CHIRAL QUATERNARY BENZOPHENONE HYDRAZONIUM SALT DERIVATIVES - EFFICIENT CHIRAL CATALYSTS FOR THE ENANTIOSELECTIVE PHASE-TRANSFER ALKYLATION OF IMINES - APPLICATION TO SYNTHESIS OF CHIRAL PRIMARY AMINES

(2S)-1-Methyl-1-[N-(diphenylmethylene)]-2-hydroxymethylpyrrolidine hydrazonium iodide I-a has been designed to catalyse the enantioselective phase-transfer alkylation of N-(diphenylmethylene) benzenemethanamine II. Although the weak acidic character of the latter, alkylations have been performed within reasonable reaction times. Optically active Primary amines III a-e have been prepared in good chemical yields and up to 94% e.e. using 2-5 mol-% of the chiral catalyst only.