Redox-economical radical reactions by organic photoredox catalysis.

A photocatalytic hydroaminomethylation of olefins with N-protected aminomethyltrifluoroborates has been developed. This methodology provides a new strategy for the introduction of a primary aminomethyl group onto electron-deficient C=C bonds. This reaction constitutes a facile entry into synthetically useful g-aminobutyric acid (GABA) derivatives such as baclofen.

A simple and regiospecific aminohydroxylation of olefins by photoredox catalysis has been developed. N-protected 1-aminopyridinium salts are the key compounds and serve as amidyl radical precursors by the action of Ir photocatalysts, fac-[Ir(ppy)3] and [Ir(ppy)2 (dtbbpy)](PF6) (ppy=2-pyridylphenyl, dtbbpy=4,4'-di-tert-butyl-2,2'-bipyridine). The present photocatalytic system allows for synthesis of vicinal aminoalcohol derivatives from olefins with various functional groups under mild reaction conditions with easy handling.

Hydroalkoxymethylation of electron-deficient alkenes using alkoxymethyltrifluoroborates by photoredox catalysis has been developed. Highly reactive alkoxymethyl radicals can be easily generated from oxidation of alkoxymethyltrifluoroborates via a visible-light-induced SET process.