Synlett, Table of Contents Synlett 2018; 29(16): 2191-2194DOI: 10.1055/s-0037-1610653 letter © Georg Thieme Verlag Stuttgart · New York Pd-Catalyzed Oxidation of Aldimines to Amides Shanshan Gao School of Materials Science and Chemical Engineering, Ningbo University, 315211 Ningbo, P. R. of China Email: luojunfei@nbu.edu.cn , Yaorui Ma School of Materials Science and Chemical Engineering, Ningbo University, 315211 Ningbo, P. R. of China Email: luojunfei@nbu.edu.cn , Weidong Chen School of Materials Science and Chemical Engineering, Ningbo University, 315211 Ningbo, P. R. of China Email: luojunfei@nbu.edu.cn , Junfei Luo* School of Materials Science and Chemical Engineering, Ningbo University, 315211 Ningbo, P. R. of China Email: luojunfei@nbu.edu.cn › Author Affiliations Recommend Article Abstract Buy Article All articles of this category Abstract Methods for the synthesis of amides via the direct oxidation of imines are rarely reported. Here we report an efficient method for Pd-catalyzed oxidation of imines to amide derivatives by the use of cheap aqueous tert-butyl hydroperoxide as an oxidant through a Wacker-type reaction. This method is practically convenient and displays high functional group tolerance, allowing a variety of imines to transform into the corresponding amide derivatives in moderate to good yields. Key words Key wordsPd-catalyzed - amides - imines - oxidation - tert-butyl hydroperoxide Full Text References References and Notes 1 Greenberg A. The Amide Linkage: Selected Structural Aspects in Chemistry, Biochemistry, and Materials Science. Wiley-Interscience; New York: 2000 2a Humphrey JM. Chamberlin AR. Chem. Rev. 1997; 97: 2243 2b Wipf P. In Handbook of Reagents for Organic Synthesis. Wiley and Sons; New York: 2005 3a Teichert A. Jantos K. Harms K. Studer A. Org. Lett. 2004; 6: 3477 3b Shendage DM. Froehlich R. Haufe G. Org. Lett. 2004; 6: 3675 3c Montalbetti CA. G. N. Falque V. Tetrahedron 2005; 61: 10827 3d Black DA. Arndtsen BA. Org. Lett. 2006; 8: 1991 3e Katritzky AR. Cai C. Singh SK. J. Org. Chem. 2006; 71: 3375 4a Lanigan RM. Sheppard TD. Eur. J. Org. Chem. 2013; 33: 7453 4b Lundberg H. Tinnis F. Selander N. Adolfsson H. Chem. Soc. Rev. 2014; 42: 2714 5a Schmidt RF. Ber. Dtsch. Chem. Ges. 1924; 57: 704 5b Yao L. Aube J. J. Am. Chem. Soc. 2007; 129: 2766 6a Ramalingan C. Park Y.-T. J. Org. Chem. 2007; 72: 4536 6b Augustine JK. Kumar R. Bombrun A. Mandal AB. Tetrahedron Lett. 2011; 52: 1074 7a Martinelli JR. Clark TP. Watson DA. Munday RH. Buchwald SL. Angew. Chem. Int. Ed. 2007; 46: 8460 7b Chang JW. W. Chan PW. H. Angew. Chem. Int. Ed. 2008; 47: 1138 7c Kolakowski RV. Shangguan N. Sauers RR. Williams LJ. J. Am. Chem. Soc. 2006; 128: 5695 7d Lin Y.-S. Alper H. Angew. Chem. Int. Ed. 2001; 40: 779 7e Uozumi Y. Arii T. Watanabe T. J. Org. Chem. 2001; 66: 5272 7f Namayakkara P. Alper H. Chem. Commun. 2003; 2384 7g Knapton D. Meyer TY. Org. Lett. 2004; 6: 687 7h Uenoyama Y. Fukuyama T. Nobuta O. Matsubara H. Ryu I. Angew. Chem. Int. Ed. 2005; 44: 1075 7i Gunanathan C. Ben-David Y. Milstein D. Science 2007; 317: 790 7j Nordstrom LU. Vogt H. Madsen R. J. Am. Chem. Soc. 2008; 130: 17672 7k Zhang Y. Chen C. Ghosh SC. Li Y. Hong SH. Organometallics 2010; 29: 1374 7l Muthaiah S. Ghosh SC. Jee J.-E. Chen C. Zhang J. Hong SH. J. Org. Chem. 2010; 75: 3002 7m Kim K. Kang B. Hong SH. Tetrahedron 2015; 71: 4565 7n Islam SM. Ghosh K. Roy AS. Molla RA. Appl. Organometal. Chem. 2014; 28: 900 8a Ding Y. Zhang X. Zhang D. Chen Y. Wu Z. Wang P. Xue W. Song B. Yang S. Tetrahedron Lett. 2015; 56: 831 8b Whittaker AM. Dong VM. Angew. Chem. Int. Ed. 2015; 54: 1312 8c Mamaghani M. Shirini F. Sheykhan M. Mohsenimehr M. RSC Adv. 2015; 5: 44524 8d Lu S.-Y. Badsara SS. Wu Y.-C. Reddy DM. Lee C.-F. Tetrahedron Lett. 2016; 57: 633 8e Wu Z. Hull KL. Chem. Sci. 2016; 7: 969 8f Ekoue-Kovi K. Wolf C. Org. Lett. 2007; 9: 3429 9 Zultanski SL. Zhao J. Stahl SS. J. Am. Chem. Soc. 2016; 138: 6416 10 An G.-i. Kim M. Kim JY. Rhee H. Tetrahedron Lett. 2003; 44: 2183 11 Seo H.-A. Cho Y.-H. Lee Y.-S. Cheon C.-H. J. Org. Chem. 2015; 80: 11993 12 Larsen J. Jorgensen KA. Christensen D. J. Chem. Soc., Perkin Trans. 1 1991; 1187 13 Mohamed MA. Yamada K.-i. Tomioka K. Tetrahedron Lett. 2009; 50: 3436 14a Smidt J. Hafner W. Jira R. Sieber R. Sedlmeier S. Sabel A. Angew. Chem., Int. Ed. Engl. 1962; 1: 80 14b Clement WH. Selwitz CM. J. Org. Chem. 1964; 29: 241 14c Tsuji J. Synthesis 1984; 369 14d Tsuji J. Trost BM. Fleming I. Comprehensive Organic Synthesis . Vol. 7. Pergamon Press; New York: 1991: 449 15 Zhang L. Wang W. Wang A. Cui Y. Yang X. Huang Y. Liu X. Liu W. Son J. Oji H. Zhang T. Green Chem. 2013; 15: 2680 16 Typical Procedure for the Preparation of N-Phenylbenzamide (2a) Pd(OAc)2 (0.01 mmol), N,1-diphenylmethanimine (1a, 0.2 mmol), TBHP (70 % solution in H2O, 6.0 equiv, 1.2 mmol), and DCE (1.5 mL) were added to a vial. The reaction mixture was stirred under 120 °C for 5 h. After that time, the reaction mixture was quenched with saturated Na2SO3 solution (consumption of residual TBHP) and extracted with EtOAc. The organic layer was separated and dried with Na2SO4. Removal of solvent followed by flash column chromatographic purification (EtOAc/PE) afforded N-phenylbenzamide (2a) as a white solid (33.5 mg, yield 85%). 1H NMR (400 MHz, CDCl3): δ = 7.94 (br s, 1 H), 7.86 (d, J = 7.3 Hz, 2 H), 7.65 (d, J = 7.9 Hz, 2 H), 7.54 (t, J = 7.3 Hz, 1 H), 7.47 (t, J = 7.4 Hz, 2 H), 7.36 (t, J = 7.8 Hz, 2 H), 7.15 (t, J = 7.4 Hz, 1 H) ppm. 13C NMR (101 MHz, CDCl3): δ = 165.7, 137.9, 135.0, 131.9, 129.1, 128.8, 127.0, 124.6, 120.2 ppm. Supplementary Material Supplementary Material Supporting Information
