ChemInform Abstract: Enantioselective Oxidative Coupling of 2‐Naphthol Derivatives by Copper‐(R)‐1,1′‐binaphthyl‐2,2′‐diamine‐TEMPO Catalyst.

Abstract

Enantioselective Oxidative Coupling of 2-Naphthol Derivatives by Copper--(R)-1,1'-binaphthyl-2,2'-diamine-TEMPO Catalyst. -Addition of TEMPO to the (R)-BINAM-CuCl complex is crucial as it increases dramatically the reaction rate and selectivity of the reaction at room temperature. -(ALAMSETTI, S. K.; POONGUZHALI, E.; GANAPATHY, D.; SEKAR*, G.; Adv. Synth. Catal. 355 (2013) 14-15, 2803-2808, http://dx.doi.org/10.1002/adsc.201300513 ; Dep. Chem., Indian Inst. Technol., Chennai 600 036, India; Eng.) -Y. Steudel 13-102

Oxidative Coupling between Two Hydrocarbons: An Update of Recent C–H Functionalizations

“…192 Recently, Sekar and co-workers reported an efficient chiral copper catalytic system for the asymmetric oxidative homocoupling of 2-naphthol derivatives 227 to synthesize enantiomerically enriched BINOL derivatives (Scheme 127). 193 Addition of a catalytic amount of TEMPO (2,2,6,6tetramethylpiperidin-1-yl oxyl) combined with copper-(R)-BINAM complex greatly enhanced the reactivity and enantioselectivity of this oxidative coupling and also lowered the reaction temperature to room temperature in CH 2 Cl 2 solvent. A similar work was later reported by Breuning's group.…”

TEMPO in Chemical Transformations: From Homogeneous to Heterogeneous

“…291 Sekar et al developed an efficient chiral copper catalyzed system [(R)-BINAM-CuCl-TEMPO] for an asymmetric oxidative coupling of 2-naphthol derivatives to synthesize enantiomerically pure BINOL derivatives. 292 Surprisingly, the rate of the reaction was drastically increased by adding TEMPO to the (R)-BINAM-CuCl complex and enantiomeric excess (ee) was maintained up to 97% at room temperature. ditions.…”