The Stereoselective Construction Of Asymmetric Carbon-phos-phine Bonds And The Synthesis Of Chiral Phosphine Ligands

Organic phosphorus chemistry is closely related to human life and has important applications in medicine,agriculture,biological engineering and other aspects.The paper focuses on four parts: The synthesis of chiral hydrocarbyl menthyl phosphine oxide compounds;The stereoselectivity addition of P?Stereogenic Secondary Phosphine Oxide to Activated Alkenes;The synthesis and raccemic transformation of?S_P?-menthyl phenylphosphonic borane complex;The alkylation of?S_P?-menthyl phenylphosphonic borane complex alkylation.At fiirst,we have tried to synthesize chiral hydrocarbyl menthyl phosphine oxides in three ways.Method 1,Phosphorus trichloride 1 was reacted with alcohol 2 to produce alkoxy phosphorus dichloride 3,reacted with menthyl Grignard reagent 4,hydrolyzed to give 5,then reacted with the other Grignard reagent 6 to obtain the chiral hydrocarbyl menthyl phosphine oxide 7.Method 2,4 reaction with 1 get menthyl phosphorus dichloride 8,then reacted with 2 and hydrolysis of 5.Method 3,4 and trimethyl phosphite 10 reacted and hydrolyzed to give 5.In terms of the operational process,the reaction effect and the degree of post-processing,we selected method 1 for the synthesis of chiral hydrocarbyl menthyl phosphine oxide the best way.Secondly,functionalized P,C-stereogenic tertiary phosphine oxides were prepared by the addition of?R_P?-menthyl phenylphosphine oxide 12 to activated olefins 13,in high drP and dr C,and were isolated in excellent yields.The reaction was readily catalyzed by Ca?OH?₂ or occurred with gentle heating.A wide range of substrates,including vinyl ketones,esters,nitriles,and nitro alkenes,can be used in the reaction.Based on our previous research,?S_P?-menthyl phenylphosphine borane complex 18b was synthesized from the new synthesis method.We used phenylphosphorus dichloride 17b coordinated with borane,and then reduced to obtain 18b/18b',and finally purified to obtain 18b.In order to obtain?R_P?-menthyl phenylphosphine borane complex 18b',we studied the 18b by racemization.Finally,18b reacted with different substituted halides by phase transfer to completed alkylation in a yield greater than 99% and synthesized a series of tri-substituted phosphine borane compounds.