Development of multiactive site catalysts for surface concerted catalysis aimed at one-pot synthesis

Abstract

Multiactive site catalysts have been developed for conducting one-pot synthesis and highly efficient reactions based on the principle of concerted catalysis. Ru-grafted hydrotalcite containing both Ru and base sites on its outer surface exhibits high catalytic activity for the one-pot synthesis of dinitrile compounds. A reaction system consisting of a strong acid, base, and Pd species is capable of catalyzing a one-pot process consisting of five successive reactions, esterification, deacetalization, aldol reaction, hydrogenation, and Michael reaction, to produce a final product, 2,4-dicyanoester, from starting materials containing cycnoacetic acid and acetal, with excellent overall yield. Immobilization of an amine base onto a solid acid surface affords an acidbase bifunctional catalytic surface with controlled acidbase interactions. Various nucleophilic addition reactions including the one-pot synthesis of dinitroalkane derivatives proceeds effectively by acidbase concerted catalysis. The concept of concerted catalysis on solid surfaces can be extended to synergistic/double-activation catalysis between a metal complex and organic base immobilized on a surface. Further, the concept of multiactive site catalysis can also be applied to a homogeneous catalyst system. For example, a Cu-bisphosphine complex exhibits excellent catalytic performance for the transformation of CO2 to valuable chemicals, such as cyclic carbonate, silyl formate, and formamides.