Recent trends in catalytic sp3 C–H functionalization of heterocycles

Abstract

Heterocycles are a ubiquitous substructure in organic small molecules designed for use in materials and medicines. Recent work in catalysis has focused on enabling access to new heterocycle structures by sp³ C–H functionalization on alkyl side-chain substituents—especially at the heterobenzylic position—with more than two hundred manuscripts published just within the last ten years. Rather than describing in detail each of these reports, in this mini-review we attempt to highlight gaps in existing techniques. A semi-quantitative overview of ongoing work strongly suggests that several specific heterocycle types and bond formations outside of C–C, C–N, and C–O have been almost completely overlooked.