Progress in [4＋1] Cycloadditions of Conjugated Dienes

doi:10.6023/cjoc202407043

Abstract

Five-membered ring motifs widely exist in many natural products, pharmaceuticals and organic materials, and are also important intermediates in organic synthesis and core structures for drug development. Therefore, highly efficient approaches for the synthesis of five-membered cyclic compounds are in high demand. [4＋1] cycloaddition of readily available conjugated diene provides an efficient and straightforward strategy to construct five-membered carbo- and heterocyclic compounds in an atom-economic manner, and have therefore attracted more attention from the synthetic community. In recent years, duo the significant advances in transition-metal catalysis and precursors of one-atom synthons, [4＋1] cycloadditions, which convert simple and readily accessible substrates into complex and diverse five-membered ring molecules, are rapidly growing and a series of excellent achievements have been reported. This review presents the progress in [4＋1] cycloaddition reactions of conjugated diene with various one-atom synthons involving carbon monoxide (CO), carbenes, silylenes, germylenes and nitrenes. The reactions and their mechanisms are discussed according to the types of one-atom synthons. Furthermore, the challenges and future development trends in this field are also prospected.

Key words: [4＋1] cycloaddition, conjugated diene, carbene, silylene, germylene, nitrene, five-membered cyclic compound

Cite this article

Yefei Zhang, Yong Tang, You-Yun Zhou. Progress in [4＋1] Cycloadditions of Conjugated Dienes[J]. Chinese Journal of Organic Chemistry, 2025, 45(1): 1-21.

Export EndNote|Reference Manager|ProCite|BibTeX|RefWorks

share this article

Fig. & Tab. 31

Figure 1. Natural product, pharmaceuticals and functional materials containing five-membered carbo- and heterocyclic structures

Figure 2. General strategies for the synthesis of five-membered carbo- and heterocyclic compounds

Scheme 1. Intramolecular [4＋1] cycloaddition of dienetricarbonyl iron-butadiene complexes

Scheme 2. Rh-catalyzed [4＋1] cycloadditions of cyclopropyl- caped 1,3-dienes with CO

Scheme 3. [4＋1] cycloadditions of 1,3-dienes with carbenes

Scheme 4. Rh-catalyzed [4＋1] cycloaddition of 2-siloxy-1,3-dienes with diazo compounds

Scheme 5. Generation of dimethoxycarbenes

Scheme 6. [4＋1] cycloaddition of electron-deficient dienes with dialkoxycarbenes

Scheme 7. Mechanistic pathways of intramolecular [4＋1] cycloaddition of dialkoxycarbenes

Scheme 8. Intramolecular [4＋1] cycloaddition: application to the synthesis of carotol

Scheme 9. Chiral Rh-catalyzed enantioselective formal [4＋1] cycloaddition of diazooxindoles with 1,3-dienes

Scheme 10. Enantioselective formal [4＋1] cycloaddition of diazoarylacetates with 1,3-dienes

Scheme 11. [4＋1] cycloaddition of 1,1-dibromo-2,2-diphenyl- cyclopropane with 1,3-dienes

Scheme 12. Cu(I)-catalyzed formal [4＋1] cycloaddition of 1,3-dienes with sodium bromodifluoroacetate

Scheme 13. Dinickel-catalyzed reductive [4＋1] cycloaddition of 1,1-dichloroalkenes with 1,3-dienes

Scheme 14. C2?symmetric dinickel-catalyzed enantioselective [4＋1] cycloaddition of 1,1-dichloroalkene with 1,3-dienes

Scheme 15. Formal [4＋1] cycloaddition of Fischer carbene complexes with methyl sorbate

Scheme 16. Formal [4＋1] cycloaddition of Fischer carbene complexes with 1,3-diamino-1,3-dienes

Scheme 17. Formal [4＋1] cycloaddition of Fischer carbene complexes with electronically neutral 1,3-dienes

Scheme 18. Formal [4＋1] cycloaddition of Fischer carbene complexes with 1-amino-1,3-dienes

Scheme 19. Formal intramolecular [4＋1] cycloaddition of chromium aminocarbenes

Scheme 20. Double [4＋1] cycloaddition of 1,3-butadiene with silicon tetrachloride

Scheme 21. Mechanism of [4＋1] cycloaddition of 1,3-butadi- ene with dichlorosilanes

Scheme 22. Formal [4＋1] cycloaddition of 1,1-dilithio-2,3,4,5-tetraphenylsilole with 1,3-dienes

Scheme 23. Pd-catalyzed [4＋1] cycloaddition of (aminosilyl)- boronic esters with 1,3-dienes

Scheme 24. Pd-catalyzed [4＋1] cycloaddition of (aminosilyl)boronic esters with 2-vinylindoles

Scheme 25. Synthesis of silacyclopent-3-enes by transition-metal-free diphenylsilylene transfer

Scheme 26. Ni-catalyzed reductive [4＋1] cycloaddition of dichlorosilanes with 1,3-dienes

Scheme 27. [4＋1] cycloaddition of dichlorodimethylgermane with 1,3-dienes

Scheme 28. [4＋1] Cycloaddition of 1,2-bis(ferrocenyl)digermene with 2,3-dimethyl-1,3-butadiene

Scheme 29. Cu-catalyzed formal [4＋1] cycloaddition of nitrene precursors with 1,3-dienes

References 68

[1]	(a) Das, S.; Chandrasekhar, S.; Yadav, J. S.; Gree, R. Chem. Rev. 2007, 107, 3286.
	(b) Kurteva, V. B.; Afonso, C. A. M. Chem. Rev. 2009, 109, 6809.
	(c) Vitaku, E.; Smith, D. T.; Njardarson, J. T. J. Med. Chem. 2014, 57, 10257.
	(d) Ni, H. Q.; Cooper, P.; Engle, K. M. Chem. Commun. 2021, 57, 7610.
	(e) Marshall, C. M.; Federice, J. G.; Bell, C. N.; Cox, P. B.; Njar-darson, J. T. J. Med. Chem. 2024, 67, 11622.
[2]	(a) Ohshita, J. Macromol. Chem. Phys. 2009, 210, 1360.
	(b) Dong, Z.; Albers, L.; Müller, T. Acc. Chem. Res. 2020, 53, 532.
[3]	(a) Padwa, A.; Pearson, W. H. Synthetic Applications of 1, 3-Dipolar Cycloaddition Chemistry toward Heterocycles and Natural Products, Wiley-Interscience, New York, 2002.
	For reviews: (b) Gothelf, K. V.; Jørgensen, K. A. Chem. Rev. 1998, 98, 863.
	(c) Coldham, I.; Hufton, R. Chem. Rev. 2005, 105, 2765.
	(d) Pandey, G.; Banerjee, P.; Gadre, S. R. Chem. Rev. 2006, 106, 4484.
	(e) Stanley, L. M.; Sibi, M. P. Chem. Rev. 2008, 108, 2887.
	(f) Adrio, J.; Carretero, J. C. Chem. Commun. 2011, 47, 6784.
	(g) Adrio, J.; Carretero, J. C. Chem. Commun. 2014, 50, 12434.
[4]	(a) Torres, R. R. The Pauson-Khand Reaction: Scope, Variations and Applications, Wiley-VCH, Weinheim, 2012.
	For reviews: (b) Gibson, S. E.; Stevenazzi, A. Angew. Chem., Int. Ed. 2003, 42, 1800.
	(c) Blanco-Urgoiti, J.; Anorbe, L.; Perez-Serrano, L.; Dominguez, G.; Perez-Castells, J. Chem. Soc. Rev. 2004, 33, 32.
	(d) Shibata, T. Adv. Synth. Catal. 2006, 348, 2328.
	(e) Lee, H. W.; Kwong, F. Y. Eur. J. Org. Chem. 2010, 789.
[5]	(a) Hudlicky, T.; Price, J. D. Chem. Rev. 1989, 89, 1467.
	(b) Wong, H. N. C.; Hon, M. Y.; Tse, C. W.; Yip, Y. C.; Tanko, J.; Hudlicky, T. Chem. Rev. 1989, 89, 165.
	(c) Baldwin, J. E. Chem. Rev. 2003, 103, 1197.
	(d) Baldwin, J. E.; Leber, P. A. Org. Biomol. Chem. 2008, 6, 36.
	(e) Hudlicky, T.; Reed, J. W. Angew. Chem., Int. Ed. 2010, 49, 4864.
[6]	(a) Lu, L. Q.; Zhang, J. J.; Li, F.; Cheng, Y.; An, J.; Chen, J. R.; Xiao, W. J. Angew. Chem., Int. Ed. 2010, 49, 4495.
	(b) Wang, Q.; Qi, X. T.; Lu, L. Q.; Li, T. R.; Yuan, Z. G.; Zhang, K.; Li, B. J.; Lan, Y.; Xiao, W. J. Angew. Chem., Int. Ed. 2016, 55, 2840.
	(c) Wang, Q.; Li, T. R.; Lu, L. Q.; Li, M. M.; Zhang, K.; Xiao, W. J. J. Am. Chem. Soc. 2016, 138, 8360.
	(d) Liu, H.; He, G. C.; Zhao, C. Y.; Zhang, X. X.; Ji, D. W.; Hu, Y. C.; Chen, Q. A. Angew. Chem., Int. Ed. 2021, 60, 24284.
	(e) Kong, H. H.; Zhu, C. J.; Deng, S.; Xu, G.; Zhao, R. N.; Yao, C. C.; Xiang, H. M.; Zhao, C. H.; Qi, T. T.; Xu, H. J. Am. Chem. Soc. 2022, 144, 21347.
	(f) Qu, B. L.; Shi, B.; He, L.; Shi, J. W.; Xiao, W. J.; Lu, L. Q. Org. Chem. Front. 2023, 10, 3498.
	For reviews: (g) Li, Y.; Feng, K. L.; Zhao, R. N.; Zhu, C. J.; Xu, H. Synlett 2024, 35, 1089.
[7]	(a) Murakami, M.; Itami, K.; Ito, Y. Angew. Chem., Int. Ed. Engl. 1996, 34, 2691.
	(b) Murakami, M.; Itami, K.; Ito, Y. J. Am. Chem. Soc. 1997, 119, 2950.
	(c) Murakami, M.; Itami, K.; Ito, Y. Organometallics 1999, 18, 1326.
	(d) Murakami, M.; Itami, K.; Ito, Y. J. Am. Chem. Soc. 1999, 121, 4130.
	(e) Chatani, N. In Ruthenium Catalysts and Fine Chemistry, Vol. 11, Eds.: Bruneau, C.; Dixneuf, P., Springer, Berlin Heidelberg, 2004.
	(f) Kollar, L. Modern Carbonylation Methods, Wiley-VCH, Weinheim, 2008.
	For a review: (g) Li, C. L.; Yu, Z. X. Chin. J. Org. Chem. 2024, 44, 1045 (in Chinese).
	(李晨龙, 余志祥, 有机化学, 2024, 44, 1045.)
[8]	Frühauf, H. W. Chem. Rev. 1997, 97, 523.
[9]	Johnson, B. F. G.; Lewis, J.; Thompson, D. J. Tetrahedron Lett. 1974, 15, 3789.
[10]	(a) Franck-Neumann, M.; Vernier, J. M. Tetrahedron Lett. 1992, 33, 7361.
	(b) Franck-Neumann, M.; Michelotti, E. L.; Simler, R.; Vernier, J. M. Tetrahedron Lett. 1992, 33, 7365.
[11]	Yang, Y. S.; Li, H. X.; Zhu, Y. T.; Zhang, Z. Y.; Yu, Z. X. J. Am. Chem. Soc. 2023, 145, 17087.
[12]	Chen, J. R.; Hu, X. Q.; Lu, L. Q.; Xiao, W. J. Chem. Rev. 2015, 115, 5301.
[13]	(a) Fujimoto, H.; Hoffmann, R. J. Phys. Chem. 1974, 78, 1167.
	(b) Schoeller, W. W.; Yurtsever, E. J. Am. Chem. Soc. 1978, 100, 7548.
	(c) Bauld, N. L.; Wirth, D. J. Comput. Chem. 1981, 2, 1.
	(d) Moss, R. A.; Jones, M. Jr. In Reactive Intermediates, Vol. 2, Wiley, New York, 1981, Chapter 3.
	(e) Schoeller, W. W.; Aktekin, N. J. Chem. Soc., Chem. Commun. 1982, 20.
	(f) Evanseck, J. D.; Mareda, J.; Houk, K. N. J. Am. Chem. Soc. 1990, 112, 73.
[14]	Schnaubelt, J.; Marks, E.; Reibig, H. U. Chem. Ber. 1996, 129, 73.
[15]	(a) Salomon, R. G., Salomon, M. E.; Kachinsky, J. L. C. J. Am. Chem. Soc. 1977, 99, 1043.
	(b) Doyle, M. P.; Van Leusen, D. J. Am. Chem. Soc. 1981, 103, 5917.
	(c) Hudlicky, T.; Kutchan, T. M.; Naqvi, S. M. Org. React. 1985, 33, 247.
[16]	Hofmann, B.; Reibig, H. U. Chem. Ber. 1994, 127, 2315.
[17]	(a) Davies, H. M. L.; Hu, B.; Saikali, E.; Brazinski, P. R. J. Org. Chem. 1994, 59, 4535.
	(b) Trost, B. M.; Hashmi, A. S. K. J. Am. Chem. Soc. 1994, 116, 2183.
	(c) Hoffmann, M. Ph.D. Dissertation, Technische Universität, Dresden, 1994.
[18]	Arduengo III, A. J.; Harlow, R. L.; Kline, M. J. Am. Chem. Soc. 1991, 113, 361.
[19]	Moss, R. A.; Wtostowski, M.; Shen, S.; Krogh-Jespersen, K.; Matro, A. J. Am. Chem. Soc. 1988, 110, 4443.
[20]	(a) Warkentin, J. Acc. Chem. Res. 2009, 42, 205.
	(b) Warkentin, J. In Advances in Carbene Chemistry, Vol. 2, Ed.:Brinker, U. H., JAI Press, Greenwich, 1998, pp. 245-295.
[21]	(a) Moss, R. A.; Cox, D. P. Tetrahedron Lett. 1985, 26, 1931.
	(b) Olofson, R. A.; Walinsky, S. W.; Marino, J. P.; Jernow, J. L. J. Am. Chem. Soc. 1968, 90, 6554.
	(c) Sheeren, J. W.; Slaps, R. J. F. M.; Nivard, R. J. F. Recl. Trav. Chim. Pays-Bas 1973, 92, 11.
	(d) Corey, E. J.; Winter, R. A. E. J. Am. Chem. Soc. 1963, 85, 2677.
[22]	El-Saidi, M. Kassam, K.; Pole, D-L.; Tadey, T.; Warkentin, J. J. Am. Chem. Soc. 1992, 114, 8751.
[23]	Spino, C.; Rezaei, H.; Dupont-Gaudet, K.; Bélanger, F. J. Am. Chem. Soc. 2004, 126, 9926.
[24]	Boisvert, C.; Beaumier, F.; Spino, C. Org. Lett. 2007, 9, 5361.
[25]	Beaumier, F.; Dupuis, M.; Spino, C.; Legault, C.-L. J. Am. Chem. Soc. 2012, 134, 5938.
[26]	Gund, M.; Déry, M.; Amzallag, V.; Spino, C. Org. Lett. 2016, 18, 4280.
[27]	Cao, F.; Hu, F.; Xie, Q. M.; Luo, G. Y.; Chu, W. D.; He, L.; Liu, Q. Z. Asian J. Org. Chem. 2018, 7, 363.
[28]	(a) Wulff, W. D.; Yang, D. C.; Murray, C. K. Pure Appl. Chem. 1988, 60, 137.
	(b) Rodriguez, K. X.; Kaltwasser, N.; Toni, T. A.; Ashfeld, B. L. Org. Lett. 2017, 19, 2482.
	(c) Meloche, J. L.; Ashfeld, B. L. Angew. Chem., Int. Ed. 2017, 56, 6604.
[29]	Hu, F.; Zhou, Q.; Cao, F.; Chu, W. D.; He, L.; Liu, Q. Z. J. Org. Chem. 2018, 83, 12806.
[30]	(a) Simmons, H. E.; Smith, R. D. J. Am. Chem. Soc. 1958, 80, 5323.
	(b) Simmons, H. E.; Smith, R. D. J. Am. Chem. Soc. 1959, 81, 4256.
	(c) Simmons, H. E.; Cairns, T. L.; Vladuchick, S. A.; Hoiness, C. M. Org. React. 1973, 20, 1.
	(d) Charette, A. B. Beauchemin, A. Org. React. 2001, 58, 1.
[31]	Sugita, H.; Mizuno, K.; Mori, T.; Isagawa, K.; Otsuji, Y. Angew. Chem., Int. Ed. Engl. 1991, 30, 984.
[32]	Fuchibe, K.; Aono, T.; Hu, J.; Ichikawa, J. J. Org. Lett. 2016, 18, 4502.
[33]	Zhou, Y. Y.; Uyeda, C. Science 2019, 363, 857.
[34]	Behlen, M. J.; Uyeda, C. J. Am. Chem. Soc. 2020, 142, 17294.
[35]	Yoon, T. P.; Jacobsen, E. N. Science 2003, 299, 1691.
[36]	Fischer, E. O.; Maasböl, A. Angew. Chem., Int. Ed. Engl. 1964, 3, 580.
[37]	(a) Hegedus, L. S. Tetrahedron 1997, 53, 4105.
	(b) Barluenga, J.; Fañanas, F. J. Tetrahedron 2000, 56, 4597.
	(c) Barluenga, J.; Fernandez-Rodríguez, M. A. J. Organomet. Chem. 2005, 690, 539.
	For reviews, see: (d) Ed.: Dörwald, F. Z. Metal Carbenes in Organic Synthesis, Wiley-VCH, Weinheim, 2008.
	(e)Metal Carbenes in Organic Synthesis, Vol. 13, Ed.: Dötz, K. H., Berlin, Springer, 2004.
	(f) Dotz, K. H.; Stendel, J. Chem. Rev. 2009, 109, 3227.
[38]	Sierra, M. A.; Soderberg, B.; Lander, P. A.; Hegedus, L. S. Organo- metallics 1993, 12, 3769.
[39]	Barluenga, J.; Aznar, F.; Fernandez, M. Chem.-Eur. J. 1997, 3, 1629.
[40]	Buchert, M.; Hoffmann, M.; Reibig, H. U. Chem. Ber. 1995, 128, 605.
[41]	Barluenga, J.; Lopez, S.; Florez, J. Angew. Chem., Int. Ed. 2003, 42, 231.
[42]	(a) Hoffmann, M.; Buchert, M.; Reissig, H. U. Angew. Chem., Int. Ed. Engl. 1997, 36, 283.
	(b) Hoffmann, M.; Buchert, M.; Reissig, H. U. Chem.-Eur. J. 1999, 5, 876.
[43]	Kagoshima, H.; Okamura, T.; Akiyama, T. J. Am. Chem. Soc. 2001, 123, 7182.
[44]	Aznar, F. Fananas-Mastral, M.; Alonso, J.; Fananas, F. J. Chem.- Eur. J. 2008, 14, 325.
[45]	Dery, M.; Lefebvre, L. P.; Aissa, K.; Spino, C. Org. Lett. 2013, 15, 5456.
[46]	(a) Horvath, R. F.; Chan, T. H. J. Org. Chem. 1987, 52, 4489.
	(b) Liu, D.; Kozmin, S. A. Angew. Chem., Int. Ed. 2001, 40, 4757.
	(c) Sen, S.; Purushotham, M.; Qi, Y.; Sieburth, S. M. Org. Lett. 2007, 9, 4963.
	(d) Singh, S.; Sieburth, S. M. Org. Lett. 2012, 14, 4422.
	For a review see: (e) Hermanns, J.; Schmidt, B. J. Chem. Soc., Perkin Trans. 1 1999, 81.
[47]	(a) Igawa, K.; Yoshihiro, D.; Abe, Y.; Tomooka, K. Angew. Chem., Int. Ed. 2016, 55, 5814.
	(b) Igawa, K.; Kuroo, A.; Yoshihiro, D.; Yamanaka, Y.; Tomooka, K. Synlett 2017, 28, 2445.
	(c) Morontsev, A.; Gringolts, M.; Lakhtin, V.; Finkelshtein, E. J. Organomet. Chem. 2020, 911, 121156.
[48]	Salomon, R. G. J. Org. Chem. 1974, 39, 3602.
[49]	Dunogues, J.; Calas, R.; Dedier, J.; Pisciotti, F.; Lapouyade, P. J. Organomet. Chem. 1970, 25, 51.
[50]	(a) Beteille, J. P.; Clarke, M. P.; Davidson, I. M. T.; Dubac, J. Organometallics 1989, 8, 1292.
	(b) Nagao, Y.; Takahashi, M.; Abe, Y.; Misono, T.; Jung, M. E. Bull. Chem. Soc. Jpn. 1993, 66, 2294.
	(c) Jiang, P.; Gaspar, P. P. J. Am. Chem. Soc. 2001, 123, 8622.
	(d) Nagao, Y.; Kimura, C.; Kozawa, K.; Jung, M. E. Silicon Chem. 2003, 2, 99.
[51]	Richter, W. J. J. Organomet. Chem. 1985, 289, 45.
[52]	Zhang, S.; Conlin, R. T. J. Am. Chem. Soc. 1991, 113, 4272.
[53]	(a) Hwang, R.-J.; Conlin, R. T.; Gaspar, P. P. J. Organomet. Chem. 1975, 94, C38.
	(b) Sakurai, H.; Kobayashi, Y.; Sato, R.; Nakadaira, Y. Chem. Lett. 1983, 12, 1197.
	(c) Bobbitt, K. L.; Gaspar, P. P. J. Organomet. Chem. 1995, 499, 17.
[54]	(a) Gaspar, P. P.; Hwang, R. J. J. Am. Chem. Soc. 1974, 96, 6198.
	(b) Conlin, R. T.; Peterson, L. L. J. Organomet. Chem. 1982, 232, C71.
	(c) Lei, D.; Hwang, R.-J.; Gaspar, P. P. J. Organomet. Chem. 1984, 271, 1.
[55]	(a) Corriu, R.; Lanneau, G.; Priou, C.; Soulairol, F.; Auner, N.; Probst, R.; Conlin, R.; Tan, C. J. Organomet. Chem. 1994, 466, 55.
	(b) Tamao, K.; Nagata, K.; Asahara, M.; Kawachi, A.; Ito, Y.; Shiro, M. J. Am. Chem. Soc. 1995, 117, 11592.
	(c) Belzner, J.; Ihmels, H.; Kneisel, B. O.; Gould, R. O.; Herbst-Irmer, R. Organometallics 1995, 14, 305.
	(d) Takeda, N.; Tokitoh, N.; Okazaki, R. Chem. Lett. 2000, 29, 622.
[56]	Toulokhonova, I. S.; Friedrichsen, D. R.; Hill, N. J.; Müller, T.; West, R. Angew. Chem., Int. Ed. 2006, 45, 2578.
[57]	Ohmura, T.; Masuda, K.; Takase, I.; Suginome, M. J. Am. Chem. Soc. 2009, 131, 16624.
[58]	Masuda, K.; Ohmura, T.; Suginome, M. Organometallics 2011, 30, 1322.
[59]	Sasaki, I.; Maebashi, A.; Li, J.; Ohmura, T.; Suginome, M. Eur. J. Org. Chem. 2022, e202101573.
[60]	Appler, H.; Neumann, W. P. J. Organomet. Chem. 1986, 314, 261.
[61]	Qi, L. L.; Pan, Q. Q.; Wei, X. X.; Pang, X. B.; Liu, Z. T.; Shu, X. Z. J. Am. Chem. Soc. 2023, 145, 13008.
[62]	Neumann, W. P. Chem. Rev. 1991, 91, 311.
[63]	Lei, D. Q.; Gaspar, P. P. Polyhedron 1991, 10, 1221.
[64]	Sasamori, T.; Miyamoto, H.; Sakai, H.; Furukawa, Y.; Tokitoh, N. Organometallics 2012, 31, 3904.
[65]	(a) Dequirez, G.; Pons, V.; Dauban, P. Angew. Chem., Int. Ed. 2012, 51, 7384.
	(b) Ju, M.; Schomaker, J. M. Nat. Rev. Chem. 2021, 5, 580.
	(c) Wang, Y. C.; Lai, X. J.; Huang, K. K.; Yadav, S.; Qiu, G. Y. S.; Zhang, L. P.; Zhou, H. W. Org. Chem. Front. 2021, 8, 1677.
[66]	Wu, Q.; Hu, J.; Ren, X. F.; Zhou, J. R. Chem.-Eur. J. 2011, 17, 11553.
[67]	Brichacek, M.; Villalobos, M.; Plichta, N. A.; Njardarson, J. T. Org. Lett. 2011, 13, 1110.
[68]	(a) Mimura, N.; Ibuka, T.; Akaji, M.; Miwa, Y.; Taga, T.; Nakai, K.; Tamamura, H.; Fujii, N.; Yamamoto, Y. Chem. Commun. 1996, 351.
	(b) Ibuka, T.; Mimura, N.; Aoyama, H.; Akaji, M.; Ohno, H.; Miwa, Y.; Taga, T.; Nakai, K.; Tamamura, H.; Fujii, N.; Yamamoto, Y. J. Org. Chem. 1997, 62, 999.

共轭二烯参与的[4＋1]环加成反应研究进展