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1.
Jian‐Xin Ji TerryT.‐L. Au‐Yeung Jing Wu ChiuWing Yip AlbertS.C. Chan 《Advanced Synthesis \u0026amp; Catalysis》2004,346(1):42-44
The first catalytic synthesis of β,γ‐alkynyl α‐amino acid derivatives was achieved by direct addition of terminal alkynes to α‐imino esters in the presence of an Ag(I) salt under mild reaction conditions. 相似文献
2.
Pablo Etayo Ramn Badorrey María D. Díaz‐de‐Villegas Jos A. Glvez 《Advanced Synthesis \u0026amp; Catalysis》2010,352(18):3329-3338
Highly modular chiral amino diol derivatives have been used as organocatalysts in the enantioselective α‐chlorination of cyclic β‐keto esters. Optimization of the catalyst structure and the reaction conditions has allowed the synthesis of optically active α‐chlorinated products with high enantioselectivities (up to 96% ee) using inexpensive commercially available N‐chlorosuccinimide (NCS) as the chlorine source under mild conditions. 相似文献
3.
Jie Li Wei Pan Zheng Wang Xumu Zhang Kuiling Ding 《Advanced Synthesis \u0026amp; Catalysis》2012,354(10):1980-1986
The spiro‐2,2′‐bichroman‐based chiral bisoxazoline ligands (SPANbox) were found to be highly efficient in copper(II)‐ and zinc(II)‐catalyzed asymmetric chlorinations of cyclic β‐keto esters with N‐chlorosuccinimide (NCS) as the chlorination reagent, to give the corresponding α‐chloro‐β‐keto esters in excellent yields in 5–30 min with ee values up to 97%. The copper(II) triflate and zinc(II) triflate complexes of a single SPANbox ligand demonstrated complementary results to each other with respect to the enantioselection, affording both antipodes of the chlorinated product enantiomers with good to excellent optical purities. 相似文献
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An operationally simple and efficient copper‐catalyzed three‐component tandem reaction of terminal alkynes, diazo compounds and amines to yield β‐enamino esters is described. This straightforward protocol takes place rapidly with a wide range of substrates and gives the desired β‐enamino esters in good to excellent yields. Preliminary mechanistic studies suggested that the reaction probably proceeds through Cu‐catalyzed formal C–H insertion to produce an alkynoate intermediate, which was then trapped by amines to give the β‐enamino esters.
6.
Copper‐Catalyzed Addition of Alkylboranes to Iminoacetates: Access to α‐Alkyl Branched α‐Amino Acids
Xinsheng Xiao Wei Zhang Xiaoxia Lu Yuanfu Deng Huangfeng Jiang Wei Zeng 《Advanced Synthesis \u0026amp; Catalysis》2016,358(15):2497-2509
A copper(I)‐catalyzed addition of alkylborane reagents to α‐iminoacetates has been developed to assemble both acyclic and cyclic α‐branched α‐amino carboxylic acid derivatives in good yields. A wide variety of unactivated alkenes are well tolerated in this transformation.
7.
Xianfeng Sun Wei Li Le Zhou Xumu Zhang 《Advanced Synthesis \u0026amp; Catalysis》2010,352(7):1150-1154
A highly efficient strategy for the synthesis of a series of chiral bisaminophosphine ligands was well established with several remarkable features. The synthetic utility of these ligands was explored for rhodium‐catalyzed asymmetric hydrogenations of α‐dehydroamino acid esters. Up to 98% ee values were achieved for the enantioselective synthesis of aminocarboxylic acids and their derivatives, which are very important chiral building blocks for the synthesis of a variety of natural products and biologically active molecules. 相似文献
8.
Chiral phosphoric acids have been identified as highly efficient organocatalysts for the asymmetric transfer hydrogenation of α‐imino esters and amide. Utilizing Hantzsch esters as the hydrogen donor, versatile highly enantioenriched α‐amino esters and their derivatives were obtained with up to 98 % ee. 相似文献
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Xin Zheng Bonan Cao Tang‐lin Liu Xumu Zhang 《Advanced Synthesis \u0026amp; Catalysis》2013,355(4):679-684
The high enantioselective rhodium‐catalyzed hydroformylation of 1,1‐disubstituted allylphthalimides has been developed. By employing chiral ligand 1,2‐bis[(2S,5S)‐2,5‐diphenylphospholano]ethane [(S,S)‐Ph‐BPE], a series of β3‐aminoaldehydes can be prepared with up to 95% enantioselectivity. This asymmetric procedure provides an efficient alternative route to prepare chiral β3‐amino acids and alcohols. 相似文献
11.
The first example of an organocatalytic asymmetric Michael addition of aldehydes to α,β‐unsaturated thiol esters promoted by chiral diphenylprolinol silyl ether is presented. The reaction occurs with good yields, diastereoselectivity and excellent enantioselectivity. 相似文献
12.
Jiefeng Shen Delong Liu Qianjin An Yangang Liu Wanbin Zhang 《Advanced Synthesis \u0026amp; Catalysis》2012,354(17):3311-3325
(2S,3aR,7aS)‐Perhydroindolic acid, the key intermediate in the synthesis of trandolapril, and its trans‐isomers, were readily prepared. These proline‐like molecules are unique in that they contain a rigid bicyclic structure, with two hydrogen atoms trans to each other at the bridgehead carbon atoms. These molecules were used successfully as chiral organocatalysts in asymmetric domino Michael addition/cyclization reactions of aldehyde esters with β,γ‐unsaturated α‐keto esters. They proved to have excellent catalytic behavior, allowing for the synthesis of multi‐substituted, enantiomerically enriched hemiacetal esters. Under optimal conditions (using 10 mol% catalyst loading), a series of β,γ‐unsaturated α‐keto esters was examined with up to 99% de, ee and yield, respectively. Additionally, the enantiomerically enriched hemiacetal esters could be readily transformed into their corresponding bioactive pyrano[2,3‐b]pyrans (possessing a multi‐substituted bicyclic backbone). 相似文献
13.
Jianheng Ye Chao Wang Lin Chen Xinjun Wu Li Zhou Jian Sun 《Advanced Synthesis \u0026amp; Catalysis》2016,358(7):1042-1047
Catalytic asymmetric reduction of N‐unsubstituted β‐enamino esters represents a major challenge for asymmetric catalysis. In this paper, the first organocatalytic system that could be used for the asymmetric hydrosilylation of N‐unsubstituted β‐enamino esters has been developed. Using N‐tert‐butylsulfinyl‐L ‐proline‐derived amides and L ‐pipecolinic acid‐derived formamides as catalyst, a broad range of β‐aryl‐ and β‐alkyl‐substituted free β‐amino esters could be prepared with high yields and enantioselectivities. The practicality was illustrated by the gram‐scale asymmetric synthesis of ethyl (R)‐3‐amino‐3‐phenylpropanoate and isopropyl (S)‐3‐amino‐4‐(2,3,5‐trifluorophenyl)butanoate. The resulting product can be smoothly transformed to the FDA approved medicines dapoxetine and sitagliptin in a short synthetic route.
14.
Marco Lombardo Alessandra Gualandi Filippo Pasi Claudio Trombini 《Advanced Synthesis \u0026amp; Catalysis》2007,349(3):465-468
An efficient cobalt(I )‐catalysed Reformatsky reaction using α‐chloro esters has been developed. The catalyst is prepared by reducing the cobalt(II ) chloride (5 %)/1,2‐bis(diphenylphosphino)ethane (dppe)(5 %)/zinc iodide (10 %) system with zinc metal in acetonitrile in the presence of both the α‐chloro ester and the carbonyl compound; good to excellent conversions to β‐hydroxy esters are obtained at room temperature in 2.5 h. 相似文献
15.
ZsuzsannaCs. Gyarmati Arto Liljeblad Gyula Argay Alajos Klmn Gbor Bernth LiisaT. Kanerva 《Advanced Synthesis \u0026amp; Catalysis》2004,346(5):566-572
Racemic cis‐10‐azatetracyclo[7.2.0.12,6.14,8]tridecan‐11‐one was prepared from homoadamant‐4‐ene by chlorosulfonyl isocyanate addition. The transformation of the β‐lactam to the corresponding β‐amino ester followed by Candida antarctica lipase A‐catalyzed enantioselective (E>>200) N‐acylation with 2,2,2‐trifluoroethyl butanoate afforded methyl (1R,4R,5S,8S)‐5‐aminotricyclo[4.3.1.13,8]undecane‐4‐carboxylate and the (1S,4S,5R,8R)‐butanamide with>99% ee at 50% conversion. Alternatively, transformation of the β‐lactam to the corresponding N‐hydroxymethyl‐β‐lactam and the following Pseudomonas cepacia (currently Burkholderia cepacia) lipase‐catalyzed enantioseletive O‐acylation provided the (1S,4S,6R,9R)‐alcohol (ee=87%) and the corresponding (1R,4R,6S,9S)‐butanoate (ee>99%). In the latter method, competition for the enzyme between the (1R,4R,6S,9S)‐butanoate, 2,2,2‐trifluoroethyl butanoate and the hydrolysis product, butanoic acid, tended to stop the reaction at about 45% conversion and finally gave racemization in the (1S,4S,6R,9R)‐alcohol with time. 相似文献
16.
Luca Deiana Gui‐Ling Zhao Shuangzheng Lin Pawel Dziedzic Qiong Zhang Hans Leijonmarck Armando Crdova 《Advanced Synthesis \u0026amp; Catalysis》2010,352(18):3201-3207
The first example of a highly enantioselective organocatalytic aziridination of α‐substituted α,β‐unsaturated aldehydes is presented. The reaction is catalyzed by simple chiral amines and gives access to highly functional terminal azirdines containing an α‐tertiary amine stereocenter in high yields and enantiomeric ratios (95.5:4.5–98:2). 相似文献
17.
Huiling Geng Xiaowei Zhang Mingxin Chang Le Zhou Wenjun Wu Xumu Zhang 《Advanced Synthesis \u0026amp; Catalysis》2011,353(16):3039-3043
A highly efficient and enantioselective hydrogenation of unprotected β‐ketoenamines catalyzed with ruthenium(II) dichloro{(S)‐(−)‐2,2′‐bis[di(3,5‐xylyl)phosphino]‐1,1′‐binaphthyl}[(2S)‐(+)‐1,1‐bis(4‐methoxyphenyl)‐3‐methyl‐1,2‐butanediamine] {Ru[(S)‐xylbinap][(S)‐daipen]Cl2} has been successfully developed. This methodology provides a straightforward access to free γ‐secondary amino alcohols, which are key building blocks for a variety of pharmaceuticals and natural products, with high yields (>99%) and excellent enantioselectivities (up to 99% ee) in all cases. 相似文献
18.
Wenjing Xia Hong Yao Dan Liu Linxiang Zhao Yu Zhou Hong Liu 《Advanced Synthesis \u0026amp; Catalysis》2016,358(11):1864-1869
Herein, we disclose the N‐heterocyclic carbene (NHC)‐catalyzed [3+3] annulation of challenging esters with methyl ketoimines for the highly enantioselective synthesis of intriguing δ‐lactams featuring various substituent patterns. The annulation occurs under mild conditions and offers good tolerance, good yields and excellent enantioselectivities. The six‐membered heterocyclic products are valuable for the synthesis of bioactive molecules.
19.
Yakun Wang Hang Yin Hai Qing Jingnan Zhao Yufeng Wu Qingwei Meng 《Advanced Synthesis \u0026amp; Catalysis》2016,358(5):737-745
The highly catalytic asymmetric α‐hydroxylation of β‐indanone esters and β‐indanone amides using peroxide as the oxidant was realized with a new C‐2′ substituted Cinchona alkaloid derivatives. The two enantiomers of α‐hydroxy‐β‐indanone esters could be obtained by simply changing the oxidant. This protocol allows a convenient access to the corresponding α‐hydroxy‐β‐indanone esters and α‐hydroxy‐β‐indanone amides with up to 99% yield and 98% ee.
20.
Zugui Shi Peiyuan Yu Pei Juan Chua Guofu Zhong 《Advanced Synthesis \u0026amp; Catalysis》2009,351(17):2797-2800
In the presence of the readily available quinine‐derived catalyst 4d , highly diastereo‐ and enantioselective Mannich reactions of tosyl‐protected imines and α‐isothiocyanato imides proceeded to afford the protected α,β‐diamino acids, useful building blocks for natural products and biologically active compounds, in good to excellent yields. 相似文献