Syntheses and Applications of Optically Active Organoantimony (III) Compounds to Asymmetric Reaction.

本论文旨在合成新型Sb手性C_2对称光学活性有机锑化合物，并对其结构、反应活性以及作为手性配体在不对称合成中的应用进行研究. Sb-手性和C_2-对称光学活性有机锑（Ⅲ）化合物的合成与拆分：（a）制备第15族有机金属化合物的最直接的方法是用格氏试剂或有机锂试剂处理适当的金属卤化物（R_nMX_（3-n），> M=P、As、Sb和Bi），使卤素基团亲核取代。然而，由于R_nMX_上的卤素基团作为离去基团具有很高的反应活性，该方法在M-手性化合物的制备中已被证明是不令人满意<3-n>的。针对这一问题，我们用乙炔基取代卤素基团，找到了一种新的分步亲核试剂制备Sb-手性有机锑化合物的通用方法 ...更多信息 通过双乙炔基锑烷中间体取代三溴锑烷。(b)尽管阻转异构的1，1-萘基核心是一个稳定增长的高效C_2对称手性辅基家族的母体骨架，并且已经报道了各种磷和砷化合物，如BINAP，MOP，BINAs和BINAPAs，但还没有光学活性的铋类似物。本文报道了由2，2 ′-二溴代衍生物经叔丁基锂处理制得的2，2 ′-二硫代-1，1 ′-联萘中间体与金属二卤化物（ArSbBr_2、ArBiBr_2）反应，得到相应的联萘衍生物（BINASb和BINABi），并以光学活性钯配合物为拆分剂进行拆分。另外，用ArSbBr_2处理光学活性的2，2 ′-二硫代-1，1 ′-联萘中间体，导致环闭合，得到光学活性的7-芳基二萘并[2，1-B，1 ′，2 ′-d]锑，这是第一个分离的光学活性二萘并杂环化合物.用于不对称合成的光学活性有机锑（III）化合物的评价：对以上获得的光学活性有机锑配体进行不对称反应的评价。结果表明，光学活性有机锑化合物是不对称反应的有效配体。如过渡金属催化的前手性酮的对映选择性还原和rac-1，3-二苯基-2-丙烯基乙酸酯与丙二酸二甲酯的不对称烯丙基取代反应。少

This study was performed to synthesize new Sb-chiral and C_2-symmetric optically active organoantimony (Sb) compounds and to clucidate their chemical propertics such as structural fcature, reactivity, and applicability as a chiral ligand to asymmetric syntheses.1. Syntheses and resolutions of Sb-chiral and C_2-symmetric optically active organoantimony (III) compounds : (a) The most straightforward method for the preparation of group 15 organometallic compounds is the nucleophilic displacement of the halogen group on appropriate metal halides (R_nMX_<3-n, > M=P.As.Sb.and Bi) by treatment with Grignard or organolithium reagents. However, this method has been proved to be unsatisfactory for the preparation of M-chiral compounds, because the halogen moiety on R_nMX_<3-n> is highly reactive as leaving groups. To solve this problem, we used ethynyl groups instead of halogen groups, and found a new general method for the preparation of Sb-Chiral organoantimony compounds by stepwise nucleophil … More ic displacement of tribromostibane via a bisethynyl stibane intermediate. (b) Althought, the atropisomeric 1, 1-naphthyl core is the parent framework of a steadily increasing family of C_2-symmetric chiral auxiliaries of high efficiency and a variety of phosphorous and arsenic compounds, such as BINAP, MOP, BINAs, and BINAPAs have been reported, no optically active bismuth analogues have been known. We demonstrated that the reaction of 2, 2'-dilithio-1, 1'-binaphthyl intermediate, prepared from 2, 2'-dibromo derivative by treatment with t-BuLi, with metal dihalides (ArSbBr_2, ArBiBr_2) afforded the corresponding binaphthyl dedivatives (BINASb and BINABi) which can be resolved by use of optically active Pd-complex as a resolving agent. Otherwise, treatment of the optically active 2, 2'-dilithio-1, 1'-binaphthyl intermediate with ArSbBr_2 resulted in ring closure to afford optically active 7-aryldinaphtho[2, 1-b, 1', 2'-d] stiboles which is the first isolated example of optically active dinaphthoheterols.2. Evaluation of optically active organoantimony (III) compounds for asvmmetric syntheses : Evaluation of the optically active organoantimony ligands obtained above for asymmetric reactions was made. The results show that the optically active organoantimony compounds were effective ligands for asymmetric reactions. such as transition metal catalyzed enantioselective reduction of prochiral ketones and asymmetric allylic substitution reaction of rac-1, 3-diphenyl-2-propenyl acetate with dimethyl malonate. Less