A Highly Efficient Copper(II)-Catalyzed Cross-Dehydrogenative-Coupling Reaction of N-Arylglycine Esters with 2-Arylimidazo[1,2-a]pyridines

Abstract

A rapid and highly efficient copper(II)-catalyzed cross-dehydrogenative coupling (CDC) reaction of N-arylglycine esters with imidazo[1,2-a]pyridines has been described. A broad range of N-arylglycine esters underwent the CDC reaction smoothly with 2-arylimidazo[1,2-a]pyridines to give α-substituted α-amino acid esters in excellent yields. This synthetic method has the advantages of high yields, good functional groups compatibility, simple operation, and mild reaction conditions. A possible mechanism for the CDC reaction is also proposed. The use of a copper salt as the catalyst and air as the terminal oxidant makes this transformation sustainable and practical.

Key words

cross-dehydrogenative coupling - copper - glycine ester - imidazo­[1,2-a]pyridine - imine

• References

• 1 Bagdi AK. Santra S. Monir K. Hajra A. Chem. Commun. 2015; 51: 1555
• 2a Rupert KC. Henry JR. Dodd JH. Wadsworth SA. Cavender DE. Olini GC. Fahmy B. Siekierka J. Bioorg. Med. Chem. Lett. 2003; 13: 347
• 2b Harrison TS. Keating GM. CNS Drugs 2005; 19: 65
• 2c Enguehard-Gueiffier C. Gueiffier A. Mini-Rev. Med. Chem. 2007; 7: 888
• 2d Hanson SM. Morlock EV. Satyshur KA. Czajkowski C. J. Med. Chem. 2008; 51: 7243
• 2e Wiegand MH. Drugs 2008; 68: 2411
• 2f Al-Tel TH. Al-Qawasmeh RA. Zaarour R. Eur. J. Med. Chem. 2011; 46: 1874
• 2g Andreani A. Granaiola M. Locatelli A. Morigi R. J. Med. Chem. 2012; 55: 2078
• 3a Yang H. Yang L. Li Y. Zhang F. Liu H. Yi B. Catal. Commun. 2012; 26: 11
• 3b Kim O. Jeong Y. Lee H. Hong S.-S. Hong S. J. Med. Chem. 2011; 54: 2455
• 3c Chernyak N. Gevorgyan V. Angew. Chem. Int. Ed. 2010; 49: 2743

For selected papers, see:
• 4a Ravi C. Mohan CD. Adimurthy S. Org. Lett. 2014; 16: 2978
• 4b Kaswan P. Porter A. Pericherla K. Simone M. Peters S. Kumar A. DeBoef B. Org. Lett. 2015; 17: 5208
• 4c Wang Q. Qi Z. Xie F. Li X. Adv. Synth. Catal. 2015; 357: 355
• 4d Monir K. Bagdi AK. Ghosh M. Hajra A. J. Org. Chem. 2015; 80: 1332
• 4e Yang D. Yan K. Wei W. Li G. Lu S. Zhao C. Tian L. Wang H. J. Org. Chem. 2015; 80: 11703
• 4f Yadav M. Dara S. Saikam V. Kumar M. Aithagani SK. Paul S. Vishwakarma RA. Singh PP. Eur. J. Org. Chem. 2015; 6526
• 4g Ji X.-M. Zhou S.-J. Chen F. Zhang X.-G. Tang R.-Y. Synthesis 2015; 47: 659
• 4h Jiao J. Wei L. Ji X.-M. Hu M.-L. Tang R.-Y. Adv. Synth. Catal. 2016; 358: 268
• 4i Mondal S. Samanta S. Jana S. Hajra A. J. Org. Chem. 2017; 82: 4504

For selected reviews, see:
• 5a Li C.-J. Acc. Chem. Res. 2009; 42: 335
• 5b Ashenhurst JA. Chem. Soc. Rev. 2010; 39: 540
• 5c Yeung CS. Dong VM. Chem. Rev. 2011; 111: 1215
• 5d Girard SA. Knauber T. Li C.-J. Angew. Chem. Int. Ed. 2014; 53: 74
• 5e Liu C. Yuan J. Gao M. Tang S. Li W. Shi R. Lei A. Chem. Rev. 2015; 115: 12138
• 6a Zhao L. Li C.-J. Angew. Chem. Int. Ed. 2008; 47: 7075
• 6b Xie J. Huang Z.-Z. Angew. Chem. Int. Ed. 2010; 49: 10181
• 6c Zhang G. Zhang Y. Wang R. Angew. Chem. Int. Ed. 2011; 50: 10429
• 6d Gao X.-W. Meng Q.-Y. Xiang M. Chen B. Feng K. Tung C.-H. Wu L.-Z. Adv. Synth. Catal. 2013; 355: 2158
• 6e Zhu Z.-Q. Bai P. Huang Z.-Z. Org. Lett. 2014; 16: 4881
• 6f Wei W.-T. Song R.-J. Li J.-H. Adv. Synth. Catal. 2014; 356: 1703
• 6g Gao X.-W. Meng Q.-Y. Li J.-X. Zhong J.-J. Lei T. Li X.-B. Tung C.-H. Wu L.-Z. ACS Catal. 2015; 5: 2391
• 6h Zhu Z.-Q. Xie Z.-B. Le Z.-G. J. Org. Chem. 2016; 81: 9449
• 6i Zhu Z.-Q. Xie Z.-B. Le Z.-G. Synlett 2017; 28: 485
• 7a Zhao L. Basle O. Li C.-J. Proc. Natl. Acad. Sci. U.S.A. 2009; 11: 4106
• 7b Li K. Tan G. Huang J. Song F. You J. Angew. Chem. Int. Ed. 2013; 52: 12942
• 7c Huo C. Yuan Y. Wu M. Jia X. Wang X. Chen F. Tang J. Angew. Chem. Int. Ed. 2014; 53: 13544
• 7d Huo C. Wang C. Wu M. Jia X. Xie H. Yuan Y. Adv. Synth. Catal. 2014; 356: 411
• 7e Salman M. Zhu Z.-Q. Huang Z.-Z. Org. Lett. 2016; 18: 1526
• 7f Xie Z. Liu X. Liu L. Org. Lett. 2016; 18: 2982
• 7g Xie Z. Jia J. Liu X. Liu L. Adv. Synth. Catal. 2016; 358: 919
• 7h Jiao J. Zhang J.-R. Liao Y.-Y. Xu L. Hu M. Tang R.-Y. RSC Adv. 2017; 7: 30152