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(S)-(1-Benzylpyrrolidin-2-yl)diphenylmethanol and cinchonine were evaluated as promotors in the asymmetricadditions of phenylacetylene to ketones,in order to prepare chiral propargylic alcohols.Good yields(up to 89%)and moderate enantioselectivities(up to 77.9% ee)were achieved.Addition of Ti(OPr-i)_4 can significantly improvethe enantioselectivity of the reaction. 相似文献
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KANG Yong-Feng LIU Lei YAN Wen-Jin XU Zhao-Qing ZHOU Yi-Feng HAN Zhi-Jian NI Ming DA Chao-Shan WANG Rui 《有机化学》2004,24(Z1):163
Development of new or improved methods for the asymmetric preparation of chiral propargylic alcohols has gained considerable significance during the past years because they are useful building blocks for the synthesis of many biologically active compounds and natural products.[1] A series of chiral tridentate ligands were conveniently synthesized from amino acids with good yields (Scheme 1).[2] A preliminary study of the enantioselective alkynylation of benzaldehyde catalyzed by this chiral tridentate ligand was carried out and up to 83% ee of chiral propargyl alcohols was obtained (Table 1 ). A further investigation of the tridentate ligand is currently underway. 相似文献
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Peptide Deravatives as New Chiral Ligands for Enantioselective Phenylacetylene Addition to Aldehydes
ZHOU Yi-Feng GAO Yan-Feng KANG Yong-Feng HAN Zhi-Jian YAN Wen-Jin NI Ming WANG Rui 《有机化学》2004,24(Z1):162
The asymmetric addition of alkynylzinc to aldehydes is an important method of synthesizing chiral propargyl alcohols, which are important precursors to many chiral organic compounds. Recently, many significant chiral ligands in this area have been disclosed.[1] Use of a short peptide as a catalyst would allow expansion beyond the (still uncharted) repertoire of single amino acids, while conserving the advantages of a small molecule catalyst. To the best of our knowledge,no results of peptide derivatives as chiral ligands in this reaction has been disclosed to date.[2] Herein, we report the initial results of peptide derivatives, which have been used directly as a chiral ligand in this reaction (Scheme 1). 相似文献
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Asymmetric C-C bond forming reactions are of prime importance in modem synthetic organic chemistry. The use of chiral amino alcohol ligands is widespread in this area.[1] Herein, we describe the synthesis of N-sulfonylated amino alcohols 1~4 and enantioselective addition of diethylzinc to aldehydes was carried out employing titanium(Ⅳ) complexes 1~4. 相似文献
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The synthesis of several novel three-dentate sulfonamide alcohol ligands is described, starting from camphorsulfonyl chloride. The influence of temperature and ligand structure on the asymmetric addition of dietylzinc to aromatic aldehydes has been studied. Enantioselectivities up to 76% have been obtained. 相似文献
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《合成通讯》2013,43(13):1819-1823
Abstract The chiral oxazolidine ligand can catalyze the enantioselective addition of diethylzinc to aromatic aldehydes at room temperature with high enantioselectivity (98–99% ee). The conditions for this catalytic process are both mild and simple as compared with the same kind catalyst. 相似文献
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Yanagisawa A Kageyama H Nakatsuka Y Asakawa K Matsumoto Y Yamamoto H 《Angewandte Chemie (International ed. in English)》1999,38(24):3701-3703
Catalytic asymmetric allylation of aldehydes with allylic trimethoxysilanes was achieved with the p-Tol-BINAP small middle dotAgF complex as catalyst [Eq. (a); p-Tol-BINAP=2,2'-bis(di-p-tolylphosphanyl)-1,1'-binaphthyl)]. High anti and enantioselectivities were obtained in the reaction with crotyltrimethoxysilane, irrespective of the configuration at the double bond. 相似文献
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Homogeneous asymmetric catalysis is one of the most important developments in chemistry in the past several decades. Attachment of chiral ligands to a polymeric support offers important advantages such as facilitated workup procedures, easy recovery and reuse of the catalyst in catalytic reactions. Various chiral ligands supported on polymer have been used as catalysts. 相似文献
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Qian Yong XU Guo Xing WANG Xin Fu PAN* Department of Chemistry National Laboratory of Applied Organic Chemistry Lanzhou University Lanzhou 《中国化学快报》2001,(5)
One of the most important and fundamental synthetic procedures for the establishment of a carbon-carbon bond stereoselectively is the enantioselective addition of organometallic reagents to aldehydes affording chiral secondary alcohols1. In this process, a frequently used method is to perform the reaction in the presence of a chiral ligand such as amino alcohol2. Here, we first report that two new chiral ligands3, which were readily available by the reaction of chiral ketone with lithiated 2-m… 相似文献
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WANG Jie WU Shijie WANG Xiaoke LI Longfei YANG Kan ZHU Huajie LI Wan LIU Li 《高等学校化学研究》2019,35(4):604-608
Allylation of bulky-substituted aromatic aldehydes with allyltrichlorosilanes were catalyzed by axial biscarboline N.N-dioxide esters with high enaiitioselectivities up to 92% e.e. for l-(4-chlorophenyl)-9-methyl-9Hpyrido[3,4-b]indole-3-carbaldehyde and 90% e.e.for 1-(3-methoxyphenyl)-9-methyl-9H-pyrido[3,4-b]indole-3-carbaldehyde, respectively.Total 22 aldehydes were tested with good yields and enantioselectivities.Catalyst 4f exhibited good catalytic enantioselectivity. 相似文献
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合成了一类光学纯的7,7′-二取代联二萘酚, 并将其用在乙基锌对醛的对映选择性加成, 以54%~88%的产率和最高88%的对映选择性得到了光学活性的1-苯基-1-丙醇. 相似文献
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高分子负载金属络合物催化烯烃对映选择环氧化的研究 总被引:8,自引:0,他引:8
综述了近年来高分子负载金属络合物催化烯烃对映选择环氧化的研究进展,着重阐述了有机高分子和无机高分子负载金属络合物催化剂的催化活性,并就如何设计具有高催化活性和高对映选择性的高分子负载金属络合物催化剂提出了一些建议。 相似文献
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Ying‐Ni Cheng Dr. Hsyueh‐Liang Wu Dr. Ping‐Yu Wu Ying‐Ying Shen Prof. Dr. Biing‐Jiun Uang 《化学:亚洲杂志》2012,7(12):2921-2924
An effective catalytic system that imparts high enantioselectivity has been disclosed for the synthesis of optically active alcohols, which may undergo further chemical transformations. The enantioselective alkylation of aldehydes with dialkylzincs to afford the corresponding optically active alcohols with excellent enantioselectvities has been achieved in the presence of 0.1–0.5 mol % of the camphor‐derived chiral ligand (?)‐2‐exo‐morpholinoisobornane‐10‐thiol (MITH) ( 1 ) at room temperature or at 0 °C. 相似文献
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Alkoxy- and aryloxy-organotitanium compounds 2–4 derived from (S)-2-methyl-1-butanol, (R)-2-butanol, (-)-menthol, quinine, cinchonine, and (S)-1.1′-binaphthol are added to aromatic aldehydes to give optically active alcohols 5–10 in enantioselectivities of up to 88% e. e., with nucleophilic transfer of methyl, phenyl, and 1-naphthyl groups. The Tables 1–3 list the effects of varying the reagents, the substrates, and the reaction conditions of the new asymmetric synthesis. 相似文献