A chiral bisphosphine ligand and an iridium complex catalyst, and a method for preparing the asymmetric hydrogenation synthesis of (s) - Application of metolachlor

The present invention relates to a class of chiral bisphosphine ligand and an iridium complex catalyst, method of preparation and use thereof. The chiral diphosphine ligand is of the (R) - (S) -1- dimethylaminoethyl ferrocene as the starting material, by reaction with diphenylphosphine chloride in the action of butyllithium, and then alkyl diaryl phosphine obtained by a substitution reaction. These chiral bisphosphine ligand of iridium trichloride respectively biscyclooctadiene complex and tetrabutylammonium iodide, acetic acid effect is obtained imine hydrogenation catalyst is asymmetric. With this iridium - bisphosphonic Catalysts -N- methyl-6-ethyl-ethylene-methylaniline (EMA-imine) hydrogenation reaction to obtain (S) -N- (1- methoxy-2-propyl yl) -2-methyl-6-ethylaniline ((S) -NAA), of the enantiomeric excess (ee) up to 86.5%; and (S) -NAA acylation with chloroacetyl chloride to obtain ee value of 86% (S) - metolachlor. Thus, the bisphosphine ligand of the present invention can be used to provide a herbicide synthesis of chiral (S) - metolachlor.