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
N-arylation-carbo-amination-C-arylation of O-homoallylhydroxylamines with two different aryl bromides provides rapid entry to differentially arylated N-aryl-3-arylmethylisoxazolidines in good yields with excellent diastereoselectivity. The obtained isoxazolidines can be reductively cleaved to cis-N-aryl-beta-amino alcohols in short times and in high yields at room temperature.