Dibenzophosphole oxides were obtained from secondary hydrophosphine oxides with a biphenyl group by dehydrogenation via phosphine–hydrogen and carbon–hydrogen bond cleavage in the presence of a catalytic amount of palladium(II) acetate, Pd(OAc)2. By using this reaction, a ladder-type dibenzophosphole oxide could also be synthesized by double intramolecular dehydrogenative cyclization.
Secondary phosphineoxides were synthesized using a two-step procedure: a basic hydrolysis of oxazaphospholidine SP-2 to form the secondary phosphinate RP-4, followed by the stereoselective nucleophilic attack of organometallic reagents to obtain the expected enantioenriched secondary phosphineoxides.
次级膦氧化物的合成过程分两步进行:将氧杂氮磷吡啶S P -2进行碱性水解以形成次级次膦酸酯R P -4,然后对有机金属试剂进行立体选择性亲核攻击,从而获得预期的对映体富集的次级膦氧化物。
Stereoselective Addition of Grignard Reagents to New P-Chirogenic N-Phosphinoylbenzaldimines: Effect of the Phosphorus Substituents on the Stereoselectivity
give both diastereoisomers in high yields and with promising diastereomeric ratios. Then N-[(tert-butyl)(phenyl)phosphinoyl]benzaldimine, which displayed the best results, was subjected to the 1,2-addition of various Grignardreagents to evaluate the best chiral induction due to the stereogenic phosphorus atom. The corresponding adducts were obtained in excellent yields and with moderate to excellent diastereoisomeric
A new protocol for the dearylation of arylphosphine oxides was developed using sodium hydride (NaH) in the presence of lithium iodide (LiI). The transient sodium phosphinite could be functionalized with a range of electrophiles in a one-pot fashion.
Asymmetric synthesis of chiral P-stereogenic triaryl phosphine oxides via Pd-catalyzed kinetic arylation of diaryl phosphine oxides
作者:Yong Zhang、Huan He、Qiuyan Wang、Qian Cai
DOI:10.1016/j.tetlet.2016.10.048
日期:2016.11
Enantioselective C–Pcross-coupling of diarylphosphine oxides with ortho-substituted aryl iodides has been achieved via kinetic resolution strategy, affording chiral triarylphosphine oxides in high yields and with moderate to high enantioselectivity.