Highly Effective and Diastereoselective Synthesis of Axially Chiral Bis-sulfoxide Ligands via Oxidative Aryl Coupling
摘要:
A series of axially chiral bis-sulfoxide ligands have been efficiently synthesized via oxidative coupling with high diastereoselectivities. The axial chirality is well controlled by the tert-butylsulfinyl or the p-tolylsulfinyl group. These axially chiral bis-sulfoxides proved to be remarkably efficient ligands for the rhodium-catalyzed asymmetric 1,4-addition of arylboronic acids to 2-cyclohexenone with 99% ee.
Atropo-diastereoselective coupling of aryllithiums and arynes — variations around the chiral auxiliary
作者:David Augros、Boubacar Yalcouye、Anaïs Berthelot-Bréhier、Matthieu Chessé、Sabine Choppin、Armen Panossian、Frédéric R. Leroux
DOI:10.1016/j.tet.2016.01.047
日期:2016.8
The atropo-selective coupling of in situ generated arynes and aryllithiums bearing various chiralauxiliaries ortho to lithium (tert-butylsulfoxide, para-tolylsulfoxide, tartrate-derived chiral diethers and oxazolines) is described. Chiral oxazolines showed the best results in terms of yields of coupling products. Different reaction parameters like the nature of the aryne precursor, the oxazoline,
A class of novel chiral tert-butanesulfinylphosphine ligands were designed and synthesized by a concise two-step route with high yields. High activities and enantioselectivities (up to 94% ee) were achieved when using them in catalytic asymmetric diethylzinc addition to diphenylphosphionyl imines.