肟的无气味硫缩醛/酮化反应

探讨了以无气味且稳定的α-羰基二硫缩烯酮(1)作为代硫醇试剂的肟(2)的硫缩醛/酮化反应. 在乙酰氯-乙醇(体积分数95%)或4-十二烷基苯磺酸(DBSA)-水体系中及回流条件下, 化合物1与肟2能有效地进行硫缩醛/酮化反应. 反应过程中未闻到硫醇的恶臭气味.

Odorless and Efficient Thioacetalization Reaction of Oximes

Thioacetals are important compounds because they can be considered as both useful protecting groups of carbonyl compounds in the synthesis of multi-functional complex molecules and acyl carbanion equi-valents in C—C bond forming reactions.Since many reactions have been developed to prepare oximes from non carbonyl compounds,to lead to a novel and efficient method for thioacetal preparation,transthioacetalization of oximes has received more and more attention.Unfortunately,the transformation usually suffers from the use of harmful,odorous thiols which can lead to serious safety and environment problems.From the green chemistry point of view,an efficient and odorless transthioacetalization of oximes involving an environment friendly reagent is of great importance and necessity.In this work,using odorless and stable α-oxo ketene dithioacetals 1 as thiol equivalents,the thioacetalization reaction of oximes 2 were studied.In the reaction system of MeCOCl-EtOH(95%) or 4-dodecylbenzenesulfonic acid(DBSA)-H2O,the thioacetalization reaction were carried out in reflux temperature.It is noteworthy that the odor of thiols can not be perceived during either the reaction or workup.