was suitable for bulkier substrates (sterictuning of the catalyst). Using the La-NMe-linked-BINOL complex, the Michaelreaction of methyl acetoacetate (8a) to 2-cyclohexen-1-one (7b) gave the corresponding Michael adduct 9ba in 82% yield and 92% ee. The linker heteroatom in linked-BINOL is crucial for achieving high reactivity and selectivity in the Michaelreaction of beta-keto esters. The amine moiety
Enantio- and diastereoselective construction of vicinal quaternary and tertiary carbon centers by catalytic Michael reaction of α-substituted β-keto esters to cyclic enones
A catalytic enantio- and diastereoselective Michael reaction was achieved to construct vicinal quaternary and tertiary carboncenters in one step. Using 5 mol % of La(O-i-Pr)3 and 10 mol % of a new N-linked-BINOL type ligand, the reaction of α-substituted β-ketoesters to cyclic enones provided the corresponding Michael adducts in up to quantitative yield with a diastereomeric ratio up to 86/14 and