Harnessing the Lewis Acidity of HFIP through its Cooperation with a Calcium(II) Salt: Application to the Aza-Piancatelli Reaction
作者:David Lebœuf、Lucile Marin、Bastien Michelet、Alejandro Perez-Luna、Régis Guillot、Emmanuelle Schulz、Vincent Gandon
DOI:10.1002/chem.201603592
日期:2016.11.2
A method to extend the scope of the aza‐Piancatelli reaction between 2‐furylcarbinols and anilines is depicted. We found that 1,1,1,3,3,3‐hexafluoro‐2‐propanol (HFIP) is the solvent of choice for this transformation, as it outcompetes the usual solvents in terms of rate and yield. Side reactions and other issues raised by the title reaction are prevented, thereby providing an avenue to complex molecules
描述了一种扩展2-呋喃基甲醇和苯胺之间的氮杂-Piancatelli反应范围的方法。我们发现1,1,1,1,3,3,3-六氟-2-丙醇(HFIP)是此转化的首选溶剂,因为它在速率和收率方面都优于常规溶剂。防止了副反应和标题反应引起的其他问题,从而为以前无法接近的复杂分子提供了途径。进行了路易斯酸度研究和计算,以揭示HFIP的作用。根据这些结果,我们建议HFIP实际上起路易斯酸的作用,并且与钙(II)盐结合使用时,可以增强其酸度。