N-Substituted Auxiliaries for Aerobic Dehydrogenation of Tetrahydro-isoquinoline: A Theory-Guided Photo-Catalytic Design.

ABSTRACT: Visible-light mediated aerobic dehydrogenation of N-heterocyclic compounds is a reaction with enormous potential for application. Herein, we report the first complete aerobic dehydrogenation pathway to large-scale production of isoquinolines. The discovery of this visible light photoredox reaction was enabled through the combination of mathematical simulations and real-time quantitative mass spectrometry screening. The theoretical calculations showed that hyper-conjugation, the main underlying factor hindering the aerobic oxidation of tetrahydroisoquinolines, is relieved both by π- and σ-donating substituents. This mechanistic insight provided a novel photocatalytic route based on N-substituted auxiliaries that facilitated the conversion of tetrahydroisoquinolines into the corresponding isoquinolines in just three simple steps (yield 71.7% in bulk-solution phase), using unmodified Ru(bpy)₃Cl₂ photocatalyst, sun energy, atmospheric O₂, and at ambient temperature.

SUBMITTER: Jayaraj S 

PROVIDER: S-EPMC6677888 | biostudies-literature | 2019 Aug

REPOSITORIES: biostudies-literature