Asymmetric Synthesis of N- and O-Heterocycles Using Sequential Ru-Pd Catalysis

Significance

A sequential, two-catalyst process for the asymmetric synthesis of 5-, 6-, and 7-membered N- or O-heterocycles with high regio- and stereoselectivity is reported. The thermodynamically disfavored trans diastereomers may be obtained using both R,R and S,S ligands. The practical utility of this methodology was demonstrated by the highly efficient synthesis of the ring B fragment previously used for the construction of the potent anticancer bryostatin natural products.