通过微波辅助聚磷酸乙酯(PPE)促进的ω-硫代酰胺醇的闭环反应,开发了一种高效且通用的合成2-取代的噻唑啉和5,6-二氢-4 H -1,3-噻嗪的方法。环化反应涉及S N 2型机理,具有反应时间短,产率高和可预测的立体化学结果的优点。无环前体是通过改进的二酰化-硫磺化-皂化顺序,从市售的ω-氨基醇中以高收率制备的。整个过程无金属且操作简单。
Microwave- and Photoirradiation-Induced Staudinger Reactions of Cyclic Imines and Ketenes Generated from α-Diazoketones. A Further Investigation into the Stereochemical Process
作者:Yong Liang、Lei Jiao、Shiwei Zhang、Jiaxi Xu
DOI:10.1021/jo048328o
日期:2005.1.1
with a series of acyclic and cyclicimines were investigated under both microwave and photoirradiation conditions. The results indicate that the zwitterionic azabutadiene-type intermediates yielded from imines and ketenes undergo a conrotatory ring closure exclusively to produce β-lactams. It is notable that no Woodward−Hoffmann product was found under the ultraviolet irradiation. The photoirradiation-induced
Intramolecular allyl, benzyl or methylene ester transfer is observed upon treatment of suitably functionalized 1,3-thiazanes with catalytic amounts of either anhydrous iridium trichloride or chlorotricarbonyliridium in benzene under a carbon monoxide atmosphere (e.g. N-allyl-2-phenyl-1,3-thiazane is converted to N,S-diallyl-N-benzyl-1,3-aminothiol; the allyl unit is provided by a second molecule of the thiazane, which is in turn converted into the corresponding thiazine by formal loss of propene).