▎ 摘　　要

NOVELTY - Preparing graphene oxide/chitosan/polyvinyl alcohol composite microsphere immobilized copper catalyst comprises (i) preparing graphene oxide, adding graphene oxide into chitosan solution, and ultra-sonicating at room temperature for 15-60 minutes, then adding polyvinyl alcohol and glutaraldehyde, and then sonicating at room temperature for 30-60 minutes to obtain first system, adding absolute ethanol into saturated aqueous sodium hydroxide solution and mixing evenly, and cooling to room temperature to obtain second system, (ii) dropping the first system prepared in step (i) into the second system to form microspheres, filtering, washing, and drying at room temperature, and (iii) soaking the product prepared in step (ii) in water at 40-80 ℃ for 1-2 hours, then adding excess copper(II) sulfate aqueous solution to stir the reaction, filtering to take the filter residue, drying at 40-60 ℃ for 12-24 hours, and grinding. USE - The graphene oxide/chitosan/polyvinyl alcohol composite microspheres immobilized copper catalyst is useful for preparing chiral organic boridies. ADVANTAGE - The prepared chiral organoboride: has high product yield, high enantioselectivity, less catalyst consumption, mild reaction conditions and other advantages; can carrying out at room temperature, easy to operate, cost-saving, and environmentally friendly; and can reuse catalytic material. DETAILED DESCRIPTION - Preparing graphene oxide/chitosan/polyvinyl alcohol composite microsphere immobilized copper catalyst comprises (i) preparing graphene oxide, adding graphene oxide into chitosan solution, and ultra-sonicating at room temperature for 15-60 minutes, then adding polyvinyl alcohol and glutaraldehyde, and then sonicating at room temperature for 30-60 minutes to obtain first system with a mass fraction of graphene oxide of 1-5%, adding absolute ethanol into saturated aqueous sodium hydroxide solution and mixing evenly, and cooling to room temperature to obtain second system, where the volume ratio between saturated aqueous sodium hydroxide solution and absolute ethanol is 4:(3-8), (ii) dropping the first system prepared in step (i) into the second system to form microspheres, filtering, washing, and drying at room temperature, and (iii) soaking the product prepared in step (ii) in water at 40-80 ℃ for 1-2 hours, then adding excess copper(II) sulfate aqueous solution to stir the reaction, filtering to take the filter residue, drying at 40-60 ℃ for 12-24 hours, and grinding to obtain graphene oxide/chitosan/polyvinyl alcohol composite microsphere-immobilized copper catalyst. An INDEPENDENT CLAIM is included for use of graphene oxide/chitosan/polyvinyl alcohol composite microspheres immobilized copper catalyst for preparing chiral organic boridies of formula (I), comprising (P1) taking α,β-unsaturated ester, bis(pinacolato)diboron, graphene oxide/chitosan/polyvinyl alcohol composite microspheres immobilized copper catalyst and ligand (R)-(S)-josiphos according to the ratio of the amount of substance 1: (1.2-2): (0.01-0.02): (0.01-0.03), adding additive to pre-dissolve, adding water, mixing and stirring at room temperature for 2.5-6 hours, filtering, and using the filtrate and filter residue;, where the additive is methanol, ether and/or toluene, and (P2) taking the filtrate obtained in step (P1), purifying and drying to obtain pure chiral organoboridy, washing the filter residue obtained in step (P1) and drying, and recovering the graphene oxide/chitosan/polyvinyl alcohol composite microsphere-immobilized copper catalyst for recycling. R = phenyl, p-chlorophenyl, 2-phenylethyl, o-methylphenyl or thienyl.