O-Alkenyl Hydroxylamines: A New Concept for Cyclofunctionalization
摘要:
Treatment of O-homoallylhydroxylamines with palladium(II) and copper(II) in the presence of a base, methanol, and carbon monoxide results in the formation of isooxazolidines. An electron-withdrawing group on the hydroxylamine nitrogen is essential. When carbamate groups are used the products are formed exclusively as their cis isomers.
Palladium-Catalyzed Highly Stereoselective Synthesis of <i>N</i>-Aryl-3-arylmethylisoxazolidines via Tandem Arylation of <i>O</i>-Homoallylhydroxylamines
The palladium-catalyzed tandem arylation of O-homoallylhydroxylamines with 2 equiv of aryl bromides was examined. With Pd2(dba)3 (1 mol %) as the catalyst, Xantphos (2 mol %) as the ligand, and NaOt-Bu as the base, the reactions of O-homoallylhydroxylamines with aryl bromides via sequential N-arylation/cyclization/C-arylation in toluene afforded the corresponding N-aryl-3-arylmethylisoxazolidines in