Synthesis and Catalytic Activity of 1,2,4,3-Triazaphospholenes

Abstract

Catalysis plays a key role in the industrial production of many refined goods. Catalysts derived from precious metals are especially prevalent in industry due to their high stereoselectivity, and low loadings. To alleviate the reliance on precious metals, catalysts derived from cheaper, more abundant main group elements have attracted much attention in recent years. 1,3,2-Diazaphospholenes developed by Gudat, Kinjo, and our group have shown great potential in the reduction of various unsaturated carbons including imines, carbonyls, olefins, etc. In an effort to uncover catalytic activity in more elaborate heterocycles, I have developed a new class of hydroboration catalysts, namely 1,2,4,3-triazaphospholenes. The synthesis towards 1,2,4,3-triazaphospholenes and their reactivity in the racemic and non-racemic hydroboration of imines and carbonyls are disclosed herein.