Oxygen-Substituted Isocyanates: Blocked (Masked) Isocyanates Enable Controlled Reactivity
作者:Ryan A. Ivanovich、Dilan E. Polat、André M. Beauchemin
DOI:10.1002/adsc.201701046
日期:2017.12.19
Oxygen‐substituted isocyanates (O‐isocyanates) are rare isocyanates with a reported propensity to trimerize, a side‐reaction that severely limited their use in synthesis. Herein, the development of blocked (masked) O‐isocyanate precursors that form this reactive intermediate in situ provide controlled reactivity, allowing the first examples of cascade reactions involving O‐isocyanates. Complex hydroxylamine‐derived
氧取代的异氰酸酯(O-异氰酸酯)是稀有的异氰酸酯,据报道具有三聚作用的倾向,这种副反应严重限制了它们在合成中的使用。这里,原位形成该反应性中间体的嵌段(掩蔽的)O-异氰酸酯前体的开发提供了可控的反应性,这是涉及O-异氰酸酯的级联反应的第一个例子。复杂的羟胺衍生的乙内酰脲和二氢尿嘧啶化合物可以从α-和β-氨基酯快速组装,这说明了被掩盖的O-异氰酸酯作为羟胺衍生的结构单元的便利性。提供了O-异氰酸酯中间体的中间证据。