A chiral titanium complex 1a derived from 6,6'-dibromo-1,1'-bi-2-naphthol is found to give higher endo- and enantioselectivity along with higher catalytic activity than the parent binaphthol-derived titanium complex 1b in the (hetero) Diels-Alder reactions of 1-methoxydienes (2a and 2c) with methacrolein and glyoxylate but not with bromoacrolein.
- (hetero) Diels-Alder reaction
- asymmetric catalysis
- Lewis acid
- titanium complex