Isoquinolines are ubiquitous arenes found in many biologically useful molecules. While direct substitution at the heterocyclic ring is uncommon, reductive functionalization to form tetrahydroisoquinolines (THIQs) is straightforward. Herein, we describe a facile method for producing C4-functionalized isoquinolines from a readily available parent THIQ. This high-temperature transformation utilizes pyridine-N-oxide as an oxidant generating only volatile side products and is functional-group-tolerant.
