Study On Asymmetric Carbonyl Synthesis Of Chiral Aryl Propionate

Chirality is closely related to the phenomena of life,asymmetric catalytic synthesis by chiral catalysts is the most effective method to obtain chiral compounds.In this paper,the process of asymmetric carbonylation reactions(asymmetric carboxylation,asymmetric hydroesterification and asymmetric hydroformylation)were optimized and the optimum reaction conditions of the three kinds of chiral carbonylation reactions were obtained;we first applied the rhodium-phosphine chiral ionic liquid catalyst to catalyze the asymmetric hydroformylation reaction of arylene olefins to achieve the recycling of precious metals.The optimum conditions for the asymmetric carboxylation of 1-phenylethanol determined by research were as follows: the main catalyst PdCl2;the cocatalyst CuCl2;the chiral ligand BNPPA [(S)-(+)-1,1’-Binaphthyl-2,2’-diyl hydrogenphosphate];the solvent toluene;the reaction temperature 100 ?C;the CO pressure 5 MPa;the reaction time 22 h;the dosage of main catalyst Pd/S(molar ratio,S is substrate)=0.07;the dosage of chiral ligand P/Pd=3;the dosage of cocatalyst Cu/Pd=6.Under this reaction process conditions,the conversion rate of 1-phenylethanol was 94%;the yield of 2-phenylpropionic acid was 84%;the ratio of isomer/normal was 95/5;the e.e.value was 18%.The optimum conditions for the asymmetric esterification of styrene determined by experiment were as follows: the main catalyst PdCl2;the cocatalyst CuCl2;the chiral ligand BNPPA[(S)-(+)-1,1’-Binaphthyl-2,2’-diyl hydrogenphosphate];the solvent toluene;the reaction temperature 80 ?C;the CO pressure 4 MPa;the reaction time 14 h;the dosage of the main catalyst Pd/S=0.05;the dosage of chiral ligand P/Pd=3;the dosage of cocatalyst Cu/Pd=6.Under this reaction process conditions,the conversion rate of styrene was 93%;the yield of 2-phenylpropionic acid methyl ester was 82%;the ratio of isomerism/normal was 94/6;the e.e.value was 43%.The optimum conditions for the asymmetric hydroformylation of styrene determined by experiment were as follows: the catalyst Rh(acac)(CO)2;the chiral ligand(R,R)-Ph-BPE[(-)-1,2-dou-ble((2R,5R)-2,5-diphenylphosphine)ethane];the solvent toluene;the reaction temperature 60 ?C;the syngas(CO/H2=1)pressure 2 MPa;the reaction time 4 h;the dosage of catalyst Rh/S=1/2000;the dosage of chiral ligand P/Rh=4.Under this reaction process conditions,the conversion rate of styrene was 100%;the yield of 2-phenyl-propionaldehyde was 96%;the ratio of isomer/normal was 98/2;the e.e.value was 67%.In this study,functionalized ionic liquids [Bmim][Rhx(CO)y] were formed by imidazolium salt ion liquid [Bmim]Cl with carbonyl rhodium salt K[Rhx(CO)y].The rhodium-phosphine chiral ionic liquid catalyst was synthesized in situ by functionalized ionic liquid [Bmim][Rhx(CO)y] with a chiral ligand(R,R)-Ph-BPE in the process of asymmetric hydroformylation of styrene,and the optimum conditions for asymmetric hydroformylation of styrene were determined.Under this reaction process conditions: the solvent toluene;the reaction temperature 80 ?C;the syngas(CO/H2=1)2 MPa;the reaction time 4 h;the dosage of functionalized ionic liquid [Bmim][Rhx(CO)y] 0.6 g,the dosage of chiral ligand(R,R)-Ph-BPE 19 mg(0.0384mmol)and the dosage of hydroquinone 5 mg when the amount of substrate was 9.6 mmol,the conversion rate of styrene was 82%,the yield of 2-phenyl-propionaldehyde was 60%,the e.e.value was 10%.