Synthesis of N,O-acetals by net amide C N bond insertion of aldehydes into N-acyl phthalimides and N-acyl azoles
作者:Robert N. Enright、Jeffrey L. Grinde、Lincoln I. Wurtz、Matthew S. Paeth、Tekoa R. Wittman、Emily R. Cliff、Yessra T. Sankari、Lucas T. Henningsen、Chuchen Tan、Joseph D. Scanlon、Patrick H. Willoughby
DOI:10.1016/j.tet.2016.08.041
日期:2016.10
We found that N-acyl phthalimides and several N-acylated azoles are capable of reacting with aldehydes to form O-acyl-N,O-acetals in an apparent amide CN bond insertion. In the context of N-acyl phthalimides, the reaction is mediated by substoichiometric amounts of sodium iodide and potassium phthalimide. DFT computations supported a proposed mechanism and provided insights into the effect of the alkali
我们发现N-酰基邻苯二甲酰亚胺和几种N-酰化的唑能够与醛反应形成明显的酰胺C N键插入的O-酰基-N,O-缩醛。在N-酰基邻苯二甲酰亚胺的情况下,该反应由亚化学计量的碘化钠和邻苯二甲酰亚胺钾介导。DFT计算支持提出的机制,并提供了对碱金属添加剂效果的见解。该策略可用于从一系列醛中制备无数的N,O-缩醛。还开发了一种一锅法,其中N-酰基邻苯二甲酰亚胺在形成N,O-缩醛产物之前原位生成。一锅法用于证明衍生自咪唑,吡唑,(苯并)三唑和四唑的活化酰胺也是合适的底物。总而言之,这些研究提供了一种在温和条件下由廉价的起始原料合成各种N,O-缩醛的方法。