Process for synthesizing highly optically active 1,3-disubstituted allenes

A process for synthesizing optically active 1,3-disubstituted allenes, in a heated reaction comprising a functionalized terminal alkyne, an aldehyde and a chiral secondary amine as reactants, a divalent copper salt as a catalyst and an organic solvent, thereby producing a variety of functionalized axially chiral 1,3-disubstituted allenes;

• wherein the process consists of:
• adding in sequence to a reaction under nitrogen atmosphere:
• a divalent copper salt, a chiral secondary amine, a terminal alkyne, an aldehyde and an organic solvent;
• subjecting the reaction to anhydrous and anaerobic treatment by heating for 12-24 h in an oil bath;
• returning the reaction to room temperature,
• diluting the reaction with the organic solvent,
• washing the reaction with dilute hydrochloric acid,
• separating the organic phase,
• extracting the aqueous phase with the organic solvent,
• washing with saturated brine,
• drying with anhydrous sodium sulfate, filtering, concentrating and subjecting reaction products to column chromatography, so as to obtain the axially chiral allene;
• wherein the reaction has a following reaction equation:
• wherein R1 comprises functional groups selected from glycosidic units, primary alcohols, secondary alcohols, tertiary alcohols, amides, malonates, alkyl group or aryl group, and R2 is an alkyl group or an aryl group.