Palladium catalyzed cascade umpolung allylation/acetalation for the construction of quaternary 3-amino oxindoles
作者:Xi-Shang Sun、Xin Chang、Li-Min Shi、Zuo-Fei Wang、Liang Wei、Chun-Jiang Wang
DOI:10.1039/d1cc03075b
日期:——
Herein we reported a highly diastereoselective synthesis of quaternary 3-amino oxindoles bearing an acetal unit via a palladiumcatalyzed three-component cascade umpolung allylation/acetalation process. An array of 3-amino 3-allyl oxindoles incorporating diversified functional groups were prepared in good yields with exclusive diastereoselectivities. Further investigation demonstrated that the current
The Pd-catalyzed cross-coupling of allylic carbonates and allyIB(pin) is described. The regioselectivity of this reaction is sensitive to the bite angle of the ligand, with small-bite-angle ligands favoring the branched substitution product. This mode of regioselection is consistent with a reaction that operates by a 3,3' reductive elimination reaction. In the presence of appropriate chiral ligands, this reaction is rendered enantioselective and applies to both aromatic and aliphatic allylic carbonates.