Condensation-Based Methods for the C–H Bond Functionalization of Amines

Abstract

This review aims to provide a comprehensive overview of condensation-based methods for the C–H bond functionalization of amines that feature azomethine ylides as key intermediates. These transformations are typically redox-neutral and share common attributes with classic name reactions such as the Strecker, Mannich, ­Friedel–Crafts, Pictet–Spengler, and Kabachnik–Fields reactions, while incorporating a redox-isomerization step. This approach provides an ideal platform to rapidly transform simple starting materials into complex amines.

1 Introduction

1.1 General Remarks

1.2 Overview

1.3 Scope of This Review

2 Aromatization of Cyclic Amines

2.1 Pyridines from Piperidine

2.2 Isoquinolines from Tetrahydroisoquinolines and Quinolines from Tetrahydroquinolines

2.3 Pyrroles from 3-Pyrroline or Pyrrolidine

2.4 Indoles from Indolines

3 Pericyclic Reactions

3.1 (3+2)-Dipolar Cycloadditions

3.2 6π-Electrocyclizations

3.3 1,5-Proton Shifts

4 Redox-Variants of Classic Transformations Incorporating a C–H Bond Functionalization Step

4.1 α-Cyanation

4.2 α-Alkynylation

4.3 α-Phosphonation

4.4 α-Arylation

4.5 α-Alkylation with Ketones

4.6 Redox-Ugi Reaction

4.7 Miscellaneous Intermolecular Reactions

5 Redox-Annulations

6 Reactions Involving β-C–H Bond Functionalization

7 Outlook

Key words

C–H bond functionalization - amines - heterocycles - redox-neutral - redox-isomerization - condensation

Publication History

Received: 08 July 2021

Accepted after revision: 02 September 2021

Accepted Manuscript online:
02 September 2021

Article published online:
12 October 2021

• References

• 1a Taylor RD, MacCoss M, Lawson AD. G. J. Med. Chem. 2014; 57: 5845
• 1b Vitaku E, Smith DT, Njardarson JT. J. Med. Chem. 2014; 57: 10257
• 1c Blakemore DC, Castro L, Churcher I, Rees DC, Thomas AW, Wilson DM, Wood A. Nat. Chem. 2018; 10: 383

For a general overview on amine C–H bond functionalization, see:
• 2a Dutta S, Li B, Rickertsen DR. L, Valles DA, Seidel D. SynOpen 2021; 5: 173

Other selected reviews:
• 2b Campos KR. Chem. Soc. Rev. 2007; 36: 1069
• 2c Jazzar R, Hitce J, Renaudat A, Sofack-Kreutzer J, Baudoin O. Chem. Eur. J. 2010; 16: 2654
• 2d Yeung CS, Dong VM. Chem. Rev. 2011; 111: 1215
• 2e Mitchell EA, Peschiulli A, Lefevre N, Meerpoel L, Maes BU. W. Chem. Eur. J. 2012; 18: 10092
• 2f Jones KM, Klussmann M. Synlett 2012; 23: 159
• 2g Peng B, Maulide N. Chem. Eur. J. 2013; 19: 13274
• 2h Girard SA, Knauber T, Li C.-J. Angew. Chem. Int. Ed. 2014; 53: 74
• 2i Haibach MC, Seidel D. Angew. Chem. Int. Ed. 2014; 53: 5010
• 2j Wang L, Xiao J. Adv. Synth. Catal. 2014; 356: 1137
• 2k Vo C.-VT, Bode JW. J. Org. Chem. 2014; 79: 2809
• 2l Qin Y, Lv J, Luo S. Tetrahedron Lett. 2014; 55: 551
• 2m Beatty JW, Stephenson CR. J. Acc. Chem. Res. 2015; 48: 1474
• 2n Qin Y, Zhu L, Luo S. Chem. Rev. 2017; 117: 9433
• 2o Cheng M.-X, Yang S.-D. Synlett 2017; 28: 159
• 2p Chu JC. K, Rovis T. Angew. Chem. Int. Ed. 2018; 57: 62
• 2q Stateman LM, Nakafuku KM, Nagib DA. Synthesis 2018; 50: 1569
• 2r Edwards PM, Schafer LL. Chem. Commun. 2018; 54: 12543
• 2s Gonnard L, Guérinot A, Cossy J. Tetrahedron 2019; 75: 145
• 2t Liu S, Zhao Z, Wang Y. Chem. Eur. J. 2019; 25: 2423
• 2u Antermite D, Bull JA. Synthesis 2019; 51: 3171
• 2v Zhang T, Wu Y.-H, Wang N.-X, Xing Y. Synthesis 2019; 51: 4531
• 2w Trowbridge A, Walton SM, Gaunt MJ. Chem. Rev. 2020; 120: 2613
• 2x Kapoor M, Singh A, Sharma K, Hua Hsu M. Adv. Synth. Catal. 2020; 362: 4513
• 2y An X.-D, Xiao J. Org. Chem. Front. 2021; 8: 1364
• 2z Basak S, Winfrey L, Kustiana BA, Melen RL, Morrill LC, Pulis AP. Chem. Soc. Rev. 2021; 50: 3720
• 2aa Caplin MJ, Foley DJ. Chem. Sci. 2021; 12: 4646
• 2ab Ohno S, Miyoshi M, Murai K, Arisawa M. Synthesis 2021; in press, DOI:

Selected reviews on various types of redox-neutral transformations:
• 3a Burns NZ, Baran PS, Hoffmann RW. Angew. Chem. Int. Ed. 2009; 48: 2854
• 3b Mahatthananchai J, Bode JW. Acc. Chem. Res. 2014; 47: 696
• 3c Ketcham JM, Shin I, Montgomery TP, Krische MJ. Angew. Chem. Int. Ed. 2014; 53: 9142
• 3d Huang H, Ji X, Wu W, Jiang H. Chem. Soc. Rev. 2015; 44: 1155

Selected reviews on the chemistry of azomethine ylides:
• 4a 1,3-Dipolar Cycloaddition Chemistry, Vol. 1. Padwa A. John Wiley & Sons; New York: 1984
• 4b 1,3-Dipolar Cycloaddition Chemistry, Vol. 2. Padwa A. John Wiley & Sons; New York: 1984
• 4c Synthetic Applications of 1,3-Dipolar Cycloaddition Chemistry. Towards Heterocycles and Natural Products. In Chemistry of Heterocyclic Compounds, Vol. 59. Padwa A, Pearson WH. John Wiley & Sons; New York: 2002
• 4d Najera C, Sansano JM. Curr. Org. Chem. 2003; 7: 1105
• 4e Coldham I, Hufton R. Chem. Rev. 2005; 105: 2765
• 4f Pandey G, Banerjee P, Gadre SR. Chem. Rev. 2006; 106: 4484
• 4g Pinho e Melo TM. V. D. Eur. J. Org. Chem. 2006; 2873
• 4h Bonin M, Chauveau A, Micouin L. Synlett 2006; 2349
• 4i Nair V, Suja TD. Tetrahedron 2007; 63: 12247
• 4j Najera C, Sansano JM. Top. Heterocycl. Chem. 2008; 12: 117
• 4k Stanley LM, Sibi MP. Chem. Rev. 2008; 108: 2887
• 4l Nyerges M, Toth J, Groundwater PW. Synlett 2008; 1269
• 4m Pineiro M, Pinho e Melo TM. V. D. Eur. J. Org. Chem. 2009; 5287
• 4n Burrell AJ. M, Coldham I. Curr. Org. Synth. 2010; 7: 312
• 4o Anac O, Gungor FS. Tetrahedron 2010; 66: 5931
• 4p Adrio J, Carretero JC. Chem. Commun. 2011; 47: 6784
• 4q Adrio J, Carretero JC. Chem. Commun. 2014; 50: 12434
• 4r Hashimoto T, Maruoka K. Chem. Rev. 2015; 115: 5366
• 4s Meyer A, Ryan J. Molecules 2016; 21: 935
• 4t Otero-Fraga J, Montesinos-Magraner M, Mendoza A. Synthesis 2017; 49: 802
• 4u Döndas HA, de Gracia Retamosa M, Sansano JM. Synthesis 2017; 49: 2819
• 4v Tang S, Zhang X, Sun J, Niu D, Chruma JJ. Chem. Rev. 2018; 118: 10393
• 4w Wei L, Chang X, Wang C.-J. Acc. Chem. Res. 2020; 53: 1084
• 5 Seidel D. Acc. Chem. Res. 2015; 48: 317
• 6 Mahato S, Jana CK. Chem. Rec. 2016; 16: 1477

Examples of hydride transfer-based methods involving a condensation step:
• 7a Zhang C, Murarka S, Seidel D. J. Org. Chem. 2009; 74: 419
• 7b Mori K, Ohshima Y, Ehara K, Akiyama T. Chem. Lett. 2009; 38: 524
• 7c Haibach MC, Deb I, De C K, Seidel D. J. Am. Chem. Soc. 2011; 133: 2100
• 7d Bai G, Dong F, Xu L, Liu Y, Wang L, Li S.-S. Org. Lett. 2019; 21: 6225
• 7e Wang S, Shen Y.-B, Li L.-F, Qiu B, Yu L, Liu Q, Xiao J. Org. Lett. 2019; 21: 8904

For a review, see:
• 8a Rahman M, Mukherjee A, Kovalev IS, Kopchuk DS, Zyryanov GV, Tsurkan MV, Majee A, Ranu BC, Charushin VN, Chupakhin ON, Santra S. Adv. Synth. Catal. 2019; 361: 2161

Selected examples:
• 8b Cohen N, Blount JF, Lopresti RJ, Trullinger DP. J. Org. Chem. 1979; 44: 4005
• 8c Bi H.-P, Zhao L, Liang Y.-M, Li C.-J. Angew. Chem. Int. Ed. 2009; 48: 792
• 8d Zhang C, Seidel D. J. Am. Chem. Soc. 2010; 132: 1798
• 8e Bi H.-P, Teng Q, Guan M, Chen W.-W, Liang Y.-M, Yao X, Li C.-J. J. Org. Chem. 2010; 75: 783
• 8f Das D, Richers MT, Ma L, Seidel D. Org. Lett. 2011; 13: 6584
• 8g Dighe SU, Kumar KS. A, Srivastava S, Shukla P, Singh S, Dikshit M, Batra S. J. Org. Chem. 2015; 80: 99
• 8h Kang Y, Seidel D. Org. Lett. 2016; 18: 4277
• 9a Rügheimer L. Ber. Dtsch. Chem. Ges. 1891; 24: 2186
• 9b Rügheimer L. Ber. Dtsch. Chem. Ges. 1892; 25: 2421
• 10 Skraup S, Böhm K. Ber. Dtsch. Chem. Ges. 1926; 59: 1015
• 11 Parker ED, Furst A. J. Org. Chem. 1958; 23: 201
• 12 Poirier RH, Morin RD, McKim AM, Bearse AE. J. Org. Chem. 1961; 26: 4275
• 13 Burrows EP, Hutton RF, Burrows WD. J. Org. Chem. 1962; 27: 316
• 14 Burrows WD, Burrows EP. J. Org. Chem. 1963; 28: 1180
• 15 Kameswari U, Pillai CN. Catal. Lett. 1996; 38: 53
• 16 Moura NM. M, Núñez C, Santos SM, Faustino MA. F, Cavaleiro JA. S, Paz FA. A, Neves MG. P. M. S, Capelo JL, Lodeiro C. Chem. Eur. J. 2014; 20: 6684
• 17 Platonova AY, Seidel D. Tetrahedron Lett. 2015; 56: 3147
• 18 Chang M.-Y, Tsai Y.-L. J. Org. Chem. 2020; 85: 5651
• 19 Sainsbury M, Dyke SF, Brown DW, Lugton WG. D. Tetrahedron 1968; 24: 427
• 20 Dannhardt G, Mayer KK, Obergrusberger I, Roelcke J. Arch. Pharm. 1986; 319: 977
• 21 Dannhardt G, Roelcke J. Arch. Pharm. 1992; 325: 671
• 22 Lee Y, Huang H, Sayre LM. J. Am. Chem. Soc. 1996; 118: 7241
• 23 Cook AG, Switek KA, Cutler KA, Witt AM. Lett. Org. Chem. 2004; 1: 1
• 24 Oda M, Fukuchi Y, Ito S, Thanh NC, Kuroda S. Tetrahedron Lett. 2007; 48: 9159
• 25 Poláčková V, Veverková E, Toma S, Bogdal D. Synth. Commun. 2009; 39: 1871
• 26 Pahadi NK, Paley M, Jana R, Waetzig SR, Tunge JA. J. Am. Chem. Soc. 2009; 131: 16626
• 27 Xue X, Yu A, Cai Y, Cheng J.-P. Org. Lett. 2011; 13: 6054
• 28 Mao H, Xu R, Wan J, Jiang Z, Sun C, Pan Y. Chem. Eur. J. 2010; 16: 13352
• 29 Deb I, Das D, Seidel D. Org. Lett. 2011; 13: 812
• 30 Bayindir S, Erdogan E, Kilic H, Aydin O, Saracoglu N. J. Heterocycl. Chem. 2015; 52: 1589
• 31 Aydin O, Kilic H, Bayindir S, Erdogan E, Saracoglu N. J. Heterocycl. Chem. 2015; 52: 1540
• 32 Ramakumar K, Tunge JA. Chem. Commun. 2014; 50: 13056
• 33 Ardill H, Grigg R, Sridharan V, Surendrakumar S, Thianpatanagul S, Kanajun S. J. Chem. Soc., Chem. Commun. 1986; 602
• 34 Ardill H, Dorrity MJ. R, Grigg R, Leon-Ling M.-S, Malone JF, Sridharan V, Thianpatanagul S. Tetrahedron 1990; 46: 6433
• 35 Ardill H, Fontaine XL. R, Grigg R, Henderson D, Montgomery J, Sridharan V, Surendrakumar S. Tetrahedron 1990; 46: 6449
• 36 Wittland C, Arend M, Risch N. Synthesis 1996; 367
• 37 Xie H, Xiang J, Dang Q, Bai X. Synlett 2012; 23: 585
• 38 Mantelingu K, Lin Y, Seidel D. Org. Lett. 2014; 16: 5910
• 39 Sutariya TR, Labana BM, Parmar NJ, Kant R, Gupta VK, Plata GB, Padrón JM. New J. Chem. 2015; 39: 2657
• 40 Kumar CS. P, Harsha KB, Sandhya NC, Ramesha AB, Mantelingu K, Rangappa KS. New J. Chem. 2015; 39: 8397
• 41 Strada A, Fredditori M, Zanoni G, Protti S. Molecules 2019; 24: 1318
• 42 Tolbert LM, Haubrich JE. J. Am. Chem. Soc. 1994; 116: 10593
• 43 Rahman M, Bagdi AK, Mishra S, Hajra A. Chem. Commun. 2014; 50: 2951
• 44 Kumar CS. P, Harsha KB, Mantelingu K, Rangappa KS. RSC Adv. 2015; 5: 61664
• 45 Wu X, Zhu Z.-H, He H, Ren L, Zhu C.-F, Li Y.-G. J. Org. Chem. 2020; 85: 6216
• 46 Zhang X, Liu M, Qiu W, Evans J, Kaur M, Jasinski JP, Zhang W. ACS Sustainable Chem. Eng. 2018; 6: 5574
• 47 Guo J, Zhao Y, Fang D, Wang Q, Bu Z. Org. Biomol. Chem. 2018; 16: 6025
• 48 Huang Y, Huang Y.-X, Sun J, Yan C.-G. RSC Adv. 2018; 8: 23990
• 49 Boudriga S, Haddad S, Askri M, Soldera A, Knorr M, Strohmann C, Golz C. RSC Adv. 2019; 9: 11082
• 50 Safaei-Ghomi J, Masoomi R. RSC Adv. 2015; 5: 15591
• 51 Yang H.-T, Tan Y.-C, Ge J, Wu H, Li J.-X, Yang Y, Sun X.-Q, Miao C.-B. J. Org. Chem. 2016; 81: 11201
• 52 Shi J.-L, Zhang X.-F, Wang H.-J, Li F.-B, Zhong X.-X, Liu C.-X, Liu L, Liu C.-Y, Qin H.-M, Huang Y.-S. J. Org. Chem. 2016; 81: 7662
• 53 Zheng K, Zhuang S, You M, Shu W, Wu A, Wu Y. ChemistrySelect 2017; 2: 10762
• 54 Zheng K.-L, You M.-Q, Shu W.-M, Wu Y.-D, Wu A.-X. Org. Lett. 2017; 19: 2262
• 55 Grigg R, Gunaratne HQ. N, Henderson D, Sridharan V. Tetrahedron 1990; 46: 1599
• 56a Soeder RW, Bowers K, Pegram LD, Cartaya-Marin CP. Synth. Commun. 1992; 22: 2737
• 56b Deb I, Seidel D. Tetrahedron Lett. 2010; 51: 2945
• 57 Kang Y, Richers MT, Sawicki CH, Seidel D. Chem. Commun. 2015; 51: 10648
• 58 Yang Z, Lu N, Wei Z, Cao J, Liang D, Duan H, Lin Y. J. Org. Chem. 2016; 81: 11950
• 59 Xia P.-J, Sun Y.-H, Xiao J.-A, Zhou Z.-F, Wen S.-S, Xiong Y, Ou G.-C, Chen X.-Q, Yang H. J. Org. Chem. 2015; 80: 11573
• 60 Mure M, Mills SA, Klinman JP. Biochemistry 2002; 41: 9269
• 61 Mure M. Acc. Chem. Res. 2004; 37: 131
• 62 Largeron M, Fleury M.-B. Science 2013; 339: 43
• 63 Wendlandt AE, Stahl SS. Angew. Chem. Int. Ed. 2015; 54: 14638
• 64 Largeron M. Org. Biomol. Chem. 2017; 15: 4722
• 65 Cheng Y.-F, Rong H.-J, Yi C.-B, Yao J.-J, Qu J. Org. Lett. 2015; 17: 4758
• 66 Rong H.-J, Cheng Y.-F, Liu F.-F, Ren S.-J, Qu J. J. Org. Chem. 2017; 82: 532
• 67 Vasu D, Fuentes de Arriba ÁL, Leitch JA, de Gombert A, Dixon DJ. Chem. Sci. 2019; 10: 3401
• 68 Vasu D, Leitch JA, Dixon DJ. Tetrahedron 2019; 75: 130726
• 69 Ma L, Chen W, Seidel D. J. Am. Chem. Soc. 2012; 134: 15305
• 70 Murahashi S.-I, Komiya N, Terai H, Nakae T. J. Am. Chem. Soc. 2003; 125: 15312
• 71 Das D, Sun AX, Seidel D. Angew. Chem. Int. Ed. 2013; 52: 3765
• 72 Seidel D. Org. Chem. Front. 2014; 1: 426
• 73 Zheng Q, Meng W, Jiang G, Yu Z. Org. Lett. 2013; 15: 5928
• 74 Lin W, Cao T, Fan W, Han Y, Kuang J, Luo H, Miao B, Tang X, Yu Q, Yuan W, Zhang J, Zhu C, Ma S. Angew. Chem. Int. Ed. 2014; 53: 277
• 75 Lin W, Ma S. Org. Chem. Front. 2014; 1: 338
• 76 Lin W, Ma S. Org. Chem. Front. 2017; 4: 958
• 77 Zhou S, Tong R. Chem. Eur. J. 2016; 22: 7084
• 78 Zhou S, Tong R. Org. Lett. 2017; 19: 1594
• 79 Yu J, Zhang Z, Zhou S, Zhang W, Tong R. Org. Chem. Front. 2018; 5: 242
• 80 Li J, Wang H, Sun J, Yang Y, Liu L. Org. Biomol. Chem. 2014; 12: 2523
• 81 Shao G, He Y, Xu Y, Chen J, Yu H, Cao R. Eur. J. Org. Chem. 2015; 4615
• 82 Villamizar MC. O, Galvis CE. P, Kouznetsov VV. Synthesis 2021; 53: 547
• 83 Zhao H, He W, Wei L, Cai M. Catal. Sci. Technol. 2016; 6: 1488
• 84 Gulati U, Rawat S, Rajesh UC, Rawat DS. New J. Chem. 2017; 41: 8341
• 85 Xu H, Wang J, Wang P, Niu X, Luo Y, Zhu L, Yao X. RSC Adv. 2018; 8: 32942
• 86 Shi L, Wang M, Pan L, Li Y, Liu Q. Chem. Commun. 2018; 54: 8721
• 87 Das D, Seidel D. Org. Lett. 2013; 15: 4358
• 88 Hu G, Chen W, Ma D, Zhang Y, Xu P, Gao Y, Zhao Y. J. Org. Chem. 2016; 81: 1704
• 89 Chen W, Wilde RG, Seidel D. Org. Lett. 2014; 16: 730
• 90 Haldar S, Mahato S, Jana CK. Asian J. Org. Chem. 2014; 3: 44
• 91 Haldar S, Roy SK, Maity B, Koley D, Jana CK. Chem. Eur. J. 2015; 21: 15290
• 92 Haldar S, Jana CK. Org. Biomol. Chem. 2019; 17: 1800
• 93 Yi F, Su J, Zhang S, Yi W, Zhang L. Eur. J. Org. Chem. 2015; 7360
• 94 Zhang Q, Lv J, Luo S. Acta Chim. Sin. 2016; 74: 61
• 95 Rahman I, Deka B, Thakuria R, Deb ML, Baruah PK. Org. Biomol. Chem. 2020; 18: 6514
• 96a Gulati U, Rawat S, Rawat DS. Tetrahedron Lett. 2020; 61: 152304
• 96b Kaur P, Gurjar KK, Kumar V, Gohit S, Gupta V, Kumar R. ChemistrySelect 2020; 5: 12514
• 97 Chen W, Seidel D. Org. Lett. 2014; 16: 3158
• 98 Zhu Z, Seidel D. Org. Lett. 2016; 18: 631
• 99 Yan J, Bai Q, Xu C, Feng G. Synthesis 2016; 48: 3730
• 100 Haldar S, Saha S, Mandal S, Jana CK. Green Chem. 2018; 20: 3463
• 101 Huang J, Li L, Xiao T, Mao Z, Zhou L. Asian J. Org. Chem. 2016; 5: 1204
• 102 Yi C.-B, She Z.-Y, Cheng Y.-F, Qu J. Org. Lett. 2018; 20: 668
• 103 Purkait A, Jana CK. Synthesis 2019; 51: 2687
• 104 Jiang D, Wu Z, Wang J. Chin. J. Chem. 2020; 38: 135
• 105 Zhang C, De CK, Mal R, Seidel D. J. Am. Chem. Soc. 2008; 130: 416
• 106 Richers MT, Deb I, Platonova AY, Zhang C, Seidel D. Synthesis 2013; 45: 1730
• 107 Dieckmann A, Richers MT, Platonova AY, Zhang C, Seidel D, Houk KN. J. Org. Chem. 2013; 78: 4132
• 108 Richers MT, Zhao C, Seidel D. Beilstein J. Org. Chem. 2013; 9: 1194
• 109 Zheng L, Yang F, Dang Q, Bai X. Org. Lett. 2008; 10: 889
• 110 Afanasyev OI, Podyacheva E, Rudenko A, Tsygankov AA, Makarova M, Chusov D. J. Org. Chem. 2020; 85: 9347
• 111 Deb ML, Borpatra PJ, Baruah PK. Green Chem. 2019; 21: 69
• 112 Richers MT, Breugst M, Platonova AY, Ullrich A, Dieckmann A, Houk KN, Seidel D. J. Am. Chem. Soc. 2014; 136: 6123
• 113 Jarvis CL, Richers MT, Breugst M, Houk KN, Seidel D. Org. Lett. 2014; 16: 3556
• 114 Kirkeby EK, Roberts AG. Chem. Commun. 2020; 56: 9118
• 115 Mahato S, Haque MA, Dwari S, Jana CK. RSC Adv. 2014; 4: 46214
• 116 Zhang C, Das D, Seidel D. Chem. Sci. 2011; 2: 233
• 117 Ma L, Seidel D. Chem. Eur. J. 2015; 21: 12908
• 118 Paul A, Chandak HS, Ma L, Seidel D. Org. Lett. 2020; 22: 976
• 119 Rickertsen DR. L, Ma L, Paul A, Abboud KA, Seidel D. SynOpen 2020; 4: 123
• 120 Kang Y, Chen W, Breugst M, Seidel D. J. Org. Chem. 2015; 80: 9628
• 121 Chen W, Seidel D. Org. Lett. 2016; 18: 1024
• 122 Openshaw HT, Whittaker NJ. J. Chem. Soc. 1963; 1461
• 123 Li J, Qin C, Yu Y, Fan H, Fu Y, Li H, Wang W. Adv. Synth. Catal. 2017; 359: 2191
• 124 Li J, Fu Y, Qin C, Yu Y, Li H, Wang W. Org. Biomol. Chem. 2017; 15: 6474
• 125 Zhu Z, Seidel D. Org. Lett. 2017; 19: 2841
• 126 Paul A, Adili A, Seidel D. Org. Lett. 2019; 21: 1845
• 127 Zhu Z, Lv X, Anesini JE, Seidel D. Org. Lett. 2017; 19: 6424
• 128 Liu Y, Wu J, Jin Z, Jiang H. Synlett 2018; 29: 1061
• 129 Zhu Z, Chandak HS, Seidel D. Org. Lett. 2018; 20: 4090
• 130 Chen W, Kang Y, Wilde RG, Seidel D. Angew. Chem. Int. Ed. 2014; 53: 5179
• 131 Mukhopadhyay C, Rana S, Butcher RJ. Synth. Commun. 2012; 42: 3077
• 132 Ma L, Paul A, Breugst M, Seidel D. Chem. Eur. J. 2016; 22: 18179
• 133 Huang Y, Fang H.-L, Huang Y.-X, Sun J, Yan C.-G. J. Org. Chem. 2019; 84: 12437
• 134 Fang H.-L, Han Y, Sun J, Yan C.-G. ChemistrySelect 2020; 5: 14086
• 135 Zheng K.-L, Shu W.-M, Ma J.-R, Wu Y.-D, Wu A.-X. Org. Lett. 2016; 18: 3526
• 136 Du Y, Yu A, Jia J, Zhang Y, Meng X. Chem. Commun. 2017; 53: 1684
• 137 Mandal S, Dwari S, Jana CK. J. Org. Chem. 2018; 83: 8874
• 138 Chang M.-Y, Wu Y.-S. J. Org. Chem. 2019; 84: 3638
• 139 Roy SK, Purkait A, Aziz SM. T, Jana CK. Chem. Commun. 2020; 56: 3167
• 140 Mandal S, Mahato S, Jana CK. Org. Lett. 2015; 17: 3762