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1.
1,2-Bisphosphines have been identified as one class of important and powerful chiral ligands in asymmetric catalysis with transition metals. Herein, a copper(I)-catalyzed asymmetric hydrophosphination of α,β-unsaturated phosphine sulfides was developed with the assistance of “soft–soft” interaction between copper(I)-catalyst and the phosphine sulfide moiety, which afforded 1,2-bisphosphine derivatives with diversified electronic nature and steric hindrance in high to excellent yields with high to excellent enantioselectivity. Moreover, the challenging catalytic asymmetric hydrophosphination/protonation reaction was achieved with excellent enantioselectivity. Strikingly, the dynamic kinetic resolution of racemic diarylphosphines was also successfully carried out with high to excellent diastereo- and enantioselectivities. Interestingly, the nucleophilic copper(I)-diphenylphosphide species was characterized by 31P NMR spectrum and mass spectrum. At last, three products were transformed to chiral 1,2-bisphosphines, which were employed as ligands in Rh-catalyzed asymmetric hydrogenation of α-amino-α,β-unsaturated ester. The α-amino acid derivative was produced in high enantioselectivity, which demonstrated the utility of the present methodology.  相似文献   

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Chiral 2,3‐allenols were constructed through copper(I)‐catalyzed asymmetric direct alkynylogous aldol reaction. With aromatic and heteroaromatic aldehydes, the alkynylogous aldol reaction with (R)‐DTBM‐SEGPHOS as the ligand proceeded smoothly to furnish the products in excellent regioselectivity with good to high diastereoselectivity and excellent enantioselectivity. In the cases of aliphatic aldehydes, esters of but‐2‐yn‐1‐ol as the substrates and (R,R)‐Ph‐BPE as the ligand were found to be crucial to get good to high regio‐ and diastereoselectivity. The produced chiral 2,3‐allenols are easily transformed into synthetically useful 2‐furanones through cyclization. Finally, the developed method was successfully applied in the rapid synthesis of two chiral intermediates toward the synthesis of two pharmaceutically active compounds that have been proposed for the treatment of neurological disorders.  相似文献   

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三氟甲基磺酸铜 [Cu(OTf) 2 ]与各种手性磷氮配体络合催化不对称合成已取得了巨大进展 .详细评述了近五年来该类手性铜催化剂在各种不对称催化反应中的最新应用  相似文献   

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SimplePhos ligands represent a novel class of monodentate chiral ligands based on a chiral amine moiety and flexible diaryl groups on the phosphorous atom. They can be easily prepared by two different pathways and they can be highly functionalised. Herein we report the copper‐catalysed asymmetric conjugate addition of diethyl zinc and trialkylaluminium reagents with SimplePhos ligands, which gives high enantioselectivity with cyclic enones, acyclic enones and nitro‐olefins, with up to 98.6 % ee. Of particular interest is the reaction of trialkylaluminium reagents with a wide range of 3‐substituted enones, thus allowing the formation of stereogenic quaternary carbon centres.  相似文献   

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The highly enantioselective alkynylation of isatins, catalyzed by a bifunctional guanidine/CuI catalyst under mild reaction conditions, is described. The reaction is broad in scope with respect to alkyl/aryl‐substituted terminal alkynes and substituted isatins, thus affording bioactive propargylic alcohols in excellent yields and enantioselectivities.  相似文献   

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An N,N′‐dioxide/scandium(III) complex catalyzed, highly efficient conjugate addition of malonic esters to enynes is described. A range of trisubstituted 1,2‐allenyl ketones were obtained in high yields (up to 99 %) with good d.r. (up to 95/5) and excellent ee values (97 %–99 %). Moreover, the products could be easily transformed into chiral furan and 5‐hydroxypyrazoline derivatives, both of which are important skeletons of many biologically active compounds and pharmacologicals.  相似文献   

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By introducing a disposable activating substituent at C‐3, the asymmetric 1,4‐addition to a notoriously unreactive 2‐substituted chromenone was achieved with high levels of (2R)‐stereoselectivity in the presence of a chiral CuI‐phosphoramidite complex as a catalyst. This paved the way for an efficient and conceptually novel synthesis of (R,R,R)‐α‐tocopherol from readily available starting materials.  相似文献   

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手性药物的酶催化不对称定向合成   总被引:3,自引:0,他引:3  
手性药物目前已成为国际上新药研究的热点。手性药物及其中间体的酶催化定向合成与传统的有机合成反应相比,所需条件温和,无需强酸强碱、高温高压等极端条件,可大大降低对设备的要求,同时具备反应速度快、立体选择性高等优势,而且对环境污染小,属于绿色合成技术,因而成为制备手性化合物的最有前景的方法之一。本文主要介绍了手性药物的酶催化不对称定向合成的方式、催化机理及应用,并引入了一些最新进展情况。  相似文献   

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A catalytic protocol for the diastereoselective synthesis of anti‐1,2‐hydroxyboronates is described. The process provides access to secondary alkyl organoborons. The deborylative 1,2‐addition reactions of alkyl 1,1‐diborons proceed in the presence of a silver(I) salt with either KOtBu or nBuLi as an activator. The catalytic diastereoselective protocol can be extended to aryl, alkenyl, and alkyl aldehydes with up to 99:1 d.r.  相似文献   

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李晓光  王立新  周其林 《中国化学》2002,20(11):1445-1449
IntroductionAsymmetriccatalyticcyclopropanationofolefinswithdiazocompoundsisoneofthemostusefulmethodsforthesynthesisofchiralcyclopropanes .1Anumberofefficientchiralligands ,particularlybisnitrogenligands ,havebeendeveloped ,andexcellentenantioselectiviti…  相似文献   

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不对称催化反应在手性农药不对称合成中的一些应用   总被引:6,自引:0,他引:6  
近十多年来,不对称催化反应在单一手性农药研发中的应用渐渐引起人们的关 注,结合自己的研究对这一领域的不对称催化反应及手性催化剂的发展进行了归纳 总结。  相似文献   

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