A New Synthesis of Imidazolidin-2-ones via Pd-Catalyzed Carboamination of N-Allylureas
摘要:
A new strategy for the preparation of substituted imidazolidin-2-ones in two steps from readily available N-allylamines is described. Addition of the amine starting materials to isocyanates affords N-allylureas, which are converted to imidazolidin-2-one products with generation of two bonds and up to two stereocenters when treated with aryl bromides and catalytic amounts of Pd-2(dba)(3)/Xantphos in the presence of (NaOBu)-Bu-t.
Use of Aryl Chlorides as Electrophiles in Pd-Catalyzed Alkene Difunctionalization Reactions
作者:Brandon R. Rosen、Joshua E. Ney、John P. Wolfe
DOI:10.1021/jo100344k
日期:2010.4.16
The development of conditions that allow use of inexpensive aryl chlorides as electrophiles in Pd-catalyzedalkenecarboamination and carboetherification reactions is described. A catalyst composed of Pd(OAc)2 and S-Phos minimizes N-arylation of the substrate and prevents formation of mixtures of regioisomeric products. A number of heterocycles, including pyrrolidines, isoxazolidines, tetrahydrofurans