瓜环与多作用位点的链状有机分子的相互作用研究
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摘要
瓜环是一类具有疏水性空腔，且在其端口周围环绕着羰基氧的新型主体化合物，随着其不同尺寸的空腔及端口口径的同系物的发现，瓜环已成为超分子化学主客体化学中的一个重要研究领域，特别是在主客体化学、分子识别、分子自组装等方面的应用而受到国内外相关学科研究者的密切关注。
本文基于前人和我们实验室现有的研究基础，设计合成了一系列长短不一具有多作用位点的链状有机客体分子：六个二吡啶基烷烃二溴化物以及八个N，N’-双烷基-4，4，-联吡啶二溴化物或盐酸盐，利用~1H NMR技术、单晶X-衍射技术、紫外吸收光谱和电化学方法考察了这些客体与六、七、八元瓜环以及对称四甲基六元瓜(TMeQ[6])的相互作用，以及形成的主客体包结配合物的结构特征。研究结果表明：
1．六个二吡啶基烷烃二溴化物客体均能与六、七、八元瓜环形成主客体配合物，但作用模式随碳链的长度、瓜环的大小而各不相同。
2．TMeQ[6]与二吡啶基丁烷二溴化物(Bdpy)相互作用形成的主客体配合物在固体状态下和在水溶液中作用模式却各不相同。在固体状态下是仅Bdpy分子的一个的吡啶环进入TMeQ[6]的空腔内，另一个吡啶环处在TMeQ[6]的空腔外部，形成不对称的主客体包结配合物；在水溶液中则是一个Bdpy分子的两个吡啶环都分别进入两个主体TMeQ[6]空腔中的一部分形成哑铃型的包结配合物。
3．主体Q[8]与这八个客体相互作用模式随着碳链长短不一而各不相同。一种情况下，Q[8]与碳链长度低于或等于4的客体形成1：1的包结配合物，但Q[8]与4，4-联吡啶盐酸盐(Bpy~(2+))在酸性条件下却形成1：2的包结配合物；而另一种情况下，主体Q[8]与一个碳链长度大于4的客体分子形成2：1甚至3：1的包结配合物。
A hydrophobic cavity, and polar carbonyl groups surrounding the opening portals are common characteristic features for a new receptor family—Cucurbit[n]urils (Q[n]s). The varying cavity and portal sizes, particularly, the ability to form inclusion or exclusion complexes with organic species or inorganic ions lead to Q[n]s remarkable molecular recognition properties and the building block for supramolecular chemistry that promoted quite a few researchers to focus on this area.
In this work, six 1,(?)-alkylenedipyridinium dibromide guests and a series of viologen derivates were synthesized , while structures and interaction of cucurbit[6,7,8]urils with the guests were investigated by ~1H NMR techniques, UV-Vis spectroscopy, X-ray diffraction analysis and conductivity in details.
1. The host-guest complexes were formed between six 1,? -alkylenedipyridinium dibromide guests and cucurbit[6,7,8]urils, while the interaction types were different for the six guests and cucurbit[6]uril, cucurbit[7]uril or cucurbit[8]uril respectively.
2. The interaction between a symmetrical substituted cucurbit[6]uril (TMeQ[6]) and the guest of dibromine salt of 1,4-butyldipyridine (Bdpy) was studied. The X-ray crystallographic determination reveals that each TMeQ[6] host includes only one of pyridine ring of a Bdpy guest, the rest part of the Bdpy guest is located at one portal of the TMeQ[6] to form a unsymmetrical host-guest inclusion complex. Contrary to expectations, the ~1H NMR results show that both of pyridine rings of the Bdpy guest seem to be included in the cavity of the TMeQ[6] host.
3. The binding site on the guests depended strongly on the length of the aliphatic substituents on the bipyridinium nucleus: a 1:1 complex was formed for Q[8]-viologen derivates with chains shorter that four carbon atoms, while a 1:2 complex for Q[8]-BPY~(2+) was observed under acidic condition. However, two or three Q[8] molecules could be threaded on a viologen derivates with chains longer that four carbon atoms molecule to form a 2:1, even 3:1 complex respectively.
本文基于前人和我们实验室现有的研究基础，设计合成了一系列长短不一具有多作用位点的链状有机客体分子：六个二吡啶基烷烃二溴化物以及八个N，N’-双烷基-4，4，-联吡啶二溴化物或盐酸盐，利用~1H NMR技术、单晶X-衍射技术、紫外吸收光谱和电化学方法考察了这些客体与六、七、八元瓜环以及对称四甲基六元瓜(TMeQ[6])的相互作用，以及形成的主客体包结配合物的结构特征。研究结果表明：
1．六个二吡啶基烷烃二溴化物客体均能与六、七、八元瓜环形成主客体配合物，但作用模式随碳链的长度、瓜环的大小而各不相同。
2．TMeQ[6]与二吡啶基丁烷二溴化物(Bdpy)相互作用形成的主客体配合物在固体状态下和在水溶液中作用模式却各不相同。在固体状态下是仅Bdpy分子的一个的吡啶环进入TMeQ[6]的空腔内，另一个吡啶环处在TMeQ[6]的空腔外部，形成不对称的主客体包结配合物；在水溶液中则是一个Bdpy分子的两个吡啶环都分别进入两个主体TMeQ[6]空腔中的一部分形成哑铃型的包结配合物。
3．主体Q[8]与这八个客体相互作用模式随着碳链长短不一而各不相同。一种情况下，Q[8]与碳链长度低于或等于4的客体形成1：1的包结配合物，但Q[8]与4，4-联吡啶盐酸盐(Bpy~(2+))在酸性条件下却形成1：2的包结配合物；而另一种情况下，主体Q[8]与一个碳链长度大于4的客体分子形成2：1甚至3：1的包结配合物。
A hydrophobic cavity, and polar carbonyl groups surrounding the opening portals are common characteristic features for a new receptor family—Cucurbit[n]urils (Q[n]s). The varying cavity and portal sizes, particularly, the ability to form inclusion or exclusion complexes with organic species or inorganic ions lead to Q[n]s remarkable molecular recognition properties and the building block for supramolecular chemistry that promoted quite a few researchers to focus on this area.
In this work, six 1,(?)-alkylenedipyridinium dibromide guests and a series of viologen derivates were synthesized , while structures and interaction of cucurbit[6,7,8]urils with the guests were investigated by ~1H NMR techniques, UV-Vis spectroscopy, X-ray diffraction analysis and conductivity in details.
1. The host-guest complexes were formed between six 1,? -alkylenedipyridinium dibromide guests and cucurbit[6,7,8]urils, while the interaction types were different for the six guests and cucurbit[6]uril, cucurbit[7]uril or cucurbit[8]uril respectively.
2. The interaction between a symmetrical substituted cucurbit[6]uril (TMeQ[6]) and the guest of dibromine salt of 1,4-butyldipyridine (Bdpy) was studied. The X-ray crystallographic determination reveals that each TMeQ[6] host includes only one of pyridine ring of a Bdpy guest, the rest part of the Bdpy guest is located at one portal of the TMeQ[6] to form a unsymmetrical host-guest inclusion complex. Contrary to expectations, the ~1H NMR results show that both of pyridine rings of the Bdpy guest seem to be included in the cavity of the TMeQ[6] host.
3. The binding site on the guests depended strongly on the length of the aliphatic substituents on the bipyridinium nucleus: a 1:1 complex was formed for Q[8]-viologen derivates with chains shorter that four carbon atoms, while a 1:2 complex for Q[8]-BPY~(2+) was observed under acidic condition. However, two or three Q[8] molecules could be threaded on a viologen derivates with chains longer that four carbon atoms molecule to form a 2:1, even 3:1 complex respectively.
引文
1 Lehn J. M., Perspectives in Coordination Chemistry (eds.WiUiams A F, Floriani C,Merbach A S) VCH,New York, 1992, 447.
2 Motohiro Nishio; Yoji Umezawa; Minoru Hirota; Yasuo Takeuchi. The CH/π Interaction: Significance in molecular recognition. Tetrahedron, 1995, 51, 8665.
3 Hiroki Takahashi; Sei Tsuboyama; Yoji Umezawa; Kazumasa Honda; Motohiro Nishio; CH/π interactions as demonstrated in the crystal structure of host/guest compounds. A database study.Tetrahedron, 2000, 56, 6185.
4 Gillard, Richard E.; Raymo, Francisco M.; Stoddart, J. Fraser Molecular meccano.26.controlling self-assembly. Chem.-Eur.J. ,1997, 3(12), 1933.
5 Mock W. L, Shih N. Y., Dynamics of molecular recognition involving cncurbituril. J. Am. Chem. Soc., 1989, 111(7), 2697.
6 Mock W. L., Irra T A, Wepsiec James P, et al. Catalysis by cucurbituril. The significance of bound-substrate destabilization for induced triazole formation. J. Org. Chem., 1989, 54(22), 5302.
7 (a) Gutsche, C. D. In Calixarnes, Monogophs in Supramolecular Chemistry, Ed.: Stoddsrt, J. E, Royal Society of Chemistry, London,1989,p.1. (b) Vicens, J.; B6hmer, V. Calixarenes. A Versatile Class of Macrocyclc Compounds, Kluwer Academic Publishers, Dordrecht,The Netherlands, 1991, p. 1. (c) McKervey, M. A.; Schwing-Weill, M.-J.; Amaud-Neu, EIn Comprehensive Supramolecular Chemistry, Vol. 1, Eds.:Atwood, J. L; Davies, J. E. D.; MacNicol, D. D.; Vǒgtle,E, Pergamon Press, Oxford, 1996, p. 537. (d) Bǒhmer, V.Angew. Chem.,Int. Ed. Engl. 1995, 34 (7), 713. (e) Danil de NaMOR,, A. E;Cleverley, R. M.; Zapata-Ormachea, M. L. Chem. Rev. 1998, 98(7), 2495.
8 Behrend, R.; Meyer, E.; Rusche, E Liebigs Ann.Chem. 1905,339, 1
9 W.A. Freeman, W. L. Mock, and N. Y. shih Cucurbituril J. Am. Chem. Soc. 1981, 103, 7367-7368
10 Kim J, Jung I S, Kim S Y, et al. New Cucurbituril Homologues: Syntheses, Isolation, Characterization, and X-ray Crystal Structures of Cucurbit[n]uril (n=5, 7, and 8). J.Am. Chem. Soc., 2000,122(3): 540-541
11 Buschmann, H.-J.; Cleve, E.; Jansen, K.; Wego, A.; SchoUeyer, E. J. Incusion Phenom. Md.??Recognit. Chem. 2001, 40, 117
12 Bushmann, H.-J.;Cleve, E.; Jansen, K.;Schoileyer, E. Anal. Chim. Acta 2001, 437, 157
13 Mock, W. L.; Shih, N.-Y. J. Org. Chem. 1983,48 (20), 3617.
14 Mock, W. L.; Shih, N.-Y. J. Org. Chem. 1986, 51 (20), 4440.
15 Mock, W. L.; Shih, N.-Y. J. Org. Chem. Soc. 1998, 110 (14), 4706.
16 Neugebauer R, Knoche W. J. Chem. Soc., Perkin Trans. 2, 1998, (3), 529.
17 WinstonO, MarielleGK, AngelE, etal. new--Cucurbit[7]uril: A Very Effective Host for Viologens andTheir Cation Radicals. Organic Letters, 2002, 4(10): 1791-1794
18 Bushmann, H.-j.; Schollmeyer, E. J. Inclusion Phenom. Mol. Recognit. Chem. 1992,14,91.
19 黎占亭，轮烷研究-从超分子组装到分子机器Chinese Journal 0fOrganic．Chemistry,2000， 20(5)，655．
20 G Schill. Catenanes,Rotaxanes,and Knots,Academic Press, New York, 1971
21 J G Chambron,G O Dietrich-Buchecker, V Heitz, J F Nierengarten,J P Sauvage, G Pascard,J Guilhem. Pure Appl.Chem.,1995,67,233
22 J P Sauvage.Acc. Chem.Res.,1998,31,611
23 D B Amabilino, J F Stoddart. Chem.Rev.1995,95,2725
24 V Balzani,M Gomez-Lopez, J F Stoddart.Acc. Chem.Res.1998,31,405
25 F V6gtle, T Dunnwald, T Schmidt.Acc.Chem.Res.,1996,29,451
26 H W Gibson,M G Bheda,P T Engen. Prog.Polym.Sci., 1994,19,843
27 G J Glarkson,D A Leigh, R A Smith.Curr.Op.Solid State and Mat.Sci.,1998,3,570
28 J Becher, Z TLi, N Svenstrup.J Jau,M B Nielsen,P Leriche.Pure.Appl.Chem., 1997,69,465
29 li, P G Stein,J Becher, D Jensen,N Svenstrp.Chem.Eur.J.,1996,2,624
30 (a)Mock, W. L. In Comprehensive Supramolecular Chemistry, Vol.2,Eds.:Atwood,J.L.;Davies,J.E.D.;MacNicol,D.D.;V6gtle,F.,Pergamon Press, Oxford, 1996, p.477. (b) Mock, W. L. Top. Curt. Chem. 1995, 175, 1. (c) Cintas, P. J. Incusion Phenom. Mol. Recognit.Chem.1994, 17, 205.
31 Jeon, Y.-M.; Whang, D.; Kim, J.; Kirn, K. Chem.Lett.1996, 503.
32 Buschmann, H.-J.; Wego, A.; Schollmeyer, E.; D6pp, D.Supramol. Chem. 2000, 11,225.33 Meschke, C.; Buschmann, H.-J.; Schollmeyer, E. Macromol.Rapid Gommun. 1998, 19, 59.
34 Sokolov, M. N.; Virovets, A. V.; Dybtsev, D. N.; Gerasko,O. A.; Fedin, V.P.;Hernandez-Molina, R.; Clegg, W.;Sykes, A. G. Angew.Chem., Int. Ed. 2000, 39, 1659.
35 Whang, D.; Jeon, Y.-M.; Heo, J.; Kim, K. J. Am. Chem. Soc. 1996, I18(45), 11333.
36 Whang, D.; Kim, K. Polycatenated Two-Dimensional Polyrotaxane Net. J. Am. Chem; Soc. 1997, 119451.
37 Whang, D.; Park, K.-M.; Heo, J.; Ashton, P.; Kim, K. J. Am. Chem. Soc. 1996, 120(19), 4899.
38 Whang, D.;Heo, J.;Kim, C.-A.;Kim, K. Chem. Commun. 1997, 2361.
39 lee, E.; Kim, J.; Heo, J.; Whang, D.; Kirn, K. Angew.Chem., Int. Ed. 2001, 40(2), 399.
40 Theodora, W. G. Productive Groups In Organic Synthesis, John Wiley & Sons Ltd., Harvard University, 1981, p. 316.
41 Meschke, C.; Buschrnann, H. J.; Schollmeyer, E. Polymer 1999, 40, 945.
42 Xu, Z. Q.; Yao, X. Q.; Xue, S. F.; Zhu, Q. J.; Tao, Z.; Zhang, J. X.; Wei, Z. B. ; Long, L. S. Acta Chim. Sinica 2004, 62, 1927 (in Chinese). (徐周庆，姚晓青，薛赛凤，祝黔江，陶朱，张建新，魏赞斌，龙腊生，化学学报，2004，62，1927)
43 Yong, G. P. ; Li, G. S. ; Yan, X. Y. ; Liu. S. M. Fine Chemical 2003, 20(1), (in Chinese). (雍国平，李光水，阎向阳，刘少民，精细化工，2003，20(1)，16)
44 Yang, S. L.; Xue, S. F.; Ma, P. H.; Zhu, Q. J.; Tao, Z.; Zhang, J. X. Chin. J. Org. Chem. 2005, 25, 1215. (杨守林，薛赛凤，马培华，祝黔江，陶朱，张建新，有机化学，2005，25，1215．
45 Xiang, S. Chuna. : Tao, Z. ; HuY. : XiangZ. M. ; Xue, S. F.; Zhu, Q. J.; Zhang, J. X. Chin. J. Org. Chem. 2005, 25, 1208. (向双春，陶朱，胡育，向章敏，薛赛凤，祝黔江，张建新，有机化学，2005，25，1208．)
46 Fu H. Y.; Xue, S. F.; Zhu, Q. J.; Tao, Z.; Zhang, J. X.; Day, A. I. Inc. Phenom. Macro. Chem. 2005, 52(1), 101.
47 (a) Sindelar, V.; Cejas, M.A.; Raymo, EM.; Kaifer, A. E. New J. Chem. 2005, 29, 280. (b) Sindelar, V.; Moon, K.; Kaifer, A. E. Org. Lett. 2004, 6, 2665. (c) Ong, W.; Kaifer, A. E. J. Org. Chem. 2004, 69, 1383. (d) Moon, K.; Kaifer, A. E. Org. Lett. 2004, 6, 185
2 Motohiro Nishio; Yoji Umezawa; Minoru Hirota; Yasuo Takeuchi. The CH/π Interaction: Significance in molecular recognition. Tetrahedron, 1995, 51, 8665.
3 Hiroki Takahashi; Sei Tsuboyama; Yoji Umezawa; Kazumasa Honda; Motohiro Nishio; CH/π interactions as demonstrated in the crystal structure of host/guest compounds. A database study.Tetrahedron, 2000, 56, 6185.
4 Gillard, Richard E.; Raymo, Francisco M.; Stoddart, J. Fraser Molecular meccano.26.controlling self-assembly. Chem.-Eur.J. ,1997, 3(12), 1933.
5 Mock W. L, Shih N. Y., Dynamics of molecular recognition involving cncurbituril. J. Am. Chem. Soc., 1989, 111(7), 2697.
6 Mock W. L., Irra T A, Wepsiec James P, et al. Catalysis by cucurbituril. The significance of bound-substrate destabilization for induced triazole formation. J. Org. Chem., 1989, 54(22), 5302.
7 (a) Gutsche, C. D. In Calixarnes, Monogophs in Supramolecular Chemistry, Ed.: Stoddsrt, J. E, Royal Society of Chemistry, London,1989,p.1. (b) Vicens, J.; B6hmer, V. Calixarenes. A Versatile Class of Macrocyclc Compounds, Kluwer Academic Publishers, Dordrecht,The Netherlands, 1991, p. 1. (c) McKervey, M. A.; Schwing-Weill, M.-J.; Amaud-Neu, EIn Comprehensive Supramolecular Chemistry, Vol. 1, Eds.:Atwood, J. L; Davies, J. E. D.; MacNicol, D. D.; Vǒgtle,E, Pergamon Press, Oxford, 1996, p. 537. (d) Bǒhmer, V.Angew. Chem.,Int. Ed. Engl. 1995, 34 (7), 713. (e) Danil de NaMOR,, A. E;Cleverley, R. M.; Zapata-Ormachea, M. L. Chem. Rev. 1998, 98(7), 2495.
8 Behrend, R.; Meyer, E.; Rusche, E Liebigs Ann.Chem. 1905,339, 1
9 W.A. Freeman, W. L. Mock, and N. Y. shih Cucurbituril J. Am. Chem. Soc. 1981, 103, 7367-7368
10 Kim J, Jung I S, Kim S Y, et al. New Cucurbituril Homologues: Syntheses, Isolation, Characterization, and X-ray Crystal Structures of Cucurbit[n]uril (n=5, 7, and 8). J.Am. Chem. Soc., 2000,122(3): 540-541
11 Buschmann, H.-J.; Cleve, E.; Jansen, K.; Wego, A.; SchoUeyer, E. J. Incusion Phenom. Md.??Recognit. Chem. 2001, 40, 117
12 Bushmann, H.-J.;Cleve, E.; Jansen, K.;Schoileyer, E. Anal. Chim. Acta 2001, 437, 157
13 Mock, W. L.; Shih, N.-Y. J. Org. Chem. 1983,48 (20), 3617.
14 Mock, W. L.; Shih, N.-Y. J. Org. Chem. 1986, 51 (20), 4440.
15 Mock, W. L.; Shih, N.-Y. J. Org. Chem. Soc. 1998, 110 (14), 4706.
16 Neugebauer R, Knoche W. J. Chem. Soc., Perkin Trans. 2, 1998, (3), 529.
17 WinstonO, MarielleGK, AngelE, etal. new--Cucurbit[7]uril: A Very Effective Host for Viologens andTheir Cation Radicals. Organic Letters, 2002, 4(10): 1791-1794
18 Bushmann, H.-j.; Schollmeyer, E. J. Inclusion Phenom. Mol. Recognit. Chem. 1992,14,91.
19 黎占亭，轮烷研究-从超分子组装到分子机器Chinese Journal 0fOrganic．Chemistry,2000， 20(5)，655．
20 G Schill. Catenanes,Rotaxanes,and Knots,Academic Press, New York, 1971
21 J G Chambron,G O Dietrich-Buchecker, V Heitz, J F Nierengarten,J P Sauvage, G Pascard,J Guilhem. Pure Appl.Chem.,1995,67,233
22 J P Sauvage.Acc. Chem.Res.,1998,31,611
23 D B Amabilino, J F Stoddart. Chem.Rev.1995,95,2725
24 V Balzani,M Gomez-Lopez, J F Stoddart.Acc. Chem.Res.1998,31,405
25 F V6gtle, T Dunnwald, T Schmidt.Acc.Chem.Res.,1996,29,451
26 H W Gibson,M G Bheda,P T Engen. Prog.Polym.Sci., 1994,19,843
27 G J Glarkson,D A Leigh, R A Smith.Curr.Op.Solid State and Mat.Sci.,1998,3,570
28 J Becher, Z TLi, N Svenstrup.J Jau,M B Nielsen,P Leriche.Pure.Appl.Chem., 1997,69,465
29 li, P G Stein,J Becher, D Jensen,N Svenstrp.Chem.Eur.J.,1996,2,624
30 (a)Mock, W. L. In Comprehensive Supramolecular Chemistry, Vol.2,Eds.:Atwood,J.L.;Davies,J.E.D.;MacNicol,D.D.;V6gtle,F.,Pergamon Press, Oxford, 1996, p.477. (b) Mock, W. L. Top. Curt. Chem. 1995, 175, 1. (c) Cintas, P. J. Incusion Phenom. Mol. Recognit.Chem.1994, 17, 205.
31 Jeon, Y.-M.; Whang, D.; Kim, J.; Kirn, K. Chem.Lett.1996, 503.
32 Buschmann, H.-J.; Wego, A.; Schollmeyer, E.; D6pp, D.Supramol. Chem. 2000, 11,225.33 Meschke, C.; Buschmann, H.-J.; Schollmeyer, E. Macromol.Rapid Gommun. 1998, 19, 59.
34 Sokolov, M. N.; Virovets, A. V.; Dybtsev, D. N.; Gerasko,O. A.; Fedin, V.P.;Hernandez-Molina, R.; Clegg, W.;Sykes, A. G. Angew.Chem., Int. Ed. 2000, 39, 1659.
35 Whang, D.; Jeon, Y.-M.; Heo, J.; Kim, K. J. Am. Chem. Soc. 1996, I18(45), 11333.
36 Whang, D.; Kim, K. Polycatenated Two-Dimensional Polyrotaxane Net. J. Am. Chem; Soc. 1997, 119451.
37 Whang, D.; Park, K.-M.; Heo, J.; Ashton, P.; Kim, K. J. Am. Chem. Soc. 1996, 120(19), 4899.
38 Whang, D.;Heo, J.;Kim, C.-A.;Kim, K. Chem. Commun. 1997, 2361.
39 lee, E.; Kim, J.; Heo, J.; Whang, D.; Kirn, K. Angew.Chem., Int. Ed. 2001, 40(2), 399.
40 Theodora, W. G. Productive Groups In Organic Synthesis, John Wiley & Sons Ltd., Harvard University, 1981, p. 316.
41 Meschke, C.; Buschrnann, H. J.; Schollmeyer, E. Polymer 1999, 40, 945.
42 Xu, Z. Q.; Yao, X. Q.; Xue, S. F.; Zhu, Q. J.; Tao, Z.; Zhang, J. X.; Wei, Z. B. ; Long, L. S. Acta Chim. Sinica 2004, 62, 1927 (in Chinese). (徐周庆，姚晓青，薛赛凤，祝黔江，陶朱，张建新，魏赞斌，龙腊生，化学学报，2004，62，1927)
43 Yong, G. P. ; Li, G. S. ; Yan, X. Y. ; Liu. S. M. Fine Chemical 2003, 20(1), (in Chinese). (雍国平，李光水，阎向阳，刘少民，精细化工，2003，20(1)，16)
44 Yang, S. L.; Xue, S. F.; Ma, P. H.; Zhu, Q. J.; Tao, Z.; Zhang, J. X. Chin. J. Org. Chem. 2005, 25, 1215. (杨守林，薛赛凤，马培华，祝黔江，陶朱，张建新，有机化学，2005，25，1215．
45 Xiang, S. Chuna. : Tao, Z. ; HuY. : XiangZ. M. ; Xue, S. F.; Zhu, Q. J.; Zhang, J. X. Chin. J. Org. Chem. 2005, 25, 1208. (向双春，陶朱，胡育，向章敏，薛赛凤，祝黔江，张建新，有机化学，2005，25，1208．)
46 Fu H. Y.; Xue, S. F.; Zhu, Q. J.; Tao, Z.; Zhang, J. X.; Day, A. I. Inc. Phenom. Macro. Chem. 2005, 52(1), 101.
47 (a) Sindelar, V.; Cejas, M.A.; Raymo, EM.; Kaifer, A. E. New J. Chem. 2005, 29, 280. (b) Sindelar, V.; Moon, K.; Kaifer, A. E. Org. Lett. 2004, 6, 2665. (c) Ong, W.; Kaifer, A. E. J. Org. Chem. 2004, 69, 1383. (d) Moon, K.; Kaifer, A. E. Org. Lett. 2004, 6, 185