Development towards stable silver(I) catalysts

Abstract

The use of silver(I) compounds as catalysts for organic transformations has been earning a growing interest. Compared to most of the transition metal catalysts, silver(I) compounds are relatively inexpensive and these catalysts function well under mild reaction conditions. However, compare to the analogous gold catalysis, reports on silver(I) catalysis remains sparse, possibly due to their strong oxidizing power and light-instability. Therefore, by improving the stability of silver catalysts with the incorporation of suitable ligands, we envision that silver catalysts have the potential to gain the same achievement as its powerful gold counterpart in a cost-effective way. Here we report the Diels-Alder reaction of axially chiral vinylallenes as the diene component in the presence of stable heterogeneous silver(I) catalyst [Ag(PPh3)3Br], giving complex cycloadducts in good to excellent yields (up to 92%) with excellent axial-to-point chirality transfer (up to 97% ee).