2005 年 63 巻 9 号 p. 888-898
Enantioselective allylation of carbonyl compounds and aldol reaction are powerful and essential tools for synthesizing optically active homoallylic alcohols and β-hydroxy carbonyl compounds, respectively. We have found that BINAP·AgOTf complex is an excellent catalyst for asymmetric allylation of aldehydes with allyltributyltin as well as the asymmetric aldol synthesis of tributyltin enolates with aldehydes, and can furnish the corresponding nonracemic products with high diastereo- and enantioselectivities. These reactions are useful with respect to reactivity and selectivity. Later, we developed an alternative BINAP·AgOTf-catalyzed asymmetric aldol reaction of an alkenyl trichloroacetate employing a catalytic amount of trialkyltin methoxide. Asymmetric Sakurai-Hosomi allylation of aldehydes with allylic trimethoxysilanes and Mukaiyama-type aldol reaction of trimethoxysilyl enolates have been also achieved using BINAP·AgF as a chiral catalyst in methanol or using a mixture of BINAP·AgOTf and KF·18-crown-6 as bifunctional chiral cata-lysts in THF. BINAP·Ag (I) complexes are also known to catalyze enantioselective nitroso aldol reaction between trialkyltin enolates and nitrosobenzene.