Radical Cyclizations of Alkenyl Acylphosphonate Derivatives under Thermal and Photochemical Conditions
作者:Chang Ho Cho、Sunggak Kim、Motoki Yamane、Hironori Miyauchi、Koichi Narasaka
DOI:10.1246/bcsj.78.1665
日期:2005.9
The use of alkenyl acylphosphonate and acylphosphine oxide derivatives as acceptors in radical cyclizations was studied under thermal and photochemical conditions, respectively. The cyclizations of alkenyl acylphosphonates under thermal conditions occurred smoothly in refluxing dioxane using benzoyl peroxide as an initiator; the addition of diethyl phosphite increased the chemical yield. Photochemically induced cyclizations of alkenyl acyldiphenylphosphine oxides at 300 nm gave similar results, although a notable difference was observed in one case. The intramolecular cyclization of S-but-3-enyl phosphinothiolformates occurred under thermal and photochemical conditions, providing thiolactones, whereas S-pent-4-enyl phosphinothiolformate afforded the tetrahydrothiophene derivative under similar conditions.
在热和光化学条件下,分别研究了烯丙基酰基膦酸酯和酰基膋氧化物衍生物作为受体在自由基环合反应中的应用。热条件下烯丙基酰基膦酸酯的环合反应在回流的二恶烷中顺利进行,以苯甲酰过氧化物为引发剂;加入亚磷酸二乙酯可提高化学产率。在300 nm光化学诱导下,烯丙基酰基二苯基膦氧化物的环合反应得到类似结果,尽管在一个案例中观察到了显著差异。在热和光化学条件下,S-丁-3-烯基膦硫酯的内环化反应提供了硫酯,而S-戊-4-烯基膦硫酯在类似条件下生成了四氢噻吩衍生物。