Photochemical reactions of mercapto/amino substituted alkyl phenylglyoxylates induced by intramolecular electron transfer
作者:Shengkui Hu、Douglas C. Neckers
DOI:10.1016/s0040-4020(97)00044-6
日期:1997.2
normal Norrish type II cleavage products, the title compounds undergo intermolecular electron transfer from the heteroatom (sulfur/nitrogen) to the excited carbonyl group, followed by proton transfer and subsequent closing of the resulting biradicals to produce seven-membered (2)/five-membered (11) lactones in high yield. Thiadialkyl phenylglyoxylates (9) react inefficiently due to intramolecular self-quenching
合成了2'-烷硫基乙基苯乙醛酸酯(1)和2'-二甲基氨基乙基苯乙醛酸酯(10),并对其光化学进行了研究。与提供正常的Norrish II型裂解产物的氧类似物3相比,标题化合物经历了从杂原子(硫/氮)到激发的羰基的分子间电子转移,随后进行了质子转移,随后将所得双自由基封闭为以高收率生产七元(2)/五元(11)内酯。噻二烷基苯基乙醛酸酯(9)由于苯基乙醛酸酯生色团的分子内自猝灭而反应无效。α-氧代硫酯的光反应性(将图14)与其氮(α-氧代酰胺)和氧(苯乙醛酸酯)的对应物进行比较。