Enantioselective Oxidative Coupling of 2-Naphthol Derivatives by Copper-(<i>R</i>)-1,1′-Binaphthyl-2,2′-diamine-TEMPO Catalyst
作者:Santosh Kumar Alamsetti、Elamvazhuthi Poonguzhali、Dhandapani Ganapathy、Govindasamy Sekar
DOI:10.1002/adsc.201300513
日期:2013.10.11
AbstractAn efficient chiral copper catalytic system [(R)‐(+)‐1,1′‐binaphthyl‐2,2′‐diamine‐copper(I) chloride‐TEMPO] for the asymmetric oxidative coupling of 2‐naphthol derivatives to synthesize enantiomerically enriched BINOL derivatives has been developed with good to excellent enantiomeric excess (up to 97% ee). The addition of a catalytic quantity of 2,2,6,6‐tetramethylpiperidin‐1‐yl oxyl (TEMPO) to the copper‐(R)‐(+)‐1,1′‐binaphthyl‐2,2′‐diamine complex greatly enhanced the reactivity and enantioselectivity of the enantioselective oxidative coupling of 2‐naphthol derivatives and also reduced the reaction temperature from 90 °C to room temperature in dichloromethane solvent.magnified image