A Passerini three component condensation between a carboxylic acid, an aldehyde, and an isocyanide at high temperature under solvent-free conditions was developed. This methodology allows the formation of a broad range of alpha-acyloxyamides in excellent yields in short reaction times. (C) 2011 Elsevier Ltd. All rights reserved.
Supported <i>p</i>-Toluenesulfonic Acid as a Highly Robust and Eco-Friendly Isocyanide Scavenger
作者:Jhonny Azuaje、Alberto Coelho、Abdelaziz El Maatougui、José Manuel Blanco、Eddy Sotelo
DOI:10.1021/co100035z
日期:2011.1.10
We document here the use of polymer-supported p-toluenesulfonic acid as a highly effective, robust, economical and eco-friendly isocyanide scavenger. The herein described strategy; circumvent the intense and repulsive odor of volatile isocyanides, enabling simplified and odorless workup and purifications. The usefulness of the new scavengers has been validated in a set of diverse isocyanide-based organic transformations and this approach is also amenable to parallel synthesis techniques.
A Mild Method for the Efficient [3,3]-Sigmatropic Rearrangement of <i>N,O</i>-Diacylhydroxylamines
A mild, general method for the [3,3]-sigmatropic rearrangement of N,O-diacylhydroxylamines, employing a combination of mild base and Lewis acid, is described. Employing stoichiometric amounts of reagents with respect to substrate provides alpha-acyloxyamides, whereas an excess of reagents favors formation of cyclic orthoamides.