Photoredox/Ti dual-catalyzed dehydroxylative ring-opening Giese reaction of cyclobutanone oximes

Visible-Light-Promoted Reduction of Epoxides, Hydroxysulfonates, and Halohydrines with Alkyltitanium Alkoxides

“…Being readily available and nontoxic, titanium reagents and catalysts have been employed in remarkably diverse organic transformations including oxidation, reduction, and C–C bond forming reactions. − Low valent titanium species, especially Ti III compounds, are powerful reducing agents capable of reacting with carbonyl, imine, oxime, epoxide, acylaziridine, halide, hydroxyl, oxazoline, and other functional groups (Scheme A). − These reagents are air-sensitive and typically prepared in situ by the reduction of an available Ti IV compound with a suitable reductant such as K, Zn, Mn, or Mg metals or a Grignard reagent. Recently, Ti III/IV catalysis was successfully merged with photoredox catalysis, where reduction of Ti IV was achieved by the oxidative quenching of a photocatalyst .…”