铜催化N-O键断裂策略研究进展

doi:10.6023/cjoc201904037

摘要/Abstract

N-O键断裂反应是向化合物中引入含氮、氧官能团的有效策略之一.铜催化剂来源丰富，价格便宜，铜催化剂在有机合成中占有不可替代的地位.铜催化的N-O断裂，由于具有反应条件温和、官能团兼容性好、原子经济性高等优点，在有机合成中被广泛应用于构建C-N和C-O键.N-O键的断裂策略在复杂天然产物及药物分子的合成中都有成功的应用.综述了近些年来铜金属催化N-O断裂的新策略及N-O断裂策略在天然产物和药物分子合成中的应用.

关键词: 铜催化, 杂环化合物, N-O断裂, 串联反应, 重排反应

N-O bond cleavage is one of the most efficient and powerful strategies to introduce N-or O-functional groups into molecules in organic synthesis. Copper catalyst, as the abundant in earth and inexpensive advantages has been widely used to construct C-N and C-O bond. Furthermore, N-O bond cleavage has been successfully applied in the total synthesis of natural products and pharmaceuticals. The new development of copper-catalyzed N-O bond cleavage and its application in the total synthesis of natural products and pharmaceuticals in recent years have been summarized.

Key words: copper-catalysis, heterocyclic compounds, N-O cleavage, cascade reaction, rearrangement reaction

引用此文

雷禄, 李承璟, 莫冬亮. 铜催化N-O键断裂策略研究进展[J]. 有机化学, 2019, 39(11): 2989-3012.

Lei Lu, Li Chengjing, Mo Dongliang. Recent Advances in Copper-Catalyzed N-O Cleavage Strategy[J]. Chinese Journal of Organic Chemistry, 2019, 39(11): 2989-3012.

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图/表 37

图式 1. N—O键断裂方式

Scheme 1. Type of N—O bond cleavage

表 1. 铜催化三组分串联反应合成多取代吡啶化合物

Figure 1. Copper-catalyzed three component cascade reaction to prepare polysubstituted pyridines

图式 2. 铜催化三组分串联反应合成吡啶机理

Scheme 2. Proposed mechanism of copper-catalyzed three component cascade reaction

图式 3. 铜催化肟乙酸酯氧化偶联反应

Scheme 3. Coupling reaction of copper-catalyzed oxime acetates oxidative

图式 4. 铜催化[3+3]反应合成含氟吡啶或吡啶酮

Scheme 4. Copper-catalyzed [3+3] reaction to synthesize pyridines or pyridones containing fluoro-atom

图式 5. 铜催化[3+3]反应合成含氟吡啶或吡啶酮反应机理

Scheme 5. Proposed mechanism for copper(Ⅰ)-catalyzed [3+3] reaction to synthesize pyridines or pyridones containing fluoro-atom

图式 6. 铜催化N—O断裂和环化串联反应

Scheme 6. Copper-catalyzed N—O bond cleavage and annulation cascade reaction

图式 7. 铜催化N—O键断裂参与环加成反应

Scheme 7. Copper-catalyzed N—O bond cleavage and cycloaddition

图式 8. 铜催化胺化反应机理

Scheme 8. Proposed mechanism for copper-catalyzed amination of alkenes

图式 9. 铜催化N—O键断裂不对称合成吡咯啉

Scheme 9. Copper-catalyzed N—O bond cleavage to synthesize chiral pyrrolines

表 2. 铜催化N—O/C—C键断裂合成烷基腈

Table 1. Copper-catalyzed N—O/C—C bond cleavage to synthesize alkylnitriles

图式 10. 铜催化N—O/C—C键断裂合成烷基腈反应机理

Scheme 10. Proposed mechanism of copper-catalyzed N—O/ C—C bond cleavage to synthesize alkylnitriles

图式 11. 铜催化N—O/C—C键断裂合成烷基腈

Scheme 11. Copper-catalyzed N—O/C—C bond cleavage to synthesize alkylnitriles

图式 12. 铜催化活性烯烃的氰基烷基化反应

Scheme 12. Copper-catalyzed cyanoalkylarylation of activated alkenes

图式 13. 铜催化N—O键/C—C键断裂合成硫醚化合物

Scheme 13. Copper-catalyzed N—O/C—C bond cleavage to synthesize thioether compounds

图式 14. 铜/光催化N—O/C—C键断裂合成烷基腈

Scheme 14. Copper/visible light-catalyzed N—O/C—C bond cleavage to synthesize alkylnitriles

图式 15. 铜催化肟酯和三氟甲磺酸盐的反应

Scheme 15. Copper-catalyzed oxime ester with trifluoromethyl- sulfonate reaction

图式 16. 铜催化N—O键断裂/C—S键形成合成多取代氮杂环丁烷

Scheme 16. Copper-catalyzed N—O bond cleavage/C—S bond formation to synthesize substituted azetidines

图式 17. 铜催化N-芳基硝酮重排反应合成α, β-环氧亚胺化合物

Figure 1. Copper-catalyzed N-aryl nitrones to synthesize α, β-epoxyketimines

图式 18. 铜或金催化叠氮二炔可控合成N杂环

Scheme 18. Copper or gold catalyzed azido-diynes to synthesize controllable N-heterocycles

表 3. 铜/铁共催化N—O键断裂合成吡咯稠环衍生物

Table 3. Cu/Fe-cocatalyzed N—O bond cleavage to synthesize fused pyrroles

表 4. 铜催化氮杂九元环的动力学拆分

Table 4. Copper-catalyzed kinetic resolution of nine-membered N-heterocycles

表 5. 铜/铁催化N—O键断裂生成吡咯化合物

Table 5. Cu/Fe-cocatalzyed N—O bond cleavage to synthesize pyrroles

表 6. 钴/铜共催化C—H键活化反应

Table 6. Co/Cu-cocatalzyed C—H bond activation

表 7. Cu催化N—O键断裂合成喹啉

Table 7. Copper-catalyzed N—O bond cleavage to synthesize quinolones

图式 19. Cu(Ⅱ)催化N—O键断裂合成喹啉反应机理

Scheme 19. Proposed mechanism of copper (Ⅱ)-catalyzed N—O bond cleavage to synthesize quinolines

图式 20. N—O键断裂合成2, 2-联吡啶化合物

Scheme 20. synthesis of 2, 2-bipyridines via N—O bond cleavage

表 8. 铜催化N—O键断裂合成N-烯基环氧亚胺

Table 8. Copper-catalyzed N—O cleavage to prepare N-alkenyl oxiranylketimines

图式 21. 铜催化N—O键断裂合成N-烯基环氧亚胺机理

Scheme 21. Proposed mechanism of copper-catalyzed N—O bond cleavage to prepare N-alkenyl oxiranylketimines

图式 22. 铜催化区域选项性未活化末端烯烃胺硼化

Scheme 22. Copper-catalyzed regiodivergent aminoboration of unactivated terminal alkenes

表 9. 铜催化苯并呋喃不对称去芳构化反应

Table 9. Copper-catalyzed asymmetric dearomatization of benzofurans

表 10. 铜催化烯烃不对称胺氢化反应

Table 10. Copper-catalyzed asymmetric hydrogenamination of alkenes

表 11. 铑/铜共催化C—H键活化反应

Table 11. Rh/Copper-cocatalzyed C—H bond activation

图式 23. N—O键断裂全合成Ezetimibe

Scheme 23. N—O bond cleavage to total synthesis of ezetimibe

图式 24. N—O键断裂全合成gelsemoxonine

Scheme 24. N—O bond cleavage to total synthesis of gelsemoxonine

图式 25. N—O键断裂全合成Palhinines A和D

Scheme 25. N—O bond cleavage to total synthesis of palhinines A and D

图式 26. N—O键断裂全合成huperzine R

Scheme 26. N—O bond cleavage to total synthesis of huperzine R

参考文献 94

[1]	Bolotin D. S. Bokach N. A. Demakova M. Y. Kukushkin V. Y. Chem. Rev. 2017 117 13039. doi: 10.1021/acs.chemrev.7b00264
[2]	(a) Jiao, Y.-X.; Ma, X.-P.; Su, G.-F.; Mo, D.-L. Synthesis. 2017, 49, 933. doi: 10.1055/s-0036-1588352
	(b) Chen, N.; Xie, J. Org. Biomol. Chem. 2016, 14, 11028. doi: 10.1055/s-0036-1588352
[3]	(a) Shi, W.-M.; Ma, X.-P.; Su, G.-F.; Mo, D.-L. Org. Chem. Front. 2016, 3, 116. doi: 10.1039/C5QO00122F
	(b) Murahashi, S.-I.; Imada, Y. Chem. Rev. 2019, 119, 4684. doi: 10.1039/C5QO00122F
[4]	Lu D.-F. Zhu C.-L. Jia Z.-X. Xu H. J. Am. Chem. Soc. 2014 136 13186. doi: 10.1021/ja508057u
[5]	Senadi G. C. Lu T.-Y. Dhandabani G. K. Wang J.-J. Org. Lett. 2017 19 1172. doi: 10.1021/acs.orglett.7b00208
[6]	Neely J. M. Rovis T. J. Am. Chem. Soc. 2013 135 66. doi: 10.1021/ja3104389
[7]	Yeom H.-S. Shin S. Acc. Chem. Res. 2014 47 966. doi: 10.1021/ar4001839
[8]	(a) Yao, C.-Z.; Xiao, Z.-F.; Liu, J.; Ning, X.-S.; Kang, Y.-B. Org. Lett. 2014, 16, 2498. doi: 10.1021/ol500869p
	(b) Kumar, C. V. S.; Ramana, C. V. Org. Lett. 2015, 17, 2870. doi: 10.1021/ol500869p
[9]	(a) Zhou, J.; Shi, J.; Qi, Z.; Li, X.; Xu, H. E.; Yi, W. ACS Catal. 2015, 5, 6999. doi: 10.1021/acscatal.5b01571
	(b) Xia, J.; Yang, X.; Li, Y.; Li, X. Org. Lett. 2017, 19, 3242. doi: 10.1021/acscatal.5b01571
[10]	Nakamura I. Sato Y. Terada M. J. Am. Chem. Soc. 2009 131 4198. doi: 10.1021/ja900174t
[11]	Sivakumar G. Vijeta A. Jeganmohan M. Chem. Eur. J. 2016 22 5899. doi: 10.1002/chem.201600471
[12]	Liu X.-G. Gao H. Zhang S.-S. Li Q. Wang H. ACS Catal. 2017 7 5078. doi: 10.1021/acscatal.7b00677
[13]	(a) Yang, H.-B.; Pathipati, S. R.; Selander, N. ACS Catal. 2017, 7, 8441. doi: 10.1021/acscatal.7b03432
	(b) Ding, D.; Wang, C. ACS Catal. 2018, 8, 111324. doi: 10.1021/acscatal.7b03432
[14]	Tang X. Wu W. Zeng W. Jiang H. Acc. Chem. Res. 2018 51 1092. doi: 10.1021/acs.accounts.7b00611
[15]	(a) Ma, X.-P.; Liu, F.-P.; Mo, D.-L. Chin. J. Org. Chem. 2017, 37, 1069 (in Chinese). doi: 10.6023/A14120888
	(b) Lu, Q.; Yi, H.; Lei, A. Acta Chim. Sinica 2015, 73, 1245. doi: 10.6023/A14120888
	(c) Zhang, J.; Lu, Q.; Liu, C.; Lei, A. Chin. J. Org. Chem. 2015, 35, 743 (in Chinese). doi: 10.6023/A14120888
[16]	(a) Ma, D.; Cai, Q. Acc. Chem. Res. 2008, 41, 1450. doi: 10.1021/ar8000298
	(b) McCann, S. D.; Stahl, S. S. Acc. Chem. Res. 2015, 48, 1756. doi: 10.1021/ar8000298
[17]	Dong X. Liu Q. Dong Y. Liu H. Chem. Eur. J. 2017 23 2481. doi: 10.1002/chem.201601607
[18]	Jiang H. Yang J. Tang X. Li J. Wu W. J. Org. Chem. 2015 80 8763. doi: 10.1021/acs.joc.5b01621
[19]	Fu Y. Wang P. Guo X. Wu P. Meng X. Chen B. J. Org. Chem. 2016 81 11671. doi: 10.1021/acs.joc.6b02081
[20]	Tan W. W. Ong Y. J. Yoshikai N. Angew. Chem. Int. Ed. 2017 56 8240. doi: 10.1002/anie.201704378
[21]	Bai D. Wang X. Zheng G. Li X. Angew. Chem. Int. Ed. 2018 57 6633. doi: 10.1002/anie.201802311
[22]	Jiang H. Yang J. Tang X. Wu W. J. Org. Chem. 2016 81 2053. doi: 10.1021/acs.joc.5b02914
[23]	Ramaraju A. Chouhan N. K. Ravi O. Sridhar B. Bathula S. R. Eur. J. Org. Chem. 2018 2963.
[24]	Huang H. Cai J. Ji X. Xiao F. Chen Y. Deng G.-J. Angew. Chem. Int. Ed. 2016 55 307. doi: 10.1002/anie.201508076
[25]	Zhao B. Liang H.-W. Yang J. Yang Z. Wei Y. ACS Catal. 2017 7 5612. doi: 10.1021/acscatal.7b01876
[26]	Zhu C. Zhu R. Zeng H. Chen F. Liu C. Wu W. Jiang H. Angew. Chem. Int. Ed. 2017 56 13324. doi: 10.1002/anie.201707719
[27]	Yang J. Zhao B. Xi Y. Sun S. Yang Z. Ye Y. Jiang K. Wei Y. Org. Lett. 2018 20 1216. doi: 10.1021/acs.orglett.8b00141
[28]	Xie Y. Li Y. Chen X. Liu Y. Zhang W. Org. Chem. Front. 2018 5 1698. doi: 10.1039/C8QO00204E
[29]	Dai X.-J. Engl O. D. León T. Buchwald S. L. Angew. Chem. Int. Ed. 2019 58 3407. doi: 10.1002/anie.201814331
[30]	Zhao B. Shi Z. Angew. Chem. Int. Ed. 2017 56 12727. doi: 10.1002/anie.201707181
[31]	Ai W. Liu Y. Wang Q. Lu Z. Liu Q. Org. Lett. 2018 20 409. doi: 10.1021/acs.orglett.7b03707
[32]	Zhu C. Chen F. Liu C. Zeng H. Yang Z. Wu W. Jiang H. J. Org. Chem. 2018 83 14713. doi: 10.1021/acs.joc.8b02103
[33]	An Z. Jiang Y. Guan X. Yan R. Chem. Commun. 2018 54 10738. doi: 10.1039/C8CC06256K
[34]	Wu J. Zhang J.-Y. Gao P. Xu S.-L. Guo L.-N. J. Org. Chem. 2018 83 1046. doi: 10.1021/acs.joc.7b02714
[35]	He M. Yan Z. Zhu F. Lin S. J. Org. Chem. 2018 83 15438. doi: 10.1021/acs.joc.8b02707
[36]	Yu X.-Y. Zhao Q.-Q. Chen J. Chen J.-R. Xiao W.-J. Angew. Chem. Int. Ed. 2018 57 15505. doi: 10.1002/anie.201809820
[37]	Wang P. Zhao B. Yuan Y. Shi Z. Chem. Commun. 2019 55 1971. doi: 10.1039/C8CC10109D
[38]	He Y. Lou J. Wu K. Wang H. Yu Z. J. Org. Chem. 2019 84 2178. doi: 10.1021/acs.joc.8b03175
[39]	Min Q.-Q. Li N. Chen G.-L. Liu F. Org. Chem. Front. 2019 6 1200. doi: 10.1039/C9QO00235A
[40]	Tang X. Zhu Z. Qi C. Wu W. Jiang H. Org. Lett. 2016 18 180. doi: 10.1021/acs.orglett.5b03188
[41]	Tang X. Yan J. Zhu Z. Zheng M. Wu W. Jiang H. J. Org. Chem. 2016 81 11461. doi: 10.1021/acs.joc.6b02124
[42]	Zhu Z. Tang X. Cen J. Li J. Wu W. Jiang H. Chem. Commun. 2018 54 3767. doi: 10.1039/C8CC00445E
[43]	Zhou P. Huang Y. Wu W. Yu W. Li J. Zhu Z. Jiang H. Org. Biomol. Chem. 2019 17 3424. doi: 10.1039/C9OB00377K
[44]	Liu H. Yan X. Chen C. Liu Q. Xi C. Chem. Commun. 2013 49 5513. doi: 10.1039/c3cc41574k
[45]	Zhu Z. Tang X. Li J. Li X. Wu W. Deng G. Jiang H. Chem. Commun. 2017 53 3228. doi: 10.1039/C7CC00260B
[46]	Yang H.-B. Selander N. Org. Biomol. Chem. 2017 15 1771. doi: 10.1039/C7OB00203C
[47]	Xu L.-L. Wang X. Ma B. Yin M.-X. Lin H.-X. Dai H.-X. Yu J.-Q. Chem. Sci. 2018 9 5160. doi: 10.1039/C8SC01256C
[48]	Ren Z.-H. Zhao M.-N. Yi Y. Wang Y.-Y. Guan Z.-H. Synthesis 2016 48 1920. doi: 10.1055/s-0035-1561950
[49]	Zhu C. Zeng H. Chen F. Liu C. Zhu R. Wu W. Jiang H. Org. Chem. Front. 2018 5 571. doi: 10.1039/C7QO00874K
[50]	Ke J. Tang Y. Yi H. Li Y. Cheng Y. Liu C. Lei A. Angew. Chem. Int. Ed. 2015 54 6604. doi: 10.1002/anie.201501287
[51]	Reidl T. W. Son J. Wink D. J. Anderson L. L. Angew. Chem. Int. Ed. 2017 56 11579. doi: 10.1002/anie.201705681
[52]	He M. Yan Z. Wang W. Zhu F. Lin S. Tetrahedron Lett. 2018 59 3706. doi: 10.1016/j.tetlet.2018.09.007
[53]	Mo D.-L. Anderson L. L. Angew. Chem. 2013 52 6722. doi: 10.1002/anie.201301963
[54]	Yan H. Wang H. Li X. Xin X. Wang C. Wan B. Angew. Chem. Int. Ed. 2015 54 10613. doi: 10.1002/anie.201503997
[55]	Wolosewicz K. Michalak M. Adamek J. Furman B. Eur. J. Org. Chem. 2016 2212.
[56]	Son J. Kim K. H. Mo D.-L. Wink D. J. Anderson L. L. Angew. Chem. Int. Ed. 2017 56 3059. doi: 10.1002/anie.201611791
[57]	Kong Y. Liu Y. Wang B. Li S. Liu L. Chang X. Li J. Adv. Synth. Catal. 2018 360 1240. doi: 10.1002/adsc.201701476
[58]	Hasegawa M. Nomoto A. Soeta T. Ukaji Y. Chem. Lett. 2017 46 45. doi: 10.1246/cl.160821
[59]	Shen W.-B. Sun Q. Li L. Liu X. Zhou B. Yan J.-Z. Lu X. Ye L.-W. Nat. Commun. 2017 8 1748. doi: 10.1038/s41467-017-01853-1
[60]	Liu X. Zhang Z.-X. Zhou B. Wang Z.-S. Zheng R.-H. Ye L.-W. Org. Biomol. Chem. 2017 15 10156. doi: 10.1039/C7OB02728A
[61]	Wang Z. Han M.-Y. Li P. Wang L. Eur. J. Org. Chem. 2018 5954.
[62]	Tian Z. Xu J. Liu B. Tan Q. Xu B. Org. Lett. 2018 20 2603. doi: 10.1021/acs.orglett.8b00798
[63]	Zou N. Jiao J.-W. Feng Y. Pan C.-X. Liang C. Su G.-F. Mo D.-L. Org. Lett. 2019 21 481. doi: 10.1021/acs.orglett.8b03767
[64]	Ma X.-P. Li L.-G. Zhao H.-P. Du M. Liang C. Mo D.-L. Org. Lett. 2018 20 4571. doi: 10.1021/acs.orglett.8b01761
[65]	Hu F. Szostak M. Adv. Synth. Catal. 2015 357 2583. doi: 10.1002/adsc.201500319
[66]	Li L. Tan T.-D. Zhang Y.-Q. Liu X. Ye L.-W. Org. Biomol. Chem. 2017 15 8483. doi: 10.1039/C7OB01895A
[67]	Li L. Wang H. Yu S. Wang X. Li X. Org. Lett. 2016 18 3662. doi: 10.1021/acs.orglett.6b01716
[68]	Biswas A. Karmakar U. Nandi S. Samanta R. J. Org. Chem. 2017 82 8933. doi: 10.1021/acs.joc.7b01343
[69]	Guo S. Yang C. J. Buchwald S. L. J. Am. Chem. Soc. 2018 140 15976. doi: 10.1021/jacs.8b10564
[70]	Xie F. Shen B. Li X. Org. Lett. 2018 20 7154. doi: 10.1021/acs.orglett.8b03093
[71]	Wang F. Xu P. Wang S.-Y. Ji S.-J. Org. Lett. 2018 20 2204. doi: 10.1021/acs.orglett.8b00525
[72]	Sheng J. He R. Xue J. Wu C. Qiao J. Chen C. Org. Lett. 2018 20 4458. doi: 10.1021/acs.orglett.8b01748
[73]	Galenko E. E. Novikov M. S. Shakirova F. M. Shakirova J. R. Kornyakov I. V. Bodunov V. A. Khlebnikov A. F. J. Org. Chem. 2019 84 3524. doi: 10.1021/acs.joc.9b00115
[74]	Nakamura I. Iwata T. Zhang D. Terada M. Org. Lett. 2012 14 206. doi: 10.1021/ol203001w
[75]	Nakamura I. Kudo Y. Terada M. Angew. Chem. Int. Ed. 2013 52 7536. doi: 10.1002/anie.201302751
[76]	Nakamera I. Ishida Y. Terada M. Org. Lett. 2014 16 2562. doi: 10.1021/ol5009608
[77]	Zhang D. Nakamura I. Terada M. Org. Lett. 2014 16 5184. doi: 10.1021/ol502541w
[78]	Nakamura I. Onuma T. Zhang D. Terada M. Tetrahedron Lett. 2014 55 1178. doi: 10.1016/j.tetlet.2013.12.105
[79]	Hazra S. Mondal B. Rahaman H. Roy B. Eur. J. Org. Chem. 2014 2806.
[80]	Zhou S. Yang Z. Chen X. Li Y. Zhang L. Fang H. Wang W. Zhu X. Wang S. J. Org. Chem. 2015 80 6323. doi: 10.1021/acs.joc.5b00767
[81]	Sakae R. Hirano k. Satoh T. Miura M. Angew. Chem. Int. Ed. 2015 54 613.
[82]	Sakae R. Hirano K. Miura M. J. Am. Chem. Soc. 2015 137 6460. doi: 10.1021/jacs.5b02775
[83]	Hemric B. N. Shen K. Wang Q. J. Am. Chem. Soc. 2016 138 5813. doi: 10.1021/jacs.6b02840
[84]	Nakamura I. Jo T. Ishida Y. Tashiro H. Terada M. Org. Lett. 2017 19 3059. doi: 10.1021/acs.orglett.7b01110
[85]	Xu Q.-F. Liu Q.-Q. Zhang X. You S.-L. Angew. Chem. Int. Ed. 2018 57 15204. doi: 10.1002/anie.201809003
[86]	Ichikawa S. Zhu S. Buchwald S. L. Angew. Chem. Int. Ed. 2018 57 8714. doi: 10.1002/anie.201803026
[87]	Ishida Y. Nakamura I. Terada M. J. Am. Chem. Soc. 2018 140 8629. doi: 10.1021/jacs.8b03669
[88]	Wu F. Zhang M. Zhou W. Chen W. Liu M. Wu H. J. Org. Chem. 2018 83 5999. doi: 10.1021/acs.joc.8b00605
[89]	Yang Z. Jiang K. Chen Y.-C. Wei Y. J. Org. Chem. 2019 84 3725. doi: 10.1021/acs.joc.9b00262
[90]	Wang Q. Li X. Org. Lett. 2016 18 2102. doi: 10.1021/acs.orglett.6b00727
[91]	Śnieżek M. Stecko S. Panfil I. Furman B. Chmielewski M. J. Org. Chem. 2013 78 7048. doi: 10.1021/jo400807c
[92]	Diethelm S. Carreira E. M. J. Am. Chem. Soc. 2015 137 6084. doi: 10.1021/jacs.5b02574
[93]	Wang F.-X. Du J.-Y. Wang H.-B. Zhang P.-L. Zhang G.-B. Yu K.-Y. Zhang X.-Z. An X.-T. Cao Y.-X. Fan C.-A. J. Am. Chem. Soc. 2017 139 4282. doi: 10.1021/jacs.6b13401
[94]	Nomura T. Yojoshima T. Fukuyama T. Org. Lett. 2018 20 119. doi: 10.1021/acs.orglett.7b03555