手性Br（？）nsted酸催化的吲哚与α，β-不饱和三氟甲基酮的傅—克烷基化反应
|
摘要
吲哚类化合物在自然界中广泛存在,具有一定的生理活性。以吲哚核为原料合成具有生理活性的天然产物并将其应用于活性筛选,一直以来都是吲哚化学的研究核心。在各种吲哚衍生物中,3-位取代的吲哚在天然产物全合成和药物分子靶标设计中是一类重要的骨架。不对称的傅-克烷基化反应是构建吲哚类骨架的一种有效办法。
三氟甲基化合物具有许多独特的理化性质及生物活性,广泛应用于农药、医药、染料以及功能材料等领域。三氟甲基化反应是制备含氟有机化合物的重要方法之一。由于氟特有的化学性质,因此在芳香族化合物的芳环上引入三氟甲基后,其性能会得到大幅度的改善。目前,该类化合物已广泛地应用于多个领域。
本文主要研究了在手性Br?nsted酸催化作用下,吲哚与α,β-不饱和三氟甲基酮的傅-克烷基化反应,合成了一系列新的含氟手性化合物,并对部分产物进行了进一步的不对称还原转化,获得了较高的产率和很好的对映选择性。在这一反应中,分别对催化剂、溶剂、反应温度等诸多影响因素进行了探索,确定了最佳反应条件,最终选定以21e(10%)为催化剂、以ClCH2CH2Cl/CH3CN=1:1的混合溶剂作为反应介质,在-20oC下进行反应。在最优条件下,我们考察了手性磷酸催化的α,β-不饱和三氟甲基酮不对称傅-克反应的底物适用范围,能得到最高99%的收率和88%的对映选择性。通过红外光谱、核磁共振碳谱、核磁共振氢谱对所合成的化合物的结构进行了鉴定。
Indoles are a class of Heterocycle with important physiological Function and potent pharmacological activity. The development of new efficient, selective and green synthetic methods of the 3-substituted indoles derivatives has attracted sustained attention in organic synthesis, due to their important biological activities and key role as versatile building bocks in the synthesis of natural products and therapeutic agent. Therefore, asymmetric Friedel–Crafts (F-C) alkylation has become a powerful strategy for the construction of indoles architectures.
Due to their special physic-chemical and biological properties, trifluoromethylated compounds found wide applications in the fields of agrchemicals, pharmaceutical, dyes and functional materals. Trifluoromethylation is the key step in the synthesis of organo-fluorine compounds. Because of the unique characteristics of fluorine. There will be a significant improvement in properties for aromatic compound, if thifluoromethyl group is introduced into its structures. Untill now, there has already been an extensive application for this kind of aromatic compounds.
In this paper, Friedel-Crafts Alkylation of Indoles withα,β-Unsaturated Trifluoromethyl Ketones proceeded by way of a Br?nsted acid-catalyzed. We had Synthesized a series of new trifluoromethylated chiral compounds and had obtained good yields with high enantioselectivity. In this reaction, we examined comprehensive experimental factors, such as catalysts, solvents, temperatures. Good results were observed. In the best condition we could obtain 99% yield and 88% ee. The structures of the new products had been determined by IR, 1H NMR, 13C NMR.
三氟甲基化合物具有许多独特的理化性质及生物活性,广泛应用于农药、医药、染料以及功能材料等领域。三氟甲基化反应是制备含氟有机化合物的重要方法之一。由于氟特有的化学性质,因此在芳香族化合物的芳环上引入三氟甲基后,其性能会得到大幅度的改善。目前,该类化合物已广泛地应用于多个领域。
本文主要研究了在手性Br?nsted酸催化作用下,吲哚与α,β-不饱和三氟甲基酮的傅-克烷基化反应,合成了一系列新的含氟手性化合物,并对部分产物进行了进一步的不对称还原转化,获得了较高的产率和很好的对映选择性。在这一反应中,分别对催化剂、溶剂、反应温度等诸多影响因素进行了探索,确定了最佳反应条件,最终选定以21e(10%)为催化剂、以ClCH2CH2Cl/CH3CN=1:1的混合溶剂作为反应介质,在-20oC下进行反应。在最优条件下,我们考察了手性磷酸催化的α,β-不饱和三氟甲基酮不对称傅-克反应的底物适用范围,能得到最高99%的收率和88%的对映选择性。通过红外光谱、核磁共振碳谱、核磁共振氢谱对所合成的化合物的结构进行了鉴定。
Indoles are a class of Heterocycle with important physiological Function and potent pharmacological activity. The development of new efficient, selective and green synthetic methods of the 3-substituted indoles derivatives has attracted sustained attention in organic synthesis, due to their important biological activities and key role as versatile building bocks in the synthesis of natural products and therapeutic agent. Therefore, asymmetric Friedel–Crafts (F-C) alkylation has become a powerful strategy for the construction of indoles architectures.
Due to their special physic-chemical and biological properties, trifluoromethylated compounds found wide applications in the fields of agrchemicals, pharmaceutical, dyes and functional materals. Trifluoromethylation is the key step in the synthesis of organo-fluorine compounds. Because of the unique characteristics of fluorine. There will be a significant improvement in properties for aromatic compound, if thifluoromethyl group is introduced into its structures. Untill now, there has already been an extensive application for this kind of aromatic compounds.
In this paper, Friedel-Crafts Alkylation of Indoles withα,β-Unsaturated Trifluoromethyl Ketones proceeded by way of a Br?nsted acid-catalyzed. We had Synthesized a series of new trifluoromethylated chiral compounds and had obtained good yields with high enantioselectivity. In this reaction, we examined comprehensive experimental factors, such as catalysts, solvents, temperatures. Good results were observed. In the best condition we could obtain 99% yield and 88% ee. The structures of the new products had been determined by IR, 1H NMR, 13C NMR.
引文
[1]盛益飞,张安将,郑晓建,游书力.有机催化的不对称傅克烷基化反应.有机化学报, 2008,28 (4):605-616.
[2] C. Friedel, J. M. Crafts. Bull. Soc. Chim. Fr. 1877, 27, 530.
[3] For reviews: a)王以,丁奎岭.催化不对称Friedel-Crafts反应.有机化学, 2001, 21, 763. b) Y. Wang, K. L. Ding. Chemtracts. 2001, 14, 610.c) M. Bandini, A. Melloni, Umani-Ronchi. New Catalytic Approaches in the Stereoselective Friedel–Crafts Alkylation Reaction. Angew. Chem. Int. Ed. 2004, 43, 550.
[4] J. F. Austin, D. W. C. MacMillan. Enantioselective Organocatalytic Indole Alkylatio Design of a New and Highly Effective Chiral Amine for Iminium Catalysis. J. Am. Chem. Soc. 2002, 124, 1172.
[5] K. B. Jensen, J. Thorhauge, R. G. Hazell, K. A. J?rgensen. Catalytic Asymmetric Friedel– Crafts Alkylation ofα,β-Unsaturated a-Ketoesters: Enantioselective Addition of Aromatic C-H Bonds to Alkenes. Angew. Chem. Int. Ed. 2001, 40, 160.
[6] J. Zhou, Y. Tang. Sidearm Effect: Improvement of the Enantiomeric Excess in the Asymmetric Michael Addition of Indoles to Alkylidene Malonates. J. Am. Chem. Soc. 2002, 124, 9030-9031.
[7] G. Desimoni, G. Faita, M. Toscanini, M Boiocchi. Asymmetric Friedel–Crafts Alkylation of Indoles with Methyl (E)-2-Oxo-4-aryl-3-butenoates Catalyzed by Sc(OTf)3/pybox. Chem. Eur. J. 2008, 14, 3630–3636.
[8] M. Bandini, M. Fagioli, P. Melchiorre, A. Melloni, A. Umani-Ronchi. Catalytic enantioselective conjugate addition of indoles to simpleα,β-Unsaturated ketones. Tetrahedron Letters. 2003, 44, 5843–5846.
[9] For books and reviews: a) A. Berkessel, H. Groger. Asymmetric Organocatalysis, Wiley-VCH, Meinheim, 2004. b) P. I. Dalko, L. Moisan. In the Golden Age of Organocatalysis. Angew. Chem. Int. Ed.2004, 43, 5138.c) J. Seayad,; B.List. Asymmetric organocatalysis.Org. Biomol. Chem. 2005, 3, 719.d) H. Pellissier. Tetrahedron. Asymmetric organocatalysis. 2007, 63, 9267.e) P. I. Dalko.Enantioselective Organocatalysis, Wiley-VCH. Weinheim,2007.
[10] J. F. Austin, D. W. C. MacMillan. Enantioselective Organocatalytic Indole Alkylatio Design of a New and Highly Effective Chiral Amine for Iminium Catalysis. J. Am. Chem. Soc. 2002, 124, 1172.
[11] C.-F. Li, Y.-J. Cao, X.-P. Liu,W.-J. Xiao. Enantioselective Organocatalytic Intramolecular Ring-Closing Friedel-Crafts-Type Alkylation of Indoles. Org. Lett. 2007, 9, 1847.
[12] N. A. Paras, D. W. C. MacMilan. The Enantioselective Organocatalytic 1,4- Addition of Electron-Rich Benzenes toα,β-Unsaturated Aldehydes. J. Am. Chem. Soc. 2002, 124, 7894.
[13] W.Zhou, L.-W. Xu , L. Li, L.Yang, C.-G. Xia. Enantioselective Michael-Type Friedel–Crafts Reactions of Indoles to Enones Catalyzed by a Chiral Camphor- Based Br?nsted Acid. Eur.J.Org.Chem.2006,71,5225.
[14] W. Chen, W. Du, L.Yue, R. Li, Y. Wu, L.-S. Ding, Y,-C. Chen. Organocatalytic enantioselective indole alkylations ofα,β-unsaturated ketones. Org.. Biomol. Chem. 2007, 5, 816.
[15] Giuseppe Bartoli, Marcella Bosco, Armando carlone, Fabio Pesciaioli, Letizia Sambri,and Paolo Melchiorre, Organocatalytic Asymmetric Friedel-Crafts . Org. Lett. 2007, 9, 1403.
[16] H.-Y. Tang, A.-D. Lu, Z.-H. Zhou, G.-F.Zhao, L.-N. He, C.-C. Tang. Chiral Phosphoric Acid Catalyzed Asymmetric Friedel–Crafts Alkylation of Indoles with Simpleα,β-Unsaturated Aromatic Ketones. Eur. J. Org. Chem. 2008, 1406–1410.
[17] W. Zhuang, T. B. Poulsen, K.A. J?rgensen. A versatile catalyst for asymmetric reactions of carbonyl groups working purely by activation through hydrogen bonding: Mukaiyama-aldol, hetero Diels–Alder and Friedel–Crafts reactions.Org. Biomol. Chem. 2005, 3, 3284.
[18] H.-M.Li, Y.-Q. Wang, L. Deng. Enantioselective Friedel?Crafts Reaction of Indoles with Carbonyl Compounds Catalyzed by Bifunctional Cinchona Alkaloids.Org. Lett. 2006, 8, 4063.
[19] W. Zhuang, R. G. Hazell, K.A. J?rgensen. Enantioselective Friedel–Crafts type addition of indoles to nitro-olefins using a chiral hydrogen-bonding catalyst– synthesis of optically active tetrahydro-β-carbolines. Org. Biomol. Chem., 2005, 3, 2566– 2571.
[20] R. P. Herrera, V. Sgarzani, L. Bemardi, A. Ricci. Catalytic Enantioselective Friedel-Crafts Alkylation of Indoles with Nitroalkenes by Using a Simple Thiourea Organocatalyst. Angew. Chem. Int. Ed. 2005, 44, 6576.
[21] E. M. Flemimg, T. McCabe,S. J. Connon. Novel axially chiral bis-arylthiourea-based organocatalysts for asymmetric Friedel-Crafts type reactions. Tetrahedron Lett. 2006, 47, 7037.
[22] K. Johns, G.. Stead. Fluoroproducts-the extremophiles. J. Fluorine. Chem. 2000, 104, 5-18.
[23] a) F. M. D. Ismail, Important fluorinated drugs in experimental and clinical use. J. Fluorine. Chem. 2002, 118, 27-33. b) C. Isanbor, D. O’Hagan, Fluorine in Medical Chemistry: A Review of anti-cancer Agents. J. Fluorine. Chem. 2006, 127, 303-319.
[24]卿凤翎,邱小龙,有机氟化学,北京:科学出版社, 2007, p135.
[25] a) F. Camps, J. Coll, G. Fabrias, A. Guerrero, Synthesis of Dienic Fluorinated Analogs of Insect Sex Pheromones. Tetrahedron 1984, 40, 2871-2878. b) E. A. Hallinan, J. Fried, 2,2-Difluoro-3-Hydroxyesters by Reformatsky Reaction. Tetrahedron 1984, 25, 2301-2302. c) D. Seyfeth, R. M. Simon, D. J. Sepelak, H. A. Klein, gem-(Difluoroallyl)lithium: Preparation by Lithium-Halogen Exchange and Utilization in Organosillicon and Organic Synthesis. J. Am. Chem. Soc. 1983, 105, 4634-4639. d) F. Tian, V. Kruger, W. R. Dolhier, Q. Y. Chen, et al, A Novel and Highly Efficient Synthesis of gem-Difluorocyclopropanes. Org. Lett. 2000, 2, 563-564. e) B. Jiang, Y.–Y. Xu, Trifluoroisopropenylzinc Reagent as A Usefulα-(Trifluoromethyl)ethenyl Carbanion Synthetic Equivalent: Preparation and Palladium-Catalyzed Coupling with Aryl Halides. J. Org. Chem. 1991, 56, 7336-7340. f) J. -P. Bégué, D. Bonnet-Delpon, D. R. Dogbeavou, M. Ourévitch, Trifluoromethylated Furans via Iodocyclisation ofγ-Unsaturated Ethyl Trifluoroa
cetoacetates. J. Chem. Soc. Perkin Trans 1, 1993, 2787-2791.
[26]李汝霖.有机氟工业[J]. 1992, 2, 14-19.
[27] W. Zhuang, N. Gathergood, R. G. Hazell, K A. J?rgensen. Catalytic, Highly Enantioselective Friedel?Crafts Reactions of Aromatic and Heteroaromatic Compounds to Trifluoropyruvate. A Simple Approach for the Formation of Optically Active Aromatic and Heteroaromatic Hydroxy Trifluoromethyl Esters. J. Org. Chem. 2001, 66, 1009.
[28] P. A. Lyle. Michael, N. Draper. Draper, D.Wilson. Peter. EnantioselectiveFriedel?Crafts Alkylation Reactions Catalyzed by a Chiral Nonracemic C- Symmetric 2, 2'- Bipyridyl Copper(II) Complex. Org. Lett ,2005, 7, 901.
[29] K. Mikami, K. Aikawa, S. Kainuma, et al, Enantioselective Catalysis of Carbonyl-Ene and Friedel-Crafts reactions with Trifluoropyruvate by‘naked’Palladium(II) Complexes with SEGPHOS Ligands. Tetrahedron: Asymmetry 2004, 15, 3885-3889.
[30] K. Mikami, H. Kakuno, K. Aikawa, Enantiodiscrimination and Enantiocontrol of Neutral and Cationic PtII Complexes Bearing the Tropos Biphep Ligand: Applicaltion to Asymmetric Lewis Acid Catalytic. Angew. Chem. Int. Ed. 2005, 44, 7257-7260.
[31] B. T?r?k, M. Abid, G. London, J. Esquibel, M. T?r?k, Shilpa C. Mhadgut, P. Yan, G. K. Surya Prakash. Highly Enantioselective Organocatalytic Hydroxyalkylation of Indoles with Ethyl Trifluoropyruvate. Angew. Chem. Int.Ed. 2005, 44,3086.
[32] S. Ogawa, N. Shibata, J. Inagaki, S. Nakamua, T. Toru, M. Shiro, Cinchona- Alkaloid-Catalyzed Enantioselective Direct Aldol-Type Reaction of Oxindoles with Ethyl Trifluoropyruvate. Angew. Chem. Int. Ed. 2007, 46, 8666-8669.
[33] R. Sting Andrea, Seebach Dieter. Synthesis of (2R,3S)- or (2S,3R)-2-Amino-3- Trifluoromethyl-3-hydroxy-alkanoic Acid Derivative(Threonine and allo- Threonine Analogs) from Enantiopure 4,4,4-trifluoro-3-hydroxybutanoic Acid. Tetrahedron. 1996, 52: 279.
[34] a) M. V. Arx, T. Mallat, A. Baiker. First Enantioselective Hydrogenation of a Trifluoro-ketoester with Cinchona-Modified Platinum. J. Catal. 2000, 193, 161. b) M. V. Arx, T. Mallat, A.Baiker. Tetrahedron: Asymmetry. 2001, 12, 3089.
[35] J. Nie, G.. -W. Zhang, L. Wang, A. p. Fu, J. -A. Ma. Chiral Br?nsted Acid-Catalyzed Enantioselectiv Arylation of Ethyl Trifluoro-acetoacetate and Ethyl Trifluoropyruvate. Submitted to Org. Biomol. Chem. ASAP
[36] a) K. Mikami, T. Yajima, M. Terada, E. Kato, M, Maruta, Diastereoselective and Enantioselective Catalysis of the Carbonyl-Ene Reaction with Fluoral. Tetrahedron: Asymmetry 1994, 5, 1087-1090. b) K. Mikami, T. Yajima, T. Takasaki, S. Matsukawa, M. Terada, T. Uchimaru, M. Maruta, Asymmetric Catalysis of Carbonyl-Ene and Aldol Reactions with Fluoral by Chiral Binaphthol-Derived Titanium Complex. Tetrahedron 1996, 52, 85-98.
[37] A. Ishii, J. Kojima, K. Mikami, Asymmetric Catalytic Friedel-Crafts Reaction ofSilyl Enol Ethers with Fluoral: A Possible Mechanism of the Mukaiyama-Aldol Reactions. Org. Lett. 1999, 1, 2013-2016.
[38] A. Ishii, V. A. Soloshonok, K. Mikami, Asymmetric Catalysis of the Friedel- Crafts Reaction with Fluoral by Chiral Binaphthol-Derived Titanium Catalysts through Asymmetric Activation. J. Org. Chem. 2000, 65, 1597-1599.
[39] G. -W. Zhang, L. Wang, J. Nie, J.–A. Ma. Chiral Br?nsted Acid-Mediated Enantioselective Organocatalytic Three Component Reaction for the Construction of Trifuoromethyl-Containing Molecules. Adv. Synth. Catal. 2008, 350, 1457-1463.
[40] E. J. Corey, X.-M. Cheng, K. A. Climprich, S. Sarshar, Remarkably Effective and Simple Synthesis of Enantiomerically Pure Secondary Carbinols from Achiral Ketones. Tetrahedron Lett. 1991, 32, 6835-6838.
[41] M. Bandini, R. Sinisi, A. Umani-Ronchi, Enantioselective Organocatalyzed Henry Reaction with Fluoromethyl Ketones. Chem. Commun. 2008, 4360-4362.
[42] X.-J. Wang, Y. Zhao, J.-T. Liu, Regiospecific Organocatalytic Asymmetric Aldol Reaction of Methyl Ketones andα,β-Unsaturated Trifluoromethyl Ketones. Org. Lett. 2007, 9, 1343.
[43] J Nie, G..W. Zhang, L. Wang, A. p. Fu, J. -A. Ma. A Perfect Double Role of CF3 groups in Activating Substrates and Stabilizing Adducts: the Chiral Br?nsted Acid-Catalyzed Direct Arylation of Trifluoromethyl Ketones. Chem. Commun. 2009, ASAP.
[44] S. Mizuta, N. Shibata, Y. Goto, T. Furukawa, S. Nakamura, T. Toru, Cinchona Alkaloid-Catalyzed Enantioselective Monofluoromethylation Reaction Based on Fluorobis(phenylsulfonyl)methane Chemistry Combined with a Mannich-type Reaction. J. Am. Chem. Soc. 2007, 129, 6394-6395.
[45] I. L. Baraznenok, V. G. Nenajdenko, and E. S. Balenkova. 3-Trifloxy-3- trifluoromethylpropeniminium Triflate: Reaction with Aromatic Amines-An Efficient Synthesis of 2-Trifluoromethylquinolines. Eur. J. Org. Chem. 1999, 937-941.
[46] R. J. Andrew, J. M. Mellor. Synthesis ofα,β-Unsaturated Trifluoromethyl Ketones from 4-Dimethylamino-1,1,1-trifluorobut-3-ene-2-one by Addition of Grignard Reagents. Tetrahedron. 2000, 56, 7261-7266.
[2] C. Friedel, J. M. Crafts. Bull. Soc. Chim. Fr. 1877, 27, 530.
[3] For reviews: a)王以,丁奎岭.催化不对称Friedel-Crafts反应.有机化学, 2001, 21, 763. b) Y. Wang, K. L. Ding. Chemtracts. 2001, 14, 610.c) M. Bandini, A. Melloni, Umani-Ronchi. New Catalytic Approaches in the Stereoselective Friedel–Crafts Alkylation Reaction. Angew. Chem. Int. Ed. 2004, 43, 550.
[4] J. F. Austin, D. W. C. MacMillan. Enantioselective Organocatalytic Indole Alkylatio Design of a New and Highly Effective Chiral Amine for Iminium Catalysis. J. Am. Chem. Soc. 2002, 124, 1172.
[5] K. B. Jensen, J. Thorhauge, R. G. Hazell, K. A. J?rgensen. Catalytic Asymmetric Friedel– Crafts Alkylation ofα,β-Unsaturated a-Ketoesters: Enantioselective Addition of Aromatic C-H Bonds to Alkenes. Angew. Chem. Int. Ed. 2001, 40, 160.
[6] J. Zhou, Y. Tang. Sidearm Effect: Improvement of the Enantiomeric Excess in the Asymmetric Michael Addition of Indoles to Alkylidene Malonates. J. Am. Chem. Soc. 2002, 124, 9030-9031.
[7] G. Desimoni, G. Faita, M. Toscanini, M Boiocchi. Asymmetric Friedel–Crafts Alkylation of Indoles with Methyl (E)-2-Oxo-4-aryl-3-butenoates Catalyzed by Sc(OTf)3/pybox. Chem. Eur. J. 2008, 14, 3630–3636.
[8] M. Bandini, M. Fagioli, P. Melchiorre, A. Melloni, A. Umani-Ronchi. Catalytic enantioselective conjugate addition of indoles to simpleα,β-Unsaturated ketones. Tetrahedron Letters. 2003, 44, 5843–5846.
[9] For books and reviews: a) A. Berkessel, H. Groger. Asymmetric Organocatalysis, Wiley-VCH, Meinheim, 2004. b) P. I. Dalko, L. Moisan. In the Golden Age of Organocatalysis. Angew. Chem. Int. Ed.2004, 43, 5138.c) J. Seayad,; B.List. Asymmetric organocatalysis.Org. Biomol. Chem. 2005, 3, 719.d) H. Pellissier. Tetrahedron. Asymmetric organocatalysis. 2007, 63, 9267.e) P. I. Dalko.Enantioselective Organocatalysis, Wiley-VCH. Weinheim,2007.
[10] J. F. Austin, D. W. C. MacMillan. Enantioselective Organocatalytic Indole Alkylatio Design of a New and Highly Effective Chiral Amine for Iminium Catalysis. J. Am. Chem. Soc. 2002, 124, 1172.
[11] C.-F. Li, Y.-J. Cao, X.-P. Liu,W.-J. Xiao. Enantioselective Organocatalytic Intramolecular Ring-Closing Friedel-Crafts-Type Alkylation of Indoles. Org. Lett. 2007, 9, 1847.
[12] N. A. Paras, D. W. C. MacMilan. The Enantioselective Organocatalytic 1,4- Addition of Electron-Rich Benzenes toα,β-Unsaturated Aldehydes. J. Am. Chem. Soc. 2002, 124, 7894.
[13] W.Zhou, L.-W. Xu , L. Li, L.Yang, C.-G. Xia. Enantioselective Michael-Type Friedel–Crafts Reactions of Indoles to Enones Catalyzed by a Chiral Camphor- Based Br?nsted Acid. Eur.J.Org.Chem.2006,71,5225.
[14] W. Chen, W. Du, L.Yue, R. Li, Y. Wu, L.-S. Ding, Y,-C. Chen. Organocatalytic enantioselective indole alkylations ofα,β-unsaturated ketones. Org.. Biomol. Chem. 2007, 5, 816.
[15] Giuseppe Bartoli, Marcella Bosco, Armando carlone, Fabio Pesciaioli, Letizia Sambri,and Paolo Melchiorre, Organocatalytic Asymmetric Friedel-Crafts . Org. Lett. 2007, 9, 1403.
[16] H.-Y. Tang, A.-D. Lu, Z.-H. Zhou, G.-F.Zhao, L.-N. He, C.-C. Tang. Chiral Phosphoric Acid Catalyzed Asymmetric Friedel–Crafts Alkylation of Indoles with Simpleα,β-Unsaturated Aromatic Ketones. Eur. J. Org. Chem. 2008, 1406–1410.
[17] W. Zhuang, T. B. Poulsen, K.A. J?rgensen. A versatile catalyst for asymmetric reactions of carbonyl groups working purely by activation through hydrogen bonding: Mukaiyama-aldol, hetero Diels–Alder and Friedel–Crafts reactions.Org. Biomol. Chem. 2005, 3, 3284.
[18] H.-M.Li, Y.-Q. Wang, L. Deng. Enantioselective Friedel?Crafts Reaction of Indoles with Carbonyl Compounds Catalyzed by Bifunctional Cinchona Alkaloids.Org. Lett. 2006, 8, 4063.
[19] W. Zhuang, R. G. Hazell, K.A. J?rgensen. Enantioselective Friedel–Crafts type addition of indoles to nitro-olefins using a chiral hydrogen-bonding catalyst– synthesis of optically active tetrahydro-β-carbolines. Org. Biomol. Chem., 2005, 3, 2566– 2571.
[20] R. P. Herrera, V. Sgarzani, L. Bemardi, A. Ricci. Catalytic Enantioselective Friedel-Crafts Alkylation of Indoles with Nitroalkenes by Using a Simple Thiourea Organocatalyst. Angew. Chem. Int. Ed. 2005, 44, 6576.
[21] E. M. Flemimg, T. McCabe,S. J. Connon. Novel axially chiral bis-arylthiourea-based organocatalysts for asymmetric Friedel-Crafts type reactions. Tetrahedron Lett. 2006, 47, 7037.
[22] K. Johns, G.. Stead. Fluoroproducts-the extremophiles. J. Fluorine. Chem. 2000, 104, 5-18.
[23] a) F. M. D. Ismail, Important fluorinated drugs in experimental and clinical use. J. Fluorine. Chem. 2002, 118, 27-33. b) C. Isanbor, D. O’Hagan, Fluorine in Medical Chemistry: A Review of anti-cancer Agents. J. Fluorine. Chem. 2006, 127, 303-319.
[24]卿凤翎,邱小龙,有机氟化学,北京:科学出版社, 2007, p135.
[25] a) F. Camps, J. Coll, G. Fabrias, A. Guerrero, Synthesis of Dienic Fluorinated Analogs of Insect Sex Pheromones. Tetrahedron 1984, 40, 2871-2878. b) E. A. Hallinan, J. Fried, 2,2-Difluoro-3-Hydroxyesters by Reformatsky Reaction. Tetrahedron 1984, 25, 2301-2302. c) D. Seyfeth, R. M. Simon, D. J. Sepelak, H. A. Klein, gem-(Difluoroallyl)lithium: Preparation by Lithium-Halogen Exchange and Utilization in Organosillicon and Organic Synthesis. J. Am. Chem. Soc. 1983, 105, 4634-4639. d) F. Tian, V. Kruger, W. R. Dolhier, Q. Y. Chen, et al, A Novel and Highly Efficient Synthesis of gem-Difluorocyclopropanes. Org. Lett. 2000, 2, 563-564. e) B. Jiang, Y.–Y. Xu, Trifluoroisopropenylzinc Reagent as A Usefulα-(Trifluoromethyl)ethenyl Carbanion Synthetic Equivalent: Preparation and Palladium-Catalyzed Coupling with Aryl Halides. J. Org. Chem. 1991, 56, 7336-7340. f) J. -P. Bégué, D. Bonnet-Delpon, D. R. Dogbeavou, M. Ourévitch, Trifluoromethylated Furans via Iodocyclisation ofγ-Unsaturated Ethyl Trifluoroa
cetoacetates. J. Chem. Soc. Perkin Trans 1, 1993, 2787-2791.
[26]李汝霖.有机氟工业[J]. 1992, 2, 14-19.
[27] W. Zhuang, N. Gathergood, R. G. Hazell, K A. J?rgensen. Catalytic, Highly Enantioselective Friedel?Crafts Reactions of Aromatic and Heteroaromatic Compounds to Trifluoropyruvate. A Simple Approach for the Formation of Optically Active Aromatic and Heteroaromatic Hydroxy Trifluoromethyl Esters. J. Org. Chem. 2001, 66, 1009.
[28] P. A. Lyle. Michael, N. Draper. Draper, D.Wilson. Peter. EnantioselectiveFriedel?Crafts Alkylation Reactions Catalyzed by a Chiral Nonracemic C- Symmetric 2, 2'- Bipyridyl Copper(II) Complex. Org. Lett ,2005, 7, 901.
[29] K. Mikami, K. Aikawa, S. Kainuma, et al, Enantioselective Catalysis of Carbonyl-Ene and Friedel-Crafts reactions with Trifluoropyruvate by‘naked’Palladium(II) Complexes with SEGPHOS Ligands. Tetrahedron: Asymmetry 2004, 15, 3885-3889.
[30] K. Mikami, H. Kakuno, K. Aikawa, Enantiodiscrimination and Enantiocontrol of Neutral and Cationic PtII Complexes Bearing the Tropos Biphep Ligand: Applicaltion to Asymmetric Lewis Acid Catalytic. Angew. Chem. Int. Ed. 2005, 44, 7257-7260.
[31] B. T?r?k, M. Abid, G. London, J. Esquibel, M. T?r?k, Shilpa C. Mhadgut, P. Yan, G. K. Surya Prakash. Highly Enantioselective Organocatalytic Hydroxyalkylation of Indoles with Ethyl Trifluoropyruvate. Angew. Chem. Int.Ed. 2005, 44,3086.
[32] S. Ogawa, N. Shibata, J. Inagaki, S. Nakamua, T. Toru, M. Shiro, Cinchona- Alkaloid-Catalyzed Enantioselective Direct Aldol-Type Reaction of Oxindoles with Ethyl Trifluoropyruvate. Angew. Chem. Int. Ed. 2007, 46, 8666-8669.
[33] R. Sting Andrea, Seebach Dieter. Synthesis of (2R,3S)- or (2S,3R)-2-Amino-3- Trifluoromethyl-3-hydroxy-alkanoic Acid Derivative(Threonine and allo- Threonine Analogs) from Enantiopure 4,4,4-trifluoro-3-hydroxybutanoic Acid. Tetrahedron. 1996, 52: 279.
[34] a) M. V. Arx, T. Mallat, A. Baiker. First Enantioselective Hydrogenation of a Trifluoro-ketoester with Cinchona-Modified Platinum. J. Catal. 2000, 193, 161. b) M. V. Arx, T. Mallat, A.Baiker. Tetrahedron: Asymmetry. 2001, 12, 3089.
[35] J. Nie, G.. -W. Zhang, L. Wang, A. p. Fu, J. -A. Ma. Chiral Br?nsted Acid-Catalyzed Enantioselectiv Arylation of Ethyl Trifluoro-acetoacetate and Ethyl Trifluoropyruvate. Submitted to Org. Biomol. Chem. ASAP
[36] a) K. Mikami, T. Yajima, M. Terada, E. Kato, M, Maruta, Diastereoselective and Enantioselective Catalysis of the Carbonyl-Ene Reaction with Fluoral. Tetrahedron: Asymmetry 1994, 5, 1087-1090. b) K. Mikami, T. Yajima, T. Takasaki, S. Matsukawa, M. Terada, T. Uchimaru, M. Maruta, Asymmetric Catalysis of Carbonyl-Ene and Aldol Reactions with Fluoral by Chiral Binaphthol-Derived Titanium Complex. Tetrahedron 1996, 52, 85-98.
[37] A. Ishii, J. Kojima, K. Mikami, Asymmetric Catalytic Friedel-Crafts Reaction ofSilyl Enol Ethers with Fluoral: A Possible Mechanism of the Mukaiyama-Aldol Reactions. Org. Lett. 1999, 1, 2013-2016.
[38] A. Ishii, V. A. Soloshonok, K. Mikami, Asymmetric Catalysis of the Friedel- Crafts Reaction with Fluoral by Chiral Binaphthol-Derived Titanium Catalysts through Asymmetric Activation. J. Org. Chem. 2000, 65, 1597-1599.
[39] G. -W. Zhang, L. Wang, J. Nie, J.–A. Ma. Chiral Br?nsted Acid-Mediated Enantioselective Organocatalytic Three Component Reaction for the Construction of Trifuoromethyl-Containing Molecules. Adv. Synth. Catal. 2008, 350, 1457-1463.
[40] E. J. Corey, X.-M. Cheng, K. A. Climprich, S. Sarshar, Remarkably Effective and Simple Synthesis of Enantiomerically Pure Secondary Carbinols from Achiral Ketones. Tetrahedron Lett. 1991, 32, 6835-6838.
[41] M. Bandini, R. Sinisi, A. Umani-Ronchi, Enantioselective Organocatalyzed Henry Reaction with Fluoromethyl Ketones. Chem. Commun. 2008, 4360-4362.
[42] X.-J. Wang, Y. Zhao, J.-T. Liu, Regiospecific Organocatalytic Asymmetric Aldol Reaction of Methyl Ketones andα,β-Unsaturated Trifluoromethyl Ketones. Org. Lett. 2007, 9, 1343.
[43] J Nie, G..W. Zhang, L. Wang, A. p. Fu, J. -A. Ma. A Perfect Double Role of CF3 groups in Activating Substrates and Stabilizing Adducts: the Chiral Br?nsted Acid-Catalyzed Direct Arylation of Trifluoromethyl Ketones. Chem. Commun. 2009, ASAP.
[44] S. Mizuta, N. Shibata, Y. Goto, T. Furukawa, S. Nakamura, T. Toru, Cinchona Alkaloid-Catalyzed Enantioselective Monofluoromethylation Reaction Based on Fluorobis(phenylsulfonyl)methane Chemistry Combined with a Mannich-type Reaction. J. Am. Chem. Soc. 2007, 129, 6394-6395.
[45] I. L. Baraznenok, V. G. Nenajdenko, and E. S. Balenkova. 3-Trifloxy-3- trifluoromethylpropeniminium Triflate: Reaction with Aromatic Amines-An Efficient Synthesis of 2-Trifluoromethylquinolines. Eur. J. Org. Chem. 1999, 937-941.
[46] R. J. Andrew, J. M. Mellor. Synthesis ofα,β-Unsaturated Trifluoromethyl Ketones from 4-Dimethylamino-1,1,1-trifluorobut-3-ene-2-one by Addition of Grignard Reagents. Tetrahedron. 2000, 56, 7261-7266.