Continuous Flow Synthesis of Morpholines and Oxazepanes with Silicon Amine Protocol (SLAP) Reagents and Lewis Acid Facilitated Photoredox Catalysis

Photocatalytic
coupling of aldehydes and silicon amine protocol (SLAP) reagents enables
the simple, scalable synthesis of substituted morpholines, oxazepanes,
thiomorpholines, and thiazepanes under continuous flow conditions.
Key to the success of this process is the combination of an inexpensive
organic photocatalyst (TPP) and a Lewis acid additive, which form
an amine radical cation that is easily reduced to complete the catalytic
cycle. Di- and trisubstituted SLAP reagents are formed in one step
by an iron-catalyzed aminoetherification of olefins.