Photoreactions of 3-Diazo-3<i>H</i>-benzofuran-2-one; Dimerization and Hydrolysis of Its Primary Photoproduct, A Quinonoid Cumulenone: A Study by Time-Resolved Optical and Infrared Spectroscopy
作者:Yvonne Chiang、Martin Gaplovsky、A. Jerry Kresge、King Hung Leung、Christian Ley、Marek Mac、Gabriele Persy、David L. Phillips、Vladimir V. Popik、Christoph Rödig、Jakob Wirz、Yu Zhu
DOI:10.1021/ja0365476
日期:2003.10.1
nanosecond flash photolysis with optical (lambda(max) approximately 460 nm) as well as Raman (1526 cm(-1)) and IR detection (2050 cm(-)(1)). Remarkably, the reactivity of 3 is that expected from its valence isomer, the cyclic carbene 3H-benzofuran-2-one-3-ylidene, 2. In aqueous solution, acid-catalyzed addition of water forms the lactone 3-hydroxy-3H-benzofuran-2-one (5). The reaction is initiated by protonation
溶液中 3-diazo-3H-benzofuran-2-one (1) 的光诱导脱氮伴随着简单的 (CO)-O 键裂解,产生 6-(oxoehenylidene)-2,4-cyclohexadien-1-one (3 ),其上升时间为 28 ps。未形成预期的 Wolff 重排产物 7-oxabicyclo[4.2.0]octa-1,3,5-trien-8-ylidenemethanone (4)。醌类cumulenone 3 的有效光诱导形成为确定溶液中的cumulenone 的反应性开辟了道路。3 的反应动力学由纳秒闪光光解与光学 (λ(max) 约 460 nm) 以及拉曼 (1526 cm(-1)) 和红外检测 (2050 cm(-)(1)) 监测。值得注意的是,3 的反应性是其价异构体,环状卡宾 3H-苯并呋喃-2-one-3-ylidene,2 预期的反应性。在水溶液中,水的酸催化加成形成内酯