Recent Developments in the Synthesis of Imidazo[1,2-a]pyridines

Abstract

Advances in the last decade for the synthesis of the imidazo[1,2-a]pyridine scaffold from various substrates employing approaches such as multicomponent reactions, tandem processes, rearrangement reactions, inter- and intramolecular oxidative/reductive cyclizations, and transition-metal-catalyzed C–H activation are summarized in this review. The mechanisms for the selected transformations are also discussed.

1 Introduction

2 From 2-Aminopyridines

2.1 Revisiting Traditional Cyclocondensation

2.1.1 Regioselectivity in Cyclocondensation

2.2 Reactions of Carbonyl Compounds

2.3 Reactions of α,β-Unsaturated Carbonyl Compounds

2.4 Reactions of Nitroolefins

2.5 Reactions of Alkynes

2.6 Multicomponent Reactions

2.6.1 Three-Component Reaction of Aldehyde, 2-Aminopyridine, and Isocyanide

2.6.2 Three-Component Reaction of 2-Aminopyridine, Aldehyde, and Alkyne

2.6.3 Other Multicomponent Procedures

2.7 Reactions of N-Substituted 2-Aminopyridines

2.8 Miscellaneous Reactions

3 From Pyridines

3.1 Multicomponent Reactions

4 From Pyridinium Salts

5 From Imidazoles

5.1 Reactions of Heterocyclic Ketene Aminals

6 Miscellaneous Methods

7 Conclusion

Key words

imidazo[1,2-a]pyridine - 2-aminopyridine - tandem reaction - multicomponent reaction - C–H activation

• References

• 1a Wan J, Zheng C.-J, Fung M.-K, Liu X.-K, Lee C.-S, Zhang X.-H. J. Mater. Chem. 2012; 22: 4502
• 1b Song G, Zhang Y, Li X. Organometallics 2008; 27: 1936
• 1c John A, Shaikh MM, Ghosh P. Dalton Trans. 2009; 10581
• 1d Enguehard-Gueiffier C, Gueiffier A. Mini-Rev. Med. Chem. 2007; 7: 888
• 2a Couty F, Evano G. Bicyclic 5-6 Systems with One Bridgehead Nitrogen Atom: One Extra Heteroatom . In Comprehensive Heterocyclic Chemistry III . Katritzky AR, Ramsden CA, Scriven EF. V, Taylor RJ. K. Elsevier; Oxford: 2008: 409
• 2b Fisher MH, Lusi A. J. Med. Chem. 1972; 15: 982
• 2c Gudmundsson KS, Williams JD, Drach JC, Townsend LB. J. Med. Chem. 2003; 46: 1449
• 2d Gudmundsson KS, Johns BA. Org. Lett. 2003; 5: 1369
• 2e Ismail MA, Brun R, Wenzler T, Tanious FA, Wilson WD, Boykin DW. J. Med. Chem. 2004; 47: 3658
• 2f Kaminski JJ, Bristol JA, Puchalski C, Lovey RG, Elliott AJ, Guzik H, Solomon DM, Conn DJ, Domalski MS. J. Med. Chem. 1985; 28: 876
• 2g Ulloora S, Shabaraya R, Adhikari AV. Bioorg. Med. Chem. Lett. 2013; 23: 3368
• 2h Hieke M, Rödl CB, Wisniewska JM, la Buscató E, Stark H, Schubert-Zsilavecz M, Steinhilber D, Hofmann B, Proschak E. Bioorg. Med. Chem. Lett. 2012; 22: 1969
• 2i Cheng Y, Moraski GC, Cramer J, Miller MJ, Schorey JS. PLoS ONE 2014; 9: e87483
• 3a Byth KF, Culshaw JD, Green S, Oakes SE, Thomas AP. Bioorg. Med. Chem. Lett. 2004; 14: 2245
• 3b Kishino H, Moriya M, Sakuraba S, Sakamoto T, Takahashi H, Suzuki T, Moriya R, Ito M, Iwaasa H, Takenaga N, Ishihara A, Kanatani A, Sato N, Fukami T. Bioorg. Med. Chem. Lett. 2009; 19: 4589
• 3c Warshakoon NC, Wu S, Boyer A, Kawamoto R, Sheville J, Renock S, Xu K, Pokross M, Evdokimov AG, Walter R, Mekel M. Bioorg. Med. Chem. Lett. 2006; 16: 5598
• 3d Zhuang Z.-P, Kung M.-P, Wilson A, Lee C.-W, Plössl K, Hou C, Holtzman DM, Kung HF. J. Med. Chem. 2003; 46: 237
• 4a Suloeva E, Yure M, Gudriniece E. Chem. Heterocycl. Compd. 1999; 35: 1121
• 4b Sulojeva E, Yure M, Gudriniece E. Chem. Heterocycl. Compd. 2000; 36: 885
• 5 Koubachi J, El Kazzouli S, Bousmina M, Guillaumet G. Eur. J. Org. Chem. 2014; 5119
• 6 A review on synthesis of imidazo[1,2-a]pyridine appeared after submission of our manuscript: Bagdi AK, Santra S, Monir K, Hajra A. Chem. Commun. 2015; 51: 1555
• 7 Tschitschibabin AE. Chem. Ber. 1925; 58: 1704
• 8a Cai L, Brouwer C, Sinclair K, Cuevas J, Pike VW. Synthesis 2006; 133
• 8b Xie Y.-Y, Chen Z.-C, Zheng Q.-G. J. Chem. Res. 2003; 614
• 8c Chunavala KC, Joshi G, Suresh E, Adimurthy S. Synthesis 2011; 635
• 8d Adib M, Mohamadi A, Sheikhi E, Ansari S, Bijanzadeh HR. Synlett 2010; 1606
• 9a Xie Y.-Y, Chen Z.-C, Zheng Q.-G. Synthesis 2002; 1505
• 9b Kumbhar VV, Hangirgekar SP, Wadwale NB. Der Pharma Chemica 2013; 5: 274
• 10 Yadav JS, Subba Reddy BV, Gopal Rao Y, Srinivas M, Narsaiah AV. Tetrahedron Lett. 2007; 48: 7717
• 11 Le Z.-G, Xie Z.-B, Xu J.-P. Molecules 2012; 17: 13368 ; http://www.mdpi.com/journal/molecules
• 12 Huang H.-Y, Hou R.-S, Wang H.-M, Chen L.-C. J. Chin. Chem. Soc. 2004; 51: 1377
• 13a Guetzoyan L, Nikbin N, Baxendale IR, Ley SV. Chem. Sci. 2013; 4: 764
• 13b Herath A, Dahl R, Cosford ND. P. Org. Lett. 2010; 12: 412
• 14 Donohoe TJ, Kabeshov MA, Rathi AH, Smith IE. D. Org. Biomol. Chem. 2012; 10: 1093
• 15 Ueno M, Nabana T, Togo H. J. Org. Chem. 2003; 68: 6424
• 16 Chang Y.-L, Wang H.-M, Hou R.-S, Kang I.-J, Chen L.-C. J. Chin. Chem. Soc. 2010; 57: 153
• 17 Wang X, Ma L, Yu W. Synthesis 2011; 2445
• 18 Ma L, Wang X, Yu W, Han B. Chem. Commun. 2011; 47: 11333
• 19 Stasyuk AJ, Banasiewicz M, Cyrański MK, Gryko DT. J. Org. Chem. 2012; 77: 5552
• 20 Fei Z, Zhu Y.-p, Liu M.-c, Jia F.-c, Wu A.-x. Tetrahedron Lett. 2013; 54: 1222
• 21 Koubachi J, El Kazzouli S, Berteina-Raboin S, Mouaddib A, Guillaumet G. J. Org. Chem. 2007; 72: 7650
• 22 Hiebel M.-A, Fall Y, Scherrmann M.-C, Berteina-Raboin S. Eur. J. Org. Chem. 2014; 4643
• 23 DiMauro EF, Vitullo JR. J. Org. Chem. 2006; 71: 3959
• 24 Wang Y, Frett B, Li H.-y. Org. Lett. 2014; 16: 3016
• 25a Marhadour S, Bazin M.-A, Marchand P. Tetrahedron Lett. 2012; 53: 297
• 25b Marhadour S, Marchand P, Pagniez F, Bazin M.-A, Picot C, Lozach O, Ruchaud S, Antoine M, Meijer L, Rachidi N, Le Pape P. Eur. J. Med. Chem. 2012; 58: 543
• 26 Bangade VM, Reddy BC, Thakur PB, Madhu Babu B, Meshram HM. Tetrahedron Lett. 2013; 54: 4767
• 27 Kurteva VB, Lubenov LA, Nedeltcheva DV, Nikolova RP, Shivachev BL. ARKIVOC 2012; (viii): 282
• 28 Kurteva VB, Lubenov LA, Antonova DV. RSC Adv. 2014; 4: 175
• 29 Bagdi AK, Rahman M, Santra S, Majee A, Hajra A. Adv. Synth. Catal. 2013; 355: 1741
• 30 Chandra Mohan D, Reddy Donthiri R, Nageswara Rao S, Adimurthy S. Adv. Synth. Catal. 2013; 355: 2217
• 31 Cai Z.-J, Wang S.-Y, Ji S.-J. Adv. Synth. Catal. 2013; 355: 2686
• 32 Pericherla K, Jha A, Khungar B, Kumar A. Org. Lett. 2013; 15: 4304
• 33 Zhang Y, Chen Z, Wu W, Zhang Y, Su W. J. Org. Chem. 2013; 78: 12494
• 34 Albrecht L, Albrecht A, Ransborg LK, Jorgensen KA. Chem. Sci. 2011; 2: 1273
• 35 Monir K, Kumar Bagdi A, Mishra S, Majee A, Hajra A. Adv. Synth. Catal. 2014; 356: 1105
• 36 Kaswan P, Pericherla K, Rajnikant, Kumar A. Tetrahedron 2014; 70: 8539
• 37 Yan H, Yang S, Gao X, Zhou K, Ma C, Yan R, Huang G. Synlett 2012; 23: 2961
• 38 Santra S, Bagdi AK, Majee A, Hajra A. Adv. Synth. Catal. 2013; 355: 1065
• 39 Santra S, Mitra S, Bagdi AK, Majee A, Hajra A. Tetrahedron Lett. 2014; 55: 5151
• 40 Yan H, Wang Y, Pan C, Zhang H, Yang S, Ren X, Li J, Huang G. Eur. J. Org. Chem. 2014; 2754
• 41 Babu BM, Kumar GS, Thakur PB, Bangade VM, Meshram HM. Tetrahedron Lett. 2014; 55: 3473
• 42 Yan R.-L, Yan H, Ma C, Ren Z.-Y, Gao X.-A, Huang G.-S, Liang Y.-M. J. Org. Chem. 2012; 77: 2024
• 43 Yan H, Yan R, Yang S, Gao X, Wang Y, Huang G, Liang Y. Chem. Asian J. 2012; 7: 2028
• 44 Puthiaraj P, Ramu A, Pitchumani K. Asian J. Org. Chem. 2014; 3: 784
• 45 Rajanarendar E, Reddy KG, Krishna SR, Srinivas M. J. Heterocycl. Chem. 2015; in press; DOI: 10.1002/jhet.2146
• 46 Nair DK, Mobin SM, Namboothiri IN. N. Org. Lett. 2012; 14: 4580
• 47 Nayak M, Kanojiya S, Batra S. Synthesis 2009; 431
• 48 He C, Hao J, Xu H, Mo Y, Liu H, Han J, Lei A. Chem. Commun. 2012; 48: 11073
• 49 Gao Y, Yin M, Wu W, Huang H, Jiang H. Adv. Synth. Catal. 2013; 355: 2263
• 50 Zeng J, Tan YJ, Leow ML, Liu X.-W. Org. Lett. 2012; 14: 4386
• 51 Wu Z, Pan Y, Zhou X. Synthesis 2011; 2255
• 52 Liu Z, Chen Z.-C, Zheng Q.-G. Synth. Commun. 2004; 34: 361
• 53 Dixon LI, Carroll MA, Gregson TJ, Ellames GJ, Harrington RW, Clegg W. Org. Biomol. Chem. 2013; 11: 5877
• 54 Liu P, Deng C.-L, Lei X, Lin G.-q. Eur. J. Org. Chem. 2011; 7308
• 55 Mareev AV, Tikhonov AV, Afonin AV, Ushakov IA, Medvedeva AS. Russ. J. Org. Chem. 2005; 41: 1397
• 56 Mareev AV, Medvedeva AS, Mitroshina IV, Afonin AV, Ushakov IA, Romanenko GV, Tret’yakov EV. Russ. J. Org. Chem. 2008; 44: 1718
• 57 Adib M, Mahdavi M, Abbasi A, Jahromi AH, Bijanzadeh HR. Tetrahedron Lett. 2007; 48: 3217
• 58a Bienaymé H, Bouzid K. Angew. Chem. Int. Ed. 1998; 37: 2234
• 58b Groebke K, Weber L, Mehlin F. Synlett 1998; 661
• 58c Blackburn C. Tetrahedron Lett. 1998; 39: 5469
• 59a Maleki A, Javanshir S, Naimabadi M. RSC Adv. 2014; 4: 30229
• 59b Mert-Balci F, Conrad J, Beifuss U. ARKIVOC 2012; (iii): 243
• 59c Rostamnia S, Lamei K, Mohammadquli M, Sheykhan M, Heydari A. Tetrahedron Lett. 2012; 53: 5257
• 59d Khan AT, Sidick Basha R, Lal M. Tetrahedron Lett. 2012; 53: 2211
• 59e Maiti B, Chanda K, Selvaraju M, Tseng C.-C, Sun C.-M. ACS Comb. Sci. 2013; 15: 291
• 59f Shaabani A, Seyyedhamzeh M, Shaabani S, Ganji N. Res. Chem. Intermed. 2013; 1
• 59g Daemi H, Rad RR, Barikani M, Adib M. Appl. Catal. A 2013; 468: 10
• 59h Sandulenko Y, Krasavin M. Chem. Heterocycl. Compd. 2012; 48: 606
• 59i Sanaeishoar T, Tavakkoli H, Mohave F. Appl. Catal. A 2014; 470: 56
• 59j Puttaraju KB, Shivashankar K. RSC Adv. 2013; 3: 20883
• 59k Sadjadi S, Eskandari M. Monatsh. Chem. 2012; 143: 653
• 59l Mironov MA, Tokareva MI, Ivantsova MN, Mokrushin VS. Russ. Chem. Bull. 2006; 55: 1835
• 59m Oskooie HA, Amini M, Heravi MM, Bamoharram FF. Chin. J. Chem. 2010; 28: 299
• 59n Shaabani A, Rezazadeh F, Soleimani E. Monatsh. Chem. 2008; 139: 931
• 59o Rousseau AL, Matlaba P, Parkinson CJ. Tetrahedron Lett. 2007; 48: 4079
• 59p Schwerkoske J, Masquelin T, Perun T, Hulme C. Tetrahedron Lett. 2005; 46: 8355
• 59q Akbarzadeh R, Shakibaei G, Bazgir A. Monatsh. Chem. 2010; 141: 1077
• 59r Sandulenko Y, Komarov A, Rufanov K, Krasavin M. Tetrahedron Lett. 2008; 49: 5990
• 60a Lyon MA, Kercher TS. Org. Lett. 2004; 6: 4989
• 60b Sharma A, Li H.-y. Synlett 2011; 1407
• 61 Ramesha AB, Raghavendra GM, Nandeesh KN, Rangappa KS, Mantelingu K. Tetrahedron Lett. 2013; 54: 95
• 62 Adib M, Sheikhi E, Rezaei N. Tetrahedron Lett. 2011; 52: 3191
• 63 Marandi G, Saghatforoush L, Mendoza-Meroño R, García-Granda S. Tetrahedron Lett. 2014; 55: 3052
• 64 DiMauro EF, Kennedy JM. J. Org. Chem. 2007; 72: 1013
• 65 Masquelin T, Bui H, Brickley B, Stephenson G, Schwerkoske J, Hulme C. Tetrahedron Lett. 2006; 47: 2989
• 66 Polyakov AI, Eryomina VA, Medvedeva LA, Tihonova NI, Listratova AV, Voskressensky LG. Tetrahedron Lett. 2009; 50: 4389
• 67 Abdollahi-Alibeik M, Rezaeipoor-Anari A. Catal. Sci. Technol. 2014; 4: 1151
• 68 Venkatesham R, Manjula A, Rao BV. J. Heterocycl. Chem. 2011; 48: 942
• 69 Adib M, Sheibani E, Zhu L.-G, Mirzaei P. Tetrahedron Lett. 2008; 49: 5108
• 70 Arnould M, Hiebel M.-A, Massip S, Léger JM, Jarry C, Berteina-Raboin S, Guillaumet G. Chem. Eur. J. 2013; 19: 12249
• 71 Yang A, Jiang R, Khorev O, Yu T, Zhang Y, Ma L, Chen G, Shen J, Meng T. Adv. Synth. Catal. 2013; 355: 1984
• 72 Sun H, Zhou H, Khorev O, Jiang R, Yu T, Wang X, Du Y, Ma Y, Meng T, Shen J. J. Org. Chem. 2012; 77: 10745
• 73 Tyagi V, Khan S, Bajpai V, Gauniyal HM, Kumar B, Chauhan PM. S. J. Org. Chem. 2012; 77: 1414
• 74 El Akkaoui A, Hiebel M.-A, Mouaddib A, Berteina-Raboin S, Guillaumet G. Tetrahedron 2012; 68: 9131
• 75 Peshkov VA, Pereshivko OP, Van der Eycken EV. Chem. Soc. Rev. 2012; 41: 3790
• 76 Chernyak N, Gevorgyan V. Angew. Chem. Int. Ed. 2010; 49: 2743
• 77 Liu P, Fang L.-s, Lei X, Lin G.-q. Tetrahedron Lett. 2010; 51: 4605


• 78a Siddiqui IR, Rai P, Rahila, Srivastava A, Shamim S. Tetrahedron Lett. 2014; 55: 1159
• 78b Guntreddi T, Allam BK, Singh KN. Synlett 2012; 23: 2635
• 78c Guchhait SK, Chandgude AL, Priyadarshani G. J. Org. Chem. 2012; 77: 4438
• 78d Maleki A. Helv. Chim. Acta 2014; 97: 587
• 78e Reddy BV. S, Sivaramakrishna Reddy P, Jayasudhan Reddy Y, Yadav JS. Tetrahedron Lett. 2011; 52: 5789
• 78f Mishra S, Ghosh R. Synthesis 2011; 3463
• 79 Palani T, Park K, Kumar MR, Jung HM, Lee S. Eur. J. Org. Chem. 2012; 5038
• 80 Ge W, Zhu X, Wei Y. Eur. J. Org. Chem. 2013; 6015
• 81 Mohan DC, Rao SN, Ravi C, Adimurthy S. Asian J. Org. Chem. 2014; 3: 609
• 82 Wang Y, Saha B, Li F, Frett B, Li H.-y. Tetrahedron Lett. 2014; 55: 1281
• 83 Cao H, Liu X, Zhao L, Cen J, Lin J, Zhu Q, Fu M. Org. Lett. 2014; 16: 146
• 84 Barun O, Ila H, Junjappa H, Singh OM. J. Org. Chem. 2000; 65: 1583
• 85 Wang H, Wang Y, Liang D, Liu L, Zhang J, Zhu Q. Angew. Chem. Int. Ed. 2011; 50: 5678
• 86 Chioua M, Soriano E, Infantes L, Jimeno ML, Marco-Contelles J, Samadi A. Eur. J. Org. Chem. 2013; 35
• 87 Husinec S, Markovic R, Petkovic M, Nasufovic V, Savic V. Org. Lett. 2011; 13: 2286
• 88 Chandra Mohan D, Sarang NB, Adimurthy S. Tetrahedron Lett. 2013; 54: 6077
• 89 Chandra Mohan D, Nageswara Rao S, Adimurthy S. J. Org. Chem. 2013; 78: 1266
• 90 Aliev ZG, Atovmyan LO, Kataev SS, Zalesov VV. Chem. Heterocycl. Compd. 2007; 43: 377
• 91 Sokolov VB, Aksinenko AY, Martynov IV. Russ. Chem. Bull. 2005; 54: 470
• 92 Aksinenko AY, Goreva TV, Epishina TA, Sokolov VB. J. Fluorine Chem. 2012; 137: 105
• 93 Gomez O, Salgado-Zamor H, Reyes A, Campos Maria E. Heterocycl. Commun. 2010; 16: 99
• 94 Basilio-Lopes A, de Aquino TM, Mongeot A, Bourguignon J.-J, Schmitt M. Tetrahedron Lett. 2012; 53: 2583
• 95 Barolo SM, Wang Y, Rossi RA, Cuny GD. Tetrahedron 2013; 69: 5487
• 96 Wang H, Wang Y, Peng C, Zhang J, Zhu Q. J. Am. Chem. Soc. 2010; 132: 13217
• 97 Masters K.-S, Rauws TR. M, Yadav AK, Herrebout WA, Van der Veken B, Maes BU. W. Chem. Eur. J. 2011; 17: 6315
• 98 Kolodych S, Rasolofonjatovo E, Chaumontet M, Nevers M.-C, Créminon C, Taran F. Angew. Chem. Int. Ed. 2013; 52: 12056
• 99 Liang D, He Y, Liu L, Zhu Q. Org. Lett. 2013; 15: 3476
• 100 Rao DN, Rasheed SK, Vishwakarma RA, Das P. RSC Adv. 2014; 4: 25600
• 101 Sokolov VB, Aksinenko AY, Epishina TA, Goreva TV. Russ. Chem. Bull. 2009; 58: 631
• 102 Katritzky AR, Xu Y.-J, Tu H. J. Org. Chem. 2003; 68: 4935
• 103 Krasovskiy AL, Nenajdenko VG, Balenkova ES. Synthesis 2002; 1379
• 104 Hamdouchi C, Zhong B, Mendoza J, Collins E, Jaramillo C, De Diego JE, Robertson D, Spencer CD, Anderson BD, Watkins SA, Zhang F, Brooks HB. Bioorg. Med. Chem. Lett. 2005; 15: 1943
• 105 Matsumoto S, Miyamoto N, Hirayama T, Oki H, Okada K, Tawada M, Iwata H, Nakamura K, Yamasaki S, Miki H, Hori A, Imamura S. Bioorg. Med. Chem. 2013; 21: 7686
• 106 Rozentsveig IB, Serykh VY, Chernysheva GN, Chernyshev KA, Kondrashov EV, Tretyakov EV, Romanenko GV. Eur. J. Org. Chem. 2013; 368
• 107 Tu S, Zhang J, Jia R, Jiang B, Zhang Y, Yao C, Jiang H. Chem. Lett. 2007; 36: 222
• 108 Ducray R, Boutron P, Didelot M, Germain H, Lach F, Lamorlette M, Legriffon A, Maudet M, Ménard M, Pasquet G, Renaud F, Simpson I, Young GL. Tetrahedron Lett. 2010; 51: 4755
• 109 Collins MR, Huang Q, Ornelas MA, Scales SA. Tetrahedron Lett. 2010; 51: 3528
• 110 Yu J, Jin Y, Zhang H, Yang X, Fu H. Chem. Eur. J. 2013; 19: 16804
• 111 Attanasi OA, Bianchi L, Campisi LA, Crescentini LD, Favi G, Mantellini F. Org. Lett. 2013; 15: 3646
• 112 Huang H, Ji X, Tang X, Zhang M, Li X, Jiang H. Org. Lett. 2013; 15: 6254
• 113 Sandeep C, Padmashali B, Kulkarni RS. Tetrahedron Lett. 2013; 54: 6411
• 114 Deyanov AB, Konshin ME. Chem. Heterocycl. Compd. 2004; 40: 510
• 115 Shao N, Pang G.-X, Yan C.-X, Shi G.-F, Cheng Y. J. Org. Chem. 2011; 76: 7458
• 116 Motevalli K, Yaghoubi Z, Mirzazadeh R. E-J. Chem. 2012; 9: 1047 http://www.hindawi.com/journals/jchem/
• 117 Kianmehr E, Ghanbari M, Niri MN, Faramarzi R. J. Comb. Chem. 2009; 12: 41
• 118 Prasanna P, Kumar SV, Gunasekaran P, Perumal S. Tetrahedron Lett. 2013; 54: 3740
• 119 Yan CG, Wang QF, Song XK, Sun J. J. Org. Chem. 2009; 74: 710
• 120 Zhu H, Shao N, Chen T, Zou H. Chem. Commun. 2013; 49: 7738
• 121 Bakherad M, Nasr-Isfahani H, Keivanloo A, Doostmohammadi N. Tetrahedron Lett. 2008; 49: 3819
• 122 Bakherad M, Keivanloo A, Hashemi M. Synth. Commun. 2009; 39: 1002
• 123 Talbot EP. A, Richardson M, McKenna JM, Toste FD. Adv. Synth. Catal. 2014; 356: 687
• 124a Sawyer JS, Macdonald TL. Tetrahedron Lett. 1988; 29: 4839
• 124b Kiselyov AS, Strekowski L. J. Org. Chem. 1993; 58: 4476
• 124c Umemoto T, Tomizawa G. Tetrahedron Lett. 1987; 28: 2705
• 125 Kiselyov AS. Tetrahedron Lett. 2005; 46: 4487
• 126 Proença MF, Costa M. Tetrahedron 2010; 66: 4542
• 127 Begunov RS, Ryzvanovich GA, Firgang SI. Russ. J. Org. Chem. 2004; 40: 1694
• 128 Sokolov AA, Syroeshkin MA, Begunov RS, Rusakova NN, Gultyai VP. Mendeleev Commun. 2012; 22: 312
• 129 Dong L, Huang J.-R, Qu C.-H, Zhang Q.-R, Zhang W, Han B, Peng C. Org. Biomol. Chem. 2013; 11: 6142
• 130 Nagaraj M, Boominathan M, Muthusubramanian S, Bhuvanesh N. Synlett 2012; 23: 1353
• 131 Nadipuram AK, Kerwin SM. Tetrahedron 2006; 62: 3798
• 132 Ram VJ, Agarwal N, Sharon A, Maulik PR. Tetrahedron Lett. 2002; 43: 307
• 133 Li M, Shao P, Wang S.-W, Kong W, Wen L.-R. J. Org. Chem. 2012; 77: 8956
• 134 Wen L.-R, Jiang C.-Y, Li M, Wang L.-J. Tetrahedron 2011; 67: 293
• 135 Wen L.-R, Li Z.-R, Li M, Cao H. Green Chem. 2012; 14: 707
• 136 Chen X, Zhu D, Wang X, Yan S, Lin J. Tetrahedron 2013; 69: 9224
• 137 Tung Y.-S, Coumar MS, Wu Y.-S, Shiao H.-Y, Chang J.-Y, Liou J.-P, Shukla P, Chang C.-W, Chang C.-Y, Kuo C.-C, Yeh T.-K, Lin C.-Y, Wu J.-S, Wu S.-Y, Liao C.-C, Hsieh H.-P. J. Med. Chem. 2011; 54: 3076
• 138 Orlov VD, Kharchenko YV, Gella IM, Omel’chenko IV, Shishkin OV. Chem. Heterocycl. Compd. 2012; 48: 1204
• 139 Hammouda M, Abou Zeid ZM, Metwally MA. Chem. Heterocycl. Compd. 2005; 41: 1525
• 140 Kazemi Movahed S, Dabiri M, Bazgir A. Helv. Chim. Acta 2013; 96: 525
• 141 Barluenga J, García-Rodríguez J, Martínez S, Suárez-Sobrino AL, Tomás M. Chem. Eur. J. 2006; 12: 3201
• 142 Sivakumar S, Kumar RR. Asian J. Org. Chem. 2014; 3: 974
• 143 Kato J.-y, Ito Y, Ijuin R, Aoyama H, Yokomatsu T. Org. Lett. 2013; 15: 3794
• 144 Kethe A, Naredla RR, Klumpp DA. Helv. Chim. Acta 2013; 96: 1457
• 145 Cai Q, Li Z, Wei J, Fu L, Ha C, Pei D, Ding K. Org. Lett. 2010; 12: 1500
• 146 Dhiman S, Pericherla K, Nandwana NK, Kumar D, Kumar A. J. Org. Chem. 2014; 79: 7339
• 147 Dai W, Petersen JL, Wang KK. J. Org. Chem. 2005; 70: 6647
• 148 Jeffery D, Prager RH, Turner D, Dreimanis M. Tetrahedron 2002; 58: 9965
• 149 Khalafy J, Setamdideh D, Dilmaghani K. Molecules 2002; 7: 907 ; http://www.mdpi.com/journal/molecules
• 150a Khalafy J, Ebrahimlo AR. M, Eisavi R, Dilmaghani KA. ARKIVOC 2005; (xiv): 59
• 150b Azimi C, Sepehraddin F, Tahazade H. Orient. J. Chem. 2013; 29: 1443
• 150c Baradarani MM, Khalafy J, Khadivi S, Poursattar Marjani A. Chem. Heterocycl. Compd. 2008; 44: 594
• 151 Li M, Li T, Zhao K, Wang M, Wen L. Chin. J. Chem. 2013; 31: 1033