Organocatalytic asymmetric cyanation of isatin derived N-Boc ketoimines
作者:Yun-Lin Liu、Jian Zhou
DOI:10.1039/c2cc36665g
日期:——
We report the first catalytic asymmetric cyanation of N-Boc ketoimines, which enables highly enantioselective synthesis of oxindole based α-amino nitriles. An unprecedented tandem aza-Wittig/Strecker reaction is also developed, emerging as a promising strategy for the catalytic asymmetric cyanation of ketoimines formed in situ from achiral ketones.
The Quinine Thiourea-Catalyzed Asymmetric Strecker Reaction: An Approach for the Synthesis of 3-Aminooxindoles
作者:Dong Wang、Jinyan Liang、Jingchao Feng、Kairong Wang、Quantao Sun、Long Zhao、Dan Li、Wenjin Yan、Rui Wang
DOI:10.1002/adsc.201200630
日期:2013.1.9
An organocatalytic enantioselective Streckerreaction for the synthesis of 3-amino-3-cyanooxindoles has been developed. Employing a quinine-derived thiourea catalyst, the nucleophilic addition of trimethylsilyl cyanide to N-Boc-ketimines affords 3-amino-3-canooxindoles in good to excellent yields (78–98%) and very good enantioselectivities (up to 94%). Furthermore, to the best of our knowledge, this
combined systems of amino acid/BINAP derivative/Ru(II) complexes and lithium compounds was examined. The use of an appropriate combination of amino acid and BINAP ligands achieved high enantioselectivity for a variety of α-alkynyl (Val/XylBINAP/Ru), α-alkenyl (Val/TolBINAP/Ru), and α-aryl imino esters (Val/XylBINAP/Ru) as well as an isatin-derived cyclic imino amide (t-Leu/BINAP/Ru) to afford the α-cyano-α-amino