Switchable Synthesis of 4,5-Functionalized 1,2,3-Thiadiazoles and 1,2,3-Triazoles from 2-Cyanothioacetamides under Diazo Group Transfer Conditions
作者:Valeriy O. Filimonov、Lidia N. Dianova、Kristina A. Galata、Tetyana V. Beryozkina、Mikhail S. Novikov、Vera S. Berseneva、Oleg S. Eltsov、Albert T. Lebedev、Pavel A. Slepukhin、Vasiliy A. Bakulev
DOI:10.1021/acs.joc.6b02736
日期:2017.4.21
3-thiadiazoles and 1,2,3-triazoles from 2-cyanothioacetamides and sulfonyl azides is described. Under diazo transfer conditions in the presence of a base in an aprotic solvent 2-cyanothioacetamides operating as C–C–S building blocks produce 5-amino-4-cyano-1,2,3-thiadiazoles exclusively. The use of alkoxide/alcohol system completely switches the reaction course due to the change of one of the reaction centers
描述了由2-氰基硫代乙酰胺和磺酰基叠氮化物高产率地进行溶剂基控制的,无过渡金属的4,5-官能化的1,2,3-噻二唑和1,2,3-三唑的合成。在重氮转移条件下,在非质子传递溶剂中存在碱的情况下,用作C–C–S结构单元的2-氰基硫代乙酰胺仅产生5-氨基-4-氰基-1,2,3-噻二唑。由于2-氰基硫代乙酰胺(CC-N结构单元)中一个反应中心的变化,使用醇盐/醇系统可以完全改变反应过程,从而形成5-磺酰胺基1,2,3。 -三唑-4-碳硫代酰胺钠盐为唯一产品。后者是5-氨基-1,2,3-噻二唑-4-羧酰亚胺的良好前体,其在天然质子介质中或在酸性条件下发生于康福斯类型的重排。