Redox-Photosensitized Reactions. XIV. Photochemistry of 4-Alkylated NADH Models, 1-Benzyl-4-(1-hydroxyalkyl)-1,4-dihydronicotinamides

Article abstract of DOI:10.1246/bcsj.60.1801

There were investigated photochemical behaviors of 4-alkylated 1-benzyl-1,4-dihydronicotinamides (1a-c) having R¹R²C(OH) as the substituent (a: R¹=Ph and R²=H; b: R¹=Ph and R²=CF3; c: R¹=p-NC-C6H4 and R²=H).The direct photolysis of 1a-c gave R¹R²CO and the dimers of the dihydronicotinamide (BNA) fragment along with a minor amount of 2, being thus interpreted in terms of the homolysis between the R¹R²(OH) and BNA moieties.In the ²⁺-photosensitized reactions, it is suggested that 1a-c^+. was generated as a key intermediate by electron transfer to excited ²⁺, undergoing a bond cleavage to give R¹R²CO and BNA^. dimers.In the case of 1c, however, R¹R²CH(OH) was formed, being attributed to a product from 1c^-. that is formed by electron transfer from ⁺ to 1c.