Radical-mediated reduction of the dithiocarbamate group under tin-free conditions
作者:Claire McMaster、Robert N. Bream、Richard S. Grainger
DOI:10.1039/c2ob25434d
日期:——
desulfurisation of dithiocarbamates is conveniently achieved using H3PO2–Et3N–ACCN in refluxing dioxane. Fused and spirocyclic β-lactams, prepared through 4-exo trig carbamoyl radical cyclisation–dithiocarbamate group transfer reactions, are reduced without fragmentation of the strained 4-membered ring. Diethyl tetraacetyl-D-glucopyranosyl dithiocarbamate is selectively reduced with or without acyloxy group migration
使用H 3 PO 2 -Et 3 N-ACCN在回流中方便地实现二硫代氨基甲酸酯的还原脱硫二恶烷。通过4- exo trig氨基甲酰基自由基环化反应-二硫代氨基甲酸酯基团转移反应制得的熔融和螺环β-内酰胺可在不断裂的四元环断裂的情况下被还原。二乙基四乙酰基-D-吡喃葡萄糖基二硫代氨基甲酸酯取决于反应条件和还原剂的选择,在有或没有酰氧基迁移的情况下选择性地还原Aβ。对于涉及亲核基团中间体的系统,可以观察到从D 3 PO 2 -Et 3 N引入氘,但对于通过酰氧基在葡萄糖衍生物上迁移获得的亲电子基团,则观察不到这种情况。