enantioselective Pd(II)-catalyzed intramolecularoxidative amination reaction was developed utilizing the commercially available chiral X-type ligand (1S)-(+)-camphorsulfonic acid. The Wacker-type cyclization produced chiral indoline products with enantioselectivies up to 45% ee. Electronic structure calculations employing density functional theory support a trans-aminopalladation mechanism.
Synthesis of nitrogen heterocycles via Pd-catalyzed cross-coupling of o-alkenyl anilides with vinylic halides and triflates
作者:Richard C. Larock、Paola Pace、Hoseok Yang、Charles E. Russell、Sandro Cacchi、Giancarlo Fabrizi
DOI:10.1016/s0040-4020(98)00589-4
日期:1998.8
The palladium-catalyzed cross-coupling of o-allylic and o-vinylic anilides with vinylic halides and triflates produces substituted nitrogen heterocycles in good to high yields by a process involving vinylpalladium addition to the olefin, rearrangement to a π-allylpalladium intermediate and subsequent intramolecular nucleophilic displacement of palladium. Different reactivity and regioselectivity in the
A method for the preparation of indolines via palladium-catalyzed aerobic intramolecular allylic CH activation was developed. Oxygen was successfully used as oxidant with catalytic amount of 1,4-benzoquinone. 16 examples were reported, the majority of substrates gave moderate to good yields.