Phosphoramidite Ligands Based on Simple 1,2‐Diols: Synthesis, Use in Copper‐Catalyzed Asymmetric Additions, and Achirotopic Stereogenic Phosphorus Centres

Abstract

Phosphoramidite ligands are widely used in catalysisa nd normally constructed from large C 2symmetrical diols such as BINOL or TADDOL.W e report here on new ligands based on as et of simple diols that had been previously overlooked. Ligands based on (S,S)-trans-cyclohexanediol and( R,R)-(+ +)-1,2-diphenyl-1,2-ethanediol, in combination with both chiral anda chiral amines,w ere tested in 3d ifferent copper-catalyzed asymmetric reactions and up to 89% ee was observed. Ad ifferent ligandg avet he best results in each reactione xamined.U sing mesocis-cyclohexanediol and meso-cis-diphenyl-1,2-ethanediol with ac hiral non-racemic amine gave diastereomeric ligands bearing achirotopics tereogenic phosphorus atoms which were characterized with the assistance of X-ray crystallography and variablet emperature NMRs tudies.T his workp rovides an ew set of ligands that may be useful in some asymmetric reactions when phosphoramidites based on BINOL and TADDOL are ineffective. We also identify an ovels tereochemical feature of phosphoramidites that may be useful in asymmetric catalysis and ligand design.

A Chiral Triazole Ligand for Enantiodivergent Catalysis in Asymmetric 1,4‐Addition of Arylboronic Acid

“…The authors have cited additional references within the Supporting Information. [13,22,[24][25][26][27][28]…”