Selective Formation of Imines by Aerobic Photocatalytic Oxidation of Amines on TiO₂

Visible light mediated homo- and heterocoupling of benzyl alcohols and benzyl amines on polycrystalline cadmium sulfide

“…While the CdS photocatalytic cross-coupling reactions of benzyl alcohol and benzyl amine proceed with low selectivity (10) a 53% meso product and 36% rac. b Only meso diastereomer detected.…”

“…They have been applied to visible light water splitting, 5 reduction of nitrate to ammonia, 6 carbon dioxide activation, 7 hydrogen production, 8 oxidation of alcohols to aldehydes, 9 and amines to imines. 10 Photocatalytic C-C bond formations using heterogeneous photocatalysts are rare. A preparative example is the anaerobic dehydrodimerization of cyclic unsaturated ethers photocatalyzed by zinc or cadmium sulfides (Scheme 1).…”

Simple copper/TEMPO catalyzed aerobic dehydrogenation of benzylic amines and anilines

“…Very recently, Zhao et al reported the selective aerobic photocatalytic oxidation of amines to imines on TiO 2 . 17 However, many of these catalytic systems have limited substrate scope and are only active for secondary amines.…”

Factors affecting the selectivity of the photocatalytic conversion of nitroaromatic compounds over TiO2 to valuable nitrogen-containing organic compounds

“…This unique feature allows several transformations to be performed in one sequence without the necessity of the isolation of the intermediates. [4][5][6][7][8] Furthermore, these redox reactions by photogenerated electrons and holes do not produce by-products usually originating from the reductant or the oxidant; this is contrastive to conventional redox reagents such as permanganate or lithium aluminum hydride to leave, respectively, manganese ion or aluminum hydroxide after oxidation and reduction. Moreover, photocatalytic organic conversions can sometimes offer higher selectivities than conventional methods.…”