Photochemical addition of secondary alcohols to maleimides
作者:Muhammed A. S. Al-Amoudi、John M. Vernon
DOI:10.1039/a907517h
日期:——
Under UV irradiation, propan-2-ol adds to the CC bond of maleimides 4 to give 2-(1-hydroxy-1-methylethyl)succinimides 5 in 25–70% yield. Cyclohexanol adds in the same way to give 2-(1-hydroxycyclohexyl)succinimides 6. Several trace by-products are identified by GC-MS analysis and their formation accounted for.
Site-selectivity in C(sp3)–H functionalization of aliphatic alcohols and alkanes was studied using the decatungstate anion as a photocatalyst. In the case of aliphatic alcohols, C–H bond α to the hydroxy group was preferentially functionalized. The α-site-selectivity is rationalized by polar effects imparted by the hydroxy group in the SH2 transition states. In contrast, C–H functionalization of alkanes was largely affected by steric effects.