Palladium-Catalyzed Enantioselective Intramolecular Heck Carbonylation Reactions: Asymmetric Synthesis of 2-Oxindole Ynones and Carboxylic Acids.

Abstract

Herein, we report a Pd-catalyzed enantioselective domino Heck carbonylation reaction of o-iodoacrylanilides with terminal alkynes and water as the nucleophiles, affording a diversity of β-carbonylated 2-oxindole derivatives bearing a 3,3-disubstituted all-carbon quaternary stereocenter, in high yields (55-99 %) with good to excellent enantioselectivities (up to 99 % ee). The synthetic utilities of the protocol were demonstrated in the gram-scale synthesis of 2-oxindole-derived ynone 3 ea and carboxylic acid 4 a, as well as the facile synthesis of chiral 2-oxindoles with a pyrazole or isoxazole moiety.