Photocatalyzed difluoroalkylation of pyridine N-oxides

References

• (a) Smart, B. E. Fluorine Substituent Effects (on Bioactivity). J. Fluorine Chem. 2001, 109, 3–11. DOI: 10.1016/S0022-1139(01)00375-X.
   Web of Science ®Google Scholar
  (b) Müller, K.; Faeh, C.; Diederich, F. Fluorine in Pharmaceuticals: Looking beyond Intuition. Science 2007, 317, 1881–1886., DOI: 10.1126/science.1131943.
   PubMed Web of Science ®Google Scholar
  (c) O’Hagan, D. Chem. Soc. Rev. 2008, 37, 308–319. DOI: 10.1039/B711844A.
   PubMed Web of Science ®Google Scholar
  (d) Meanwell, N. A. Synopsis of Some Recent Tactical Application of Bioisosteres in Drug Design. J. Med. Chem. 2011, 54, 2529–2591. DOI: 10.1021/jm1013693.
   PubMed Web of Science ®Google Scholar
  (e) Xing, B.; Ni, C.; Hu, J. Copper-Mediated Di- and Monofluoromethanesulfonylation of Arenediazonium Tetrafluoroborates: Probing the Fluorine Effect. Chin. J. Chem. 2018, 36, 206–212. DOI: 10.1002/cjoc.201700748.
   Web of Science ®Google Scholar
• (a) Cadicamo, C. D.; Courtieu, J.; Deng, H.; Meddour, A.; O'Hagan, D. Enzymatic Fluorination in Streptomyces Cattleya Takes Place with an Inversion of Configuration Consistent with an SN2 Reaction Mechanism. ChemBioChem. 2004, 5, 685–690. DOI: 10.1002/cbic.200300839.
   PubMed Web of Science ®Google Scholar
  (b) Purser, S.; Moore, P. R.; Swallow, S.; Gouverneur, V. Fluorine in Medicinal Chemistry. Chem. Soc. Rev. 2008, 37, 320–330. DOI: 10.1039/b610213c.
   PubMed Web of Science ®Google Scholar
  (c) Ojima, I. Fluorine in Medicinal Chemistry and Chemical Biology; Wiley-Blackwell: Chichester, 2009.
   Google Scholar
  (d) Liang, T.; Neumann, C. N.; Ritter, T. Introduction of Fluorine and Fluorine-Containing Functional Groups. Angew. Chem. Int. Ed. Engl. 2013, 52, 8214–8264. DOI: 10.1002/anie.201206566.
   PubMed Web of Science ®Google Scholar
  (e) Feng, Z.; Xiao, Y.-L.; Zhang, X. Transition-Metal (Cu, Pd, Ni)-Catalyzed Difluoroalkylation via Cross-Coupling with Difluoroalkyl Halides. Acc. Chem. Res. 2018, 51, 2264–2278. DOI: 10.1021/acs.accounts.8b00230.
   PubMed Web of Science ®Google Scholar
• (a) Middleton, W. J.; Bingham, E. M. Alpha.,.Alpha.-Difluoroarylacetic Acids: Preparation from (Diethylamino)Sulfur Trifluoride and .alpha.-Oxoarylacetates. J. Org. Chem. 1980, 45, 2883–2887. DOI: 10.1021/jo01302a025.
   Web of Science ®Google Scholar
  (b) Yang, Y.-Y.; Xu, J.; You, Z.-W.; Xu, X.-Y.; Qiu, X.-L.; Qing, F.-L. Synthesis of 3′,3′-Difluoro-2′-Hydroxymethyl-4′,5′-Unsaturated Carbocyclic Nucleosides. Org. Lett. 2007, 9, 5437–5440. DOI: 10.1021/ol7023955.
   PubMed Web of Science ®Google Scholar
  (c) Otsuka, T.; Ishii, A.; Dub, P. A.; Ikariya, T. Practical Selective Hydrogenation of α-Fluorinated Esters with Bifunctional Pincer-Type Ruthenium(II) Catalysts Leading to Fluorinated Alcohols or Fluoral Hemiacetals. J. Am. Chem. Soc. 2013, 135, 9600–9603. DOI: 10.1021/ja403852e.
   PubMed Web of Science ®Google Scholar
  (d) Zhang, D.; Gao, X.; Min, Q.; Gu, Y.; Berthon, G.; Zhang, X. Chem. Eur. J. DOI: 10.1002/chem.202200642.
   Google Scholar
• Hertel, L. W.; Ternansky, R. J. Fluorine-Containing Antiviral and Anticancer Compounds. In Organofluorine Compounds in Medicinal Chemistry and Biomedical Applications; Filler, R., Kobayashi, Y., Yagupolskii, L. M., Eds.; Elsevier: Amsterdam, 1993; p 23.
   Google Scholar
• Melvin, P. R.; Ferguson, D. M.; Schimler, S. D.; Bland, D. C.; Sanford, M. S. Room Temperature Deoxyfluorination of Benzaldehydes and α-Ketoesters with Sulfuryl Fluoride and Tetramethylammonium Fluoride. Org. Lett. 2019, 21, 1350–1353. DOI: 10.1021/acs.orglett.9b00054.
   PubMed Web of Science ®Google Scholar
• (a) Kreutter, K. D.; Lu, T.; Lee, L.; Giardino, E. C.; Patel, S.; Huang, H.; Xu, G.; Fitzgerald, M.; Haertlein, B. J.; Mohan, V.; et al. Orally Efficacious Thrombin Inhibitors with Cyanofluorophenylacetamide as the P2 Motif. Bioorg. Med. Chem. Lett. 2008, 18, 2865–2870. DOI: 10.1016/j.bmcl.2008.03.087.
   PubMed Web of Science ®Google Scholar
  (b) Fujikawa, K.; Fujioka, Y.; Kobayashi, A.; Amii, H. A New Method for Aromatic Difluoromethylation: Copper-Catalyzed Cross-Coupling and Decarboxylation Sequence from Aryl Iodides. Org. Lett. 2011, 13, 5560–5563. DOI: 10.1021/ol202289z.
   PubMed Web of Science ®Google Scholar
  (c) Fujikawa, K.; Kobayashi, A.; Amii, H. Synthesis 2012, 44, 3015–3018.
   Web of Science ®Google Scholar
  (d) Arlow, S. I.; Hartwig, J. F. Synthesis of Aryldifluoroamides by Copper-Catalyzed Cross-Coupling. Angew. Chem. Int. Ed. Engl. 2016, 55, 4567–4572. DOI: 10.1002/anie.201600105.
   PubMedGoogle Scholar
• (a) Bolton, R.; Williams, G. H. Homolytic Arylation of Aromatic and Polyfluoroaromatic Compounds. Chem. Soc. Rev. 1986, 15, 261–289. DOI: 10.1039/cs9861500261.
   Web of Science ®Google Scholar
  (b) Fossy, J.; Lefort, D.; Sorba, J. Free Radicals in Organic Chemistry; John Wiley and Sons: Chichester, 1995; Vol. 14, pp 166–180.
   Google Scholar
  (c) Bowman, W. R.; Storey, J. M. D. Synthesis Using Aromatic Homolytic Substitution-Recent Advances. Chem. Soc. Rev. 2007, 36, 1803–1822. DOI: 10.1039/b605183a.
   PubMed Web of Science ®Google Scholar
• (a) Ni, C.; Zhu, L.; Hu, J. Advances in Transition-Metal-Mediated Di-and Monofluoroalkylations. Acta Chim. Sinica 2015, 73, 90–115. DOI: 10.6023/A14110758.
   Web of Science ®Google Scholar
  (b) Caillot, G.; Dufour, J.; Belhomme, M.-C.; Poisson, T.; Grimaud, L.; Pannecoucke, X.; Gillaizeau, I. Copper-Catalyzed Olefinic C-H Difluoroacetylation of Enamides. Chem. Commun. 2014, 50, 5887–5890. DOI: 10.1039/c4cc01994f.
   PubMed Web of Science ®Google Scholar
  (c) Xie, J.; Li, J.; Wurm, T.; Weingand, V.; Sung, H.-L.; Rominger, F.; Rudolph, M.; Hashmi, A. S. K. A General Photoinduced Electron Transfer-Directed Chemoselective Perfluoroalkylation of N,N-Dialkylhydrazones. Org. Chem. Front. 2016, 3, 841–845. DOI: 10.1039/C6QO00158K.
   Web of Science ®Google Scholar
  (d) Prieto, A.; Melot, R.; Bouyssi, D.; Monteiro, N. Palladium-Catalyzed C(sp(2))-H Alkylation of Aldehyde-Derived Hydrazones with Functionalized Difluoromethyl Bromides. Angew. Chem. Int. Ed. Engl. 2016, 55, 1885–1889. DOI: 10.1002/anie.201510334.
   PubMed Web of Science ®Google Scholar
  (e) Prieto, A.; Melot, R.; Bouyssi, D.; Monteiro, N. C–H Difluoroalkylation of Aldehyde Hydrazones with Functionalized Difluoromethyl Bromides under Copper Catalysis. ACS Catal. 2016, 6, 1093–1096. DOI: 10.1021/acscatal.5b02755.
   Web of Science ®Google Scholar
  (f) Zhong, J.-J.; Yang, C.; Chang, X.-Y.; Zou, C.; Lu, W.; Che, C.-M. Platinum(ii) Photo-Catalysis for Highly Selective Difluoroalkylation Reactions. Chem. Commun. 2017, 53, 8948–8951. DOI: 10.1039/c7cc03823b.
   PubMed Web of Science ®Google Scholar
  (g) Sherwood, T. C.; Xiao, H.-Y.; Bhaskar, R. G.; Simmons, E. M.; Zaretsky, S.; Rauch, M. P.; Knowles, R. R.; Dhar, T. G. M. Decarboxylative Intramolecular Arene Alkylation Using N-(Acyloxy)Phthalimides, an Organic Photocatalyst, and Visible Light. J. Org. Chem. 2019, 84, 8360–8379. DOI: 10.1021/acs.joc.9b00432.
   PubMed Web of Science ®Google Scholar
• (a) Murakami, S.; Kim, S.; Ishii, H.; Fuchigami, T. Synlett 2004, 5, 815–818.
   Google Scholar
  (b) Murakami, S.; Ishii, H.; Tajima, T.; Fuchigami, T. Photochemical Substitution of Olefins and Aromatic Compounds with Difluoromethyl Radicals Bearing Ester and Phosphonate Groups. Tetrahedron 2006, 62, 3761–3769. DOI: 10.1016/j.tet.2005.12.057.
   Web of Science ®Google Scholar
  (c) Jung, J.; Kim, E.; You, Y.; Cho, E. J. Visible Light-Induced Aromatic Difluoroalkylation. Adv. Synth. Catal. 2014, 356, 2741–2748. DOI: 10.1002/adsc.201400542.
   Web of Science ®Google Scholar
  (d) Wang, X.; Zhao, S.; Liu, J.; Zhu, D.; Guo, M.; Tang, X.; Wang, G. Copper-Catalyzed C–H Difluoroalkylations and Perfluoroalkylations of Alkenes and (Hetero)Arenes. Org. Lett. 2017, 19, 4187–4190. DOI: 10.1021/acs.orglett.7b01712.
   PubMed Web of Science ®Google Scholar
  (e) Bottecchia, C.; Martín, R.; Abdiaj, I.; Crovini, E.; Alcazar, J.; Orduna, J.; Blesa, M. J.; Carrillo, J. R.; Prieto, P.; Noël, T. De Novo Design of Organic Photocatalysts: Bithiophene Derivatives for the Visible-Light Induced C − H Functionalization of Heteroarenes. Adv. Synth. Catal. 2019, 361, 945–950., DOI: 10.1002/adsc.201801571.
   Web of Science ®Google Scholar
• (a) Fujiwara, Y.; Dixon, J. A.; Rodriguez, R. A.; Baxter, R. D.; Dixon, D. D.; Collins, M. R.; Blackmond, D. G.; Baran, P. S. A New Reagent for Direct Difluoromethylation. J. Am. Chem. Soc. 2012, 134, 1494–1497. DOI: 10.1021/ja211422g.
   PubMed Web of Science ®Google Scholar
  (b) Zhu, S.-Q.; Liu, Y.-L.; Li, H.; Xu, X.-H.; Qing, F.-L. Direct and Regioselective C-H Oxidative Difluoromethylation of Heteroarenes. J. Am. Chem. Soc. 2018, 140, 11613–11617. DOI: 10.1021/jacs.8b08135.
   PubMed Web of Science ®Google Scholar
  (c) Xie, X.; Zhang, Y.; Hao, J.; Wan, W. Ag-Catalyzed Minisci C-H Difluoromethylarylation of N-Heteroarenes. Org. Biomol. Chem. 2020, 18, 400–404. DOI: 10.1039/c9ob02586c.
   PubMed Web of Science ®Google Scholar
  (d) Tung, T. T.; Christensen, S. B.; Nielsen, J. Difluoroacetic Acid as a New Reagent for Direct C-H Difluoromethylation of Heteroaromatic Compounds. Chemistry 2017, 23, 18125–18128. DOI: 10.1002/chem.201704261.
   PubMed Web of Science ®Google Scholar
  (e) Hong, G.; Yuan, J.; Fu, J.; Pan, G.; Wang, Z.; Yang, L.; Xiao, Y.; Mao, P.; Zhang, X. Transition-Metal-Free Decarboxylative C3-Difluoroarylmethylation of Quinoxalin-2(1H)-Ones with α,α-Difluoroarylacetic Acids. Org. Chem. Front. 2019, 6, 1173–1182. DOI: 10.1039/C9QO00105K.
   Web of Science ®Google Scholar
  (f) Proctor, R. S. J.; Phipps, R. J. Recent Advances in Minisci-Type Reactions. Angew. Chem. Int. Ed. Engl. 2019, 58, 13666–13699. DOI: 10.1002/anie.201900977.
   PubMed Web of Science ®Google Scholar
  (g) Zhang, W.; Xiang, X.-X.; Chen, J.; Yang, C.; Pan, Y.-L.; Cheng, J.-P.; Meng, Q.; Li, X. Direct C-H Difluoromethylation of Heterocycles via Organic Photoredox Catalysis. Nat. Commun. 2020, 11, 638. DOI: 10.1038/s41467-020-14494-8.
   PubMed Web of Science ®Google Scholar
• Baykov, S. V.; Boyarskiy, V. P. Metal-Free Functionalization of Azine N-Oxides with Electrophilic Reagents. Chem. Heterocycl. Comp. 2020, 56, 814–823. DOI: 10.1007/s10593-020-02737-x.
   Web of Science ®Google Scholar
• (a) Andersson, H.; Almqvist, F.; Olsson, R. Synthesis of 2-Substituted Pyridines via a Regiospecific Alkylation, Alkynylation, and Arylation of Pyridine N-Oxides. Org. Lett. 2007, 9, 1335–1337. DOI: 10.1021/ol070184n.
   PubMed Web of Science ®Google Scholar
  (b) Deng, G.; Ueda, K.; Yanagisawa, S.; Itami, K.; Li, C.-J. Coupling of Nitrogen Heteroaromatics and Alkanes without Transition Metals: A New Oxidative Cross-Coupling at C-H/C-H Bonds. Chemistry 2009, 15, 333–337. DOI: 10.1002/chem.200801893.
   PubMed Web of Science ®Google Scholar
  (c) Bull, J. A.; Mousseau, J. J.; Pelletier, G.; Charette, A. Synthesis of Pyridine and Dihydropyridine Derivatives by Regio- and Stereoselective Addition to N-Activated Pyridines. Chem. Rev. 2012, 112, 2642–2713. DOI: 10.1021/cr200251d.
   PubMed Web of Science ®Google Scholar
  (d) Sun, W.; Xie, Z.; Liu, J.; Wang, L. Oxidative Cross-Coupling of Pyridine N-Oxides and Ethers between C(sp(2))-H/C(sp(3))-H Bonds under Transition-Metal-Free Conditions. Org. Biomol. Chem. 2015, 13, 4596–4604. DOI: 10.1039/c5ob00237k.
   PubMed Web of Science ®Google Scholar
  (e) Beatty, J. W.; Douglas, J. J.; Miller, R.; McAtee, R. C.; Cole, K. P.; Stephenson, C. R. J. Photochemical Perfluoroalkylation with Pyridine N-Oxides: Mechanistic Insights and Performance on a Kilogram Scale. Chemistry 2016, 1, 456–472. DOI: 10.1016/j.chempr.2016.08.002.
   PubMed Web of Science ®Google Scholar
  (f) Zhang, W.-M.; Dai, J.-J.; Xu, J.; Xu, H.-J. Visible-Light-Induced C2 Alkylation of Pyridine N-Oxides. J. Org. Chem. 2017, 82, 2059–2066. DOI: 10.1021/acs.joc.6b02891.
   PubMed Web of Science ®Google Scholar
  (g) Lantaño, B.; Barata-Vallejo, S.; Postigo, A. Organic Dye-Photocatalyzed Fluoroalkylation of heteroarene-N-Oxide Derivatives. Org. Biomol. Chem. 2018, 16, 6718–6727. DOI: 10.1039/c8ob01653d.
   PubMed Web of Science ®Google Scholar
  (h) An, W.; Choi, S. B.; Kim, N.; Kwon, N. Y.; Ghosh, P.; Han, S. H.; Mishra, N. K.; Han, S.; Hong, S.; Kim, I. S. C2-Selective C-H Methylation of Heterocyclic N-Oxides with Sulfonium Ylides. Org. Lett. 2020, 22, 9004–9009. DOI: 10.1021/acs.orglett.0c03403.
   PubMed Web of Science ®Google Scholar
  (i) Liang, C.; Zhuo, W.; Niu, Y.; Gao, G. Synthesis 2020, 52, 219–226.
   Web of Science ®Google Scholar
• a) Yoon, T. P.; Ischay, M. A.; Du, J. Visible Light Photocatalysis as a Greener Approach to Photochemical Synthesis. Nat. Chem. 2010, 2, 527–532. DOI: 10.1038/nchem.687.
   PubMed Web of Science ®Google Scholar
  (b) Prier, C. K.; Rankic, D. A.; MacMillan, D. W. C. Visible Light Photoredox Catalysis with Transition Metal Complexes: applications in Organic Synthesis. Chem. Rev. 2013, 113, 5322–5363. DOI: 10.1021/cr300503r.
   PubMed Web of Science ®Google Scholar
  (c) Ma, G.; Wan, W.; Li, J.; Hu, Q.; Jiang, H.; Zhu, S.; Wang, J.; Hao, J. An Efficient Regioselective Hydrodifluoromethylation of Unactivated Alkenes with TMSCF₂CO₂Et at Ambient Temperature. Chem. Commun. 2014, 50, 9749–9752. DOI: 10.1039/c4cc04591b.
   PubMed Web of Science ®Google Scholar
  (d) Wang, X.; Wan, W.; Chen, Y.; Li, J.; Jiang, H.; Wang, Y.; Deng, H.; Hao, J. Ag I -Promoted Cascade for Difluoromethylation of Activated Alkenes to Difluoromethylated Oxindoles. Eur. J. Org. Chem. 2016, 2016, 3773–3779. DOI: 10.1002/ejoc.201600461.
   Web of Science ®Google Scholar
  (e) Romero, N. A.; Nicewicz, D. A. Organic Photoredox Catalysis. Chem. Rev. 2016, 116, 10075–10166. DOI: 10.1021/acs.chemrev.6b00057.
   PubMed Web of Science ®Google Scholar
  (f) Wan, W.; Ma, G.; Li, J.; Chen, Y.; Hu, Q.; Li, M.; Jiang, H.; Deng, H.; Hao, J. Silver-Catalyzed Oxidative Decarboxylation of Difluoroacetates: Efficient Access to C-CF2 Bond Formation. Chem. Commun. 2016, 52, 1598–1601. DOI: 10.1039/c5cc09179a.
   PubMed Web of Science ®Google Scholar
  (g) Pan, X.; Xia, H.; Wu, J. Recent Advances in Photoinduced Trifluoromethylation and Difluoroalkylation. Org. Chem. Front. 2016, 3, 1163–1185. DOI: 10.1039/C6QO00153J.
   Web of Science ®Google Scholar
  (h) Lee, J. W.; Lee, K. N.; Ngai, M.-Y. Synthesis of Tri- and Difluoromethoxylated Compounds by Visible-Light Photoredox Catalysis. Angew. Chem. Int. Ed. Engl. 2019, 58, 11171–11181. DOI: 10.1002/anie.201902243.
   PubMed Web of Science ®Google Scholar
  (h) Barata-Vallejo, S.; Postigo, A. Photocatalytic Difluoromethylation Reactions of Aromatic Compounds and Aliphatic Multiple C–C Bonds. Molecules 2019, 24, 4483. DOI: 10.3390/molecules24244483.
   Web of Science ®Google Scholar
  (i) Koike, T.; Akita, M. Org. Biomol. Chem. 2019, 17, 5413–5419. DOI: 10.1039/C9OB00734B.
   PubMed Web of Science ®Google Scholar
  (j) Zhao, H.; Ma, G.; Xie, X.; Wang, Y.; Hao, J.; Wan, W. Pd(ii)-Catalyzed Decarboxylative Meta-C-H Difluoromethylation. Chem. Commun. 2019, 55, 3927–3930. DOI: 10.1039/c9cc00984a.
   PubMed Web of Science ®Google Scholar
  (k) Chen, F.; Xu, X.-H.; Qing, F.-L. Photoredox-Catalyzed Addition of Dibromofluoromethane to Alkenes: Direct Synthesis of 1-Bromo-1-Fluoroalkanes. Org. Lett. 2021, 23, 2364–2369. DOI: 10.1021/acs.orglett.1c00639.
   PubMed Web of Science ®Google Scholar
  (l) Wang, Q.; Gong, H.; Zhang, Y.; Peng, Y.; Chen, H.; Li, M.; Deng, H.; Hao, J.; Wan, W. Visible-Light Mediated Stereospecific C(sp 2)–H Difluoroalkylation of (Z)-Aldoximes. Org. Biomol. Chem. 2021, 19, 7867–7874. DOI: 10.1039/D1OB01401C.
   PubMed Web of Science ®Google Scholar
  (m) Bortolato, T.; Cuadros, S.; Simionato, G.; Dell'Amico, L. The Advent and Development of Organophotoredox Catalysis. Chem. Commun. 2022, 58, 1263–1283., DOI: 10.1039/d1cc05850a.
   PubMed Web of Science ®Google Scholar
  (n) Holmberg-Douglas, N.; Nicewicz, D. A. Photoredox-Catalyzed C-H Functionalization Reactions. Chem. Rev. 2022, 122, 1925–2016. DOI: 10.1021/acs.chemrev.1c00311.
   PubMed Web of Science ®Google Scholar
• Hou, C.; Sun, S.; Liu, Z.; Zhang, H.; Liu, Y.; An, Q.; Zhao, J.; Ma, J.; Sun, Z.; Chu, W. Visible-Light-Induced Decarboxylative Acylation of Pyridine N-Oxides with α-Oxocarboxylic Acids Using Fluorescein Dimethylammonium as a Photocatalyst. Adv. Synth. Catal. 2021, 363, 2806–2812. DOI: 10.1002/adsc.202100168.
   Web of Science ®Google Scholar
• (a) Wang, L.; Wei, X.-J.; Jia, W.-L.; Zhong, J.-J.; Wu, L.-Z.; Liu, Q. Visible-Light-Driven Difluoroacetamidation of Unactive Arenes and Heteroarenes by Direct C-H Functionalization at Room Temperature. Org. Lett. 2014, 16, 5842–5845. DOI: 10.1021/ol502676y.
   PubMed Web of Science ®Google Scholar
  (b) Zhang, Z.; Tang, X.; Dolbier, W. R. Photoredox-Catalyzed Tandem Insertion/Cyclization Reactions of Difluoromethyl and 1,1-Difluoroalkyl Radicals with Biphenyl Isocyanides. Org. Lett. 2015, 17, 4401–4403. DOI: 10.1021/acs.orglett.5b02061.
   PubMed Web of Science ®Google Scholar
  (c) Xu, P.; Wang, G.; Zhu, Y.; Li, W.; Cheng, Y.; Li, S.; Zhu, C. Visible-Light Photoredox-Catalyzed C-H Difluoroalkylation of Hydrazones through an Aminyl Radical/Polar Mechanism. Angew. Chem. Int. Ed. Engl. 2016, 55, 2939–2943. DOI: 10.1002/anie.201508698.
   PubMed Web of Science ®Google Scholar
  (d) Wei, X.-J.; Boon, W.; Hessel, V.; Noël, T. Visible-Light Photocatalytic Decarboxylation of α,β-Unsaturated Carboxylic Acids: Facile Access to Stereoselective Difluoromethylated Styrenes in Batch and Flow. ACS Catal. 2017, 7, 7136–7140. DOI: 10.1021/acscatal.7b03019.
   PubMed Web of Science ®Google Scholar
  (e) Lee, D. S.; Hwang, H. S.; Cho, E. J. Visible-Light-Promoted Synthesis of Fluoroalkylated Oximes. Chem. Asian J. 2018, 13, 2405–2409. DOI: 10.1002/asia.201800524.
   PubMed Web of Science ®Google Scholar
  (f) Patra, T.; Mukherjee, S.; Ma, J.; Strieth-Kalthoff, F.; Glorius, F. Visible-Light-Photosensitized Aryl and Alkyl Decarboxylative Functionalization Reactions. Angew. Chem. Int. Ed. Engl. 2019, 58, 10514–10520. DOI: 10.1002/anie.201904671.
   PubMed Web of Science ®Google Scholar
  (g) Zhang, J.; Kohlbouni, S. T.; Borhan, B. Cu-Catalyzed Oxidation of C2 and C3 Alkyl-Substituted Indole via Acyl Nitroso Reagents. Org. Lett. 2019, 21, 14–17. DOI: 10.1021/acs.orglett.8b03185.
   PubMed Web of Science ®Google Scholar
• (a) Wang, D.; Liu, Z.; Wang, Z.; Ma, X.; Yu, P. Metal- and Base-Free Regioselective Thiolation of the Methyl C(sp 3)–H Bond in 2-Picoline N-Oxides. Green Chem. 2019, 21, 157–163. DOI: 10.1039/C8GC03072C.
   Web of Science ®Google Scholar
  (b) Chudinov; R, A. A.; Dovbnya, S.; Krasnokutskaya; V, E. A.; Ogorodnikov; I, D.; Filimonova, L. A New Transformation of Aminopyridines upon Diazotization in Acetonitrile with the Formation of N-Pyridinylacetamides. Russ. Chem. Bull. 2016, 65, 2312–2314. DOI: 10.1007/s11172-016-1583-9.
   Web of Science ®Google Scholar
  (c) Caron, S.; Do, N. M.; Sieser, J. E. A Practical, Efficient, and Rapid Method for the Oxidation of Electron Deficient Pyridines Using Trifluoroacetic Anhydride and Hydrogen Peroxide–Urea Complex. Tetrahedron Lett. 2000, 41, 2299–2302. DOI: 10.1016/S0040-4039(00)00165-9.
   Web of Science ®Google Scholar
• Morimoto, H.; Fujiwara, R.; Shimizu, Y.; Morisaki, K.; Ohshima, T. Lanthanum(III) Triflate Catalyzed Direct Amidation of Esters. Org Lett. 2014, 16, 2018–2021. DOI: 10.1021/ol500593v.
   PubMed Web of Science ®Google Scholar