Lewis Base Catalysis: Reaction Development and Heterocycle Synthesis

Lewis base-mediated reactions encompass a plethora of molecular transformations. Within this area, we have developed a range of catalytic (asymmetric) processes mediated by a range of Lewis bases.¹ This presentation will describe recent developments in the use of isothioureas to promote a number of selective transformations that involve the generation of either an acyl ammonium,² ammonium enolate,³ a,b-unsaturated acyl ammonium⁴ or ylide intermediate⁵ (Figure 1). The application of these methodologies to the (enantioselective) synthesis of a variety of heterocyclic products, as well as mechanistic insights into these processes will be discussed.

Figure 1: Isothioureas and intermediates in enantioselective Lewis base catalysis