 5, 6, 7 and 8-membered cyclic enones to give products with up to 97percent e.e.The synthesis of (S)-MAPP is also reported.
Enantioselective conjugate addition to cyclic enones with scalemic lithium organo(amido)cuprates, part IV. Relationship between ligand structure and enantioselectivity
Scalemic lithium amides derived from primary and secondary amines react with organocopper compounds in ether or dimethyl sulfide to form lithium organo(amido)cuprates capable of enantioselective conjugate addition to 2-cycloalkenones. The most successful heterocuprate, in which the chiral ligand is (S)-N-methyl-1-phenyl-2-(1-piperidinyl)ethanamine, (S)-MAPP, 13, reacts with cyclic enones to form products with up to 97% ee. Nonlinear asymmetric induction was observed with the cuprate formed from ligand 13.