Iridium-catalyzed Synthesis of Saturated N-Heterocycles from Aldehydes and SnAP Reagents with Continuous Flow Photochemistry.

Commercially available tin amine protocol (SnAP) reagents provide a simple approach to the synthesis of a wide variety of saturated N-heterocycles from aldehydes. In this report, we disclose that the copper(II) promoter and hexafluoroisopropanol can be replaced by photocatalytic conditions using Ir[dF(CF3)ppy]2(dtbbpy)PF6 in CH3CN. Continuous flow photochemical conditions provide a clean, scalable approach to valuable products including morpholines, piperazines, thiomorpholines, diazepanes, and oxazepanes from aldehyde starting materials.