Recyclable chiral dinuclear copper(II) complexes catalyzed asymmetric Friedel–Crafts alkylation of 1-naphthol using N-tosyl aldimine

• Synthesis of chiral Schiff base ligands using different linkers
• First asymmetric F–C reaction of 1-naphthol with tosyl imine using copper catalyst
• Good catalytic activity in terms of product yields and enantioselectivity
• High degree of recyclability and easy separation of products
• Proposed catalytic mechanism based of UV–Visible spectra and kinetics studies

A highly efficient dinuclear copper complex catalyzed Friedel–Crafts reaction has been demonstrated for the alkylation of 1-naphthol using N-tosyl aldimine. In this context, various chiral amino alcohol derived Schiff base ligands with different achiral and chiral linkers were synthesized and their copper (II) complexes were generated in situ. One of the dinuclear copper complexes with chiral linker has emerged as an efficient catalyst and affords the desired arene products in excellent enantioselectivities (ee up to 99%) with very good yields (up to 98%). The dinuclear catalyst used in this study was recoverable and recyclable with retention of its catalytic activity.