Aggregation-Induced Catalysis: Asymmetric Catalysis with Chiral Aggregates

So far,there have been 4 methods to control chirality including the use of chiral auxiliaries,reagents,solvents,and catalysts documented in literature and textbooks.Among them,asymmetric catalysts are normally divided into homogeneous and heterogeneous catalysis.In this report,we present a new type of asymmetric control—asymmetric catalysis via chiral aggregates that would not belong to the above categories.This new strategy is represented by catalytic asymmetric dihydroxylation reaction of olefins in which chiral ligands are aggregated by taking advantage of typical aggregation-induced emission systems containing tetrahydrofuran and H_(2)O cosolvents.It was proven that the chiral induction can be enhanced from er of 78:22 to 97:3 simply by changing the ratios of these 2 cosolvents.