摘要
以轴手性的1,1’-联-2-萘酚(BINOL)和1,1’-螺二氢茚-7,7’-二酚(SPINOL)为骨架的手性磷酸已经被广泛应用于不对称催化领域,在数以百计的反应中表现出了优秀的对映选择性.然而在位阻较小且不含芳环的底物参与的不对称催化反应中,这两类手性磷酸所表现出的对映选择性通常不理想,主要原因在于BINOL的3,3’位取代基和SPINOL的6,6’位取代基向外侧扩展的固有特性使得催化活性位点附近的手性环境相对宽松.为了发展适用于这类底物的手性磷酸催化剂,设计了一种以9,9’-联-10-菲酚(BIFOL)为骨架的1,1’位具有向内侧伸展的芳基取代基的具有紧密手性环境的磷酸,以廉价易得的间二溴苯为起始原料,首先合成关键中间体8-溴-9-菲酚,再通过氧化偶联合成1,1’位溴代的BIFOL,然后利用Suzuki-Miyaura偶联反应引入芳基取代基,最后将芳基取代的BIFOL与三氯氧磷反应的产物磷酰氯水解,经过十二步反应合成了目标分子,并且通过单晶X射线衍射分析确定了其结构.
Chiral phosphoric acids derived from 1,1’-binaphthyl-2,2’-diol(BINOL)and 1,1’-spirobiindane-7,7’-diol(SPINOL)have been widely applied in asymmetric catalysis and displayed excellent enantioselectivities in hundreds of reactions.However,in catalytic asymmetric reactions that involve less sterically hindered nonaromatic substrates,these Br?nsted acids usually provide unsatisfactory enantioselectivities due to the relatively loose chiral environment around the catalytically active site induced by the inherent orientational property of the 3,3’-substituents which extend outwardly.In order to develop chiral phosphoric acids that are compatible with these substrates,9,9’-biphenanthryl-10,10’-diol(BIFOL)-based confined phosphoric acid was designed by introducing two aromatic substituents which extend inwardly onto the 1,1’-positions of BIFOL.By employing cheap and commercially available m-dibromobenzene as starting material,the key intermediate 8-bromophenanthren-9-ol which undergoes oxidative coupling to afford 1,1’-dibromo-9,9’-biphenanthryl-10,10’-diol was first synthesized.After introducing two aryl substituents through Suzuki-Miyaura coupling,the obtained aryl-substituted BIFOL was converted to the targeted molecule by reacting with phosphoryl chloride and hydrolyzing.The structure of the obtained phosphoric acid was confirmed by single crystal X-ray diffraction analysis.
作者
岑守义
张志鹏
Cen Shouyi;Zhang Zhipeng(School of Chemistry and Molecular Engineering,East China University of Science&Technology,Shanghai 200237)
出处
《有机化学》
SCIE
CAS
CSCD
北大核心
2022年第8期2574-2581,共8页
Chinese Journal of Organic Chemistry
基金
国家自然科学基金(No.21702059)
上海市浦江人才计划(No.18PJ1402200)资助项目。
