Cobalt (II)-catalyzed direct C3-selective C–H acyloxylation of indoles with tert-butyl peresters

References

• For recent selected reviews, see: (a) Arockiam, P. B.; Bruneau, C.; Dixneuf, P. H. Ruthenium(II)-Catalyzed C–H Bond Activation and Functionalization. Chem. Rev. 2012, 112, 5879–5918. (b) Li, B.-J.; Shi, Z.-J. From C(sp2)-H to C(sp3)-H: Systematic Studies on Transition Metal-Catalyzed Oxidative C–C Formation. Chem. Soc. Rev. 2012, 41, 5588–5598. (c) Girard, S. A.; Knauber, T.; Li, C.-J. The Cross-Dehydrogenative Coupling of C(sp3)-H Bonds: A Versatile Strategy for C–C Bond Formations. Angew. Chem. Int. Ed. Engl. 2014, 53, 74–100. (d) Zhang, F.; Spring, D. R. Arene C–H Functionalisation Using a Removable/Modifiable or a Traceless Directing Group Strategy. Chem. Soc. Rev. 2014, 43, 6906–6919. (e) Ackermann, L. Carboxylate-Assisted Ruthenium-Catalyzed Alkyne Annulations by C–H/Het-H Bond Functionalizations. Acc. Chem. Res. 2014, 47, 281–295. (f) Zhang, M.; Zhang, Y.; Jie, X.; Zhao, H.; Li, G.; Su, W. Recent Advances in Directed C–H Functionalizations Using Monodentate Nitrogen-Based Directing Groups. Org. Chem. Front. 2014, 1, 843–895. (g) Topczewski, J. J.; Sanford, M. S. Carbon-Hydrogen (C–H) Bond Activation at PdIV: A Frontier in C–H Functionalization Catalysis Chem. Sci. 2015, 6, 70–76. (h) Chen, Z.; Wang, B.; Zhang, J.; Yu, W.; Liu, Z.; Zhang, Y. Org. Chem. Front. 2015, 2, 1107–1295. (i) Shin, K.; Kim, H.; Chang, S. Transition-Metal-Catalyzed C–N Bond Forming Reactions Using Organic Azides as the Nitrogen Source: A Journey for the Mild and Versatile C–H Amination. Acc. Chem. Res. 2015, 48, 1040–1052. (j) Cheng, C.; Hartwig, J. F. Catalytic Silylation of Unactivated C–H Bonds. Chem. Rev. 2015, 115, 8946–8975. (k) Qiu, G.; Wu, J. Transition Metal-Catalyzed Direct Remote C–H Functionalization of Alkyl Groups via C(sp 3)–H Bond Activation. Org. Chem. Front. 2015, 2, 169–178. (l) Liu, J.; Chen, G.; Tan, Z. Copper-Catalyzed or -Mediated C–H Bond Functionalizations Assisted by Bidentate Directing Groups. Adv. Synth. Catal. 2016, 358, 1174–1194. (m) Gensch, T.; Hopkinson, M. N.; Glorius, F.; Wencel-Delord, J. Mild Metal-Catalyzed C-H Activation: Examples and Concepts. Chem. Soc. Rev. 2016, 45, 2900–2936. (n) Wang, F.; Yu, S.; Li, X. Transition Metal-Catalysed Couplings between Arenes and Strained or Reactive Rings: Combination of C-H Activation and Ring Scission. Chem. Soc. Rev. 2016, 45, 6462–6477. (o) He, J.; Wasa, M.; Chan, K. S. L.; Shao, Q.; Yu, J.-Q. Palladium-Catalyzed Transformations of Alkyl C–H Bonds. Chem. Rev. 2017, 117, 8754–8786. (p) Crabtree, R. H.; Lei, A. Introduction: CH Activation. Chem. Rev. 2017, 117, 8481–8482. (q) Baudoin, O. Ring Construction by Palladium(0)-Catalyzed C(sp3)-H Activation. Acc. Chem. Res. 2017, 50, 1114–1123. (r) Rit, R. K.; Shankar, M.; Sahoo, A. K. C-H Imidation: A Distinct Perspective of C–N Bond Formation. Org. Biomol. Chem. 2017, 15, 1282–1293. (s) Newton, C. G.; Wang, S.-G.; Oliveira, C. C.; Cramer, N. Catalytic Enantioselective Transformations Involving C–H Bond Cleavage by Transition-Metal Complexes. Chem. Rev. 2017, 117, 8908–8976. (t) Bahr, S.; Oestreich, M. Electrophilic Aromatic Substitution with Silicon Electrophiles: Catalytic Friedel-Crafts C-H Silylation. Angew. Chem. Int. Ed. Engl. 2017, 56, 52–59.
   PubMed Web of Science ®Google Scholar
• Cristau, P.; Vors, J.-P.; Zhu, J. Rapid and Diverse Route to Natural Product-like Biaryl Ether Containing Macrocycles. Tetrahedron 2003, 59, 7859–7870. (b) Brasholz, M.; Sörgel, S.; Azap, C.; Reißig, H.-U. Rubromycins: Structurally Intriguing, Biologically Valuable, Synthetically Challenging Antitumour Antibiotics. Eur. J. Org. Chem. 2007, 2007, 3801–3814. (c) Kurume, A.; Kamata, Y.; Yamashita, M.; Wang, Q.; Matsuda, H.; Yoshikawa, M.; Kawasaki, I.; Ohta, S. Synthesis of 3-Substituted Isocoumarins and Their Inhibitory Effects on Degranulation of RBL-2H3 Cells Induced by Antigen. Chem. Pharm. Bull. 2008, 56, 1264–1269. (d) Wang, S.; Beck, R.; Blench, T.; Burd, A.; Buxton, S.; Malic, M.; Ayele, T.; Shaikh, S.; Chahwala, S.; Chander, C.; et al. Studies of Benzothiophene Template as Potent Factor IXa (FIXa) Inhibitors in Thrombosis. J. Med. Chem. 2010, 53, 1465–1472. (e) Roughley, S. D.; Jordan, A. M. The Medicinal Chemist's Toolbox: An Analysis of Reactions Used in the Pursuit of Drug Candidates. J. Med. Chem. 2011, 54, 3451–3479. (f) Imramovsky, A.; Jorda, R.; Pauk, K.; Reznickova, E.; Dusek, J.; Hanusek, J.; Krystof, V. Substituted 2-Hydroxy-N-(Arylalkyl)Benzamides Induce Apoptosis in Cancer Cell Lines. Eur. J. Med. Chem. 2013, 68, 253–259. (g) Ola, A. R. B.; Thomy, D.; Lai, D.; Brötz-Oesterhelt, H.; Proksch, P. Inducing Secondary Metabolite Production by the Endophytic Fungus Fusarium Tricinctum through Coculture with Bacillus subtilis. J. Nat. Prod. 2013, 76, 2094–2099. doi:10.1016/j.tet.2003.08.031
   Web of Science ®Google Scholar
• Dick, A. R.; Hull, K. L.; Sanford, M. S. A Highly Selective Catalytic Method for the Oxidative Functionalization of C-H Bonds. J. Am. Chem. Soc. 2004, 126, 2300–2301. (b) Desai, L. V.; Hull, K. L.; Sanford, M. S. Palladium-Catalyzed Oxygenation of Unactivated sp3 C-H Bonds. J. Am. Chem. Soc. 2004, 126, 9542–9543. (c) Kalyani, D.; Sanford, M. S. Regioselectivity in Palladium-Catalyzed C–H Activation/Oxygenation Reactions. Org. Lett. 2005, 7, 4149–4152. doi:10.1021/ja031543m
   PubMed Web of Science ®Google Scholar
• For recent selected examples, see: (a) Desai, L. V.; Stowers, K. J.; Sanford, M. S. Insights into Directing Group Ability in Palladium-Catalyzed C–H Bond Functionalization. J. Am. Chem. Soc. 2008, 130, 13285–13293. (b) Zhang, Y.-H.; Yu, J.-Q. Pd(II)-Catalyzed Hydroxylation of Arenes with 1 Atm of O(2) or Air. J. Am. Chem. Soc. 2009, 131, 14654–14655. (c) Emmert, M. H.; Gary, J. B.; Villalobos, J. M.; Sanford, M. S. Platinum and Palladium Complexes Containing Cationic Ligands as Catalysts for Arene H/D Exchange and Oxidation. Angew. Chem. Int. Ed. Engl. 2010, 49, 5884–5886. (d) Emmert, M. H.; Cook, A. K.; Xie, Y. J.; Sanford, M. S. Back Cover: Remarkably High Reactivity of Pd(OAc)2/Pyridine Catalysts: Nondirected C–H Oxygenation of Arenes (Angew. Chem. Int. Ed. 40/2011). Angew. Chem. Int. Ed. 2011, 50, 9508–9508. (e) Liu, Q.; Li, G.; Yi, H.; Wu, P.; Liu, J.; Lei, A. Pd-Catalyzed Direct and Selective C–H Functionalization: C3-Acetoxylation of Indoles. Chemistry 2011, 17, 2353–2357. (f) Ren, Z.; Mo, F.; Dong, G. Catalytic Functionalization of Unactivated sp3 C–H Bonds via Exo-Directing Groups: Synthesis of Chemically Differentiated 1,2-Diols. J. Am. Chem. Soc. 2012, 134, 16991–16994. (g) Dai, H.-X.; Yu, J.-Q. Pd-Catalyzed Oxidative ortho-C-H Borylation of Arenes. J. Am. Chem. Soc. 2012, 134, 134–137. (h) Gary, J. B.; Cook, A. K.; Sanford, M. S. Palladium Catalysts Containing Pyridinium-Substituted Pyridine Ligands for the C–H Oxygenation of Benzene with K 2 S 2 O 8. ACS Catal. 2013, 3, 700–703. (i) Yang, G.; Lindovska, P.; Zhu, D.; Kim, J.; Wang, P.; Tang, R.-Y.; Movassaghi, M.; Yu, J.-Q. Pd(II)-Catalyzed Meta-C–H Olefination, Arylation, and Acetoxylation of Indolines Using a U-Shaped Template. J. Am. Chem. Soc. 2014, 136, 10807–10813. (j) Hazra, C. K.; Dherbassy, Q.; Wencel-Delord, J.; Colobert, F. Synthesis of Axially Chiral Biaryls through Sulfoxide-Directed Asymmetric Mild C–H Activation and Dynamic Kinetic Resolution. Angew. Chem. Int. Ed. Engl. 2014, 53, 13871–13875. (k) Cook, A. K.; Sanford, M. S. Mechanism of the Palladium-Catalyzed Arene C–H Acetoxylation: A Comparison of Catalysts and Ligand Effects. J. Am. Chem. Soc. 2015, 137, 3109–3118. (l) Liu, B.; Huang, X.; Wang, X.; Ge, Z.; Li, R. Palladium Catalyzed Amide-Oxazoline Directed C–H Acetoxylation of Arenes. Org. Chem. Front. 2015, 2, 797–800. (m) Sarkar, D.; Gulevich, A. V.; Melkonyan, F. S.; Gevorgyan, V. ACS Catal. 2015, 5, 6792–6801. (n) Maji, A.; Bhaskararao, B.; Singha, S.; Sunoj, R. B.; Maiti, D. Chem. Sci. 2016, 7, 3147−3153. (o) Li, S.; Cai, L.; Ji, H.; Yang, L.; Li, G. Nat. Commun. 2016, 7, 10443. doi:10.1021/ja8045519
   PubMedGoogle Scholar
• (a) Ye, Z. S.; Wang, W. H.; Luo, F.; Zhang, S. H.; Cheng, J. Rhodium-Catalyzed Ortho-Benzoxylation of sp(2) C–H Bond. Org. Lett. 2009, 11, 3974–3977. (b) Pham, M. V.; Cramer, N. Rhodium(III)/Copper(II)-Promoted Trans-Selective Heteroaryl Acyloxylation of Alkynes: Stereodefined Access to Trans-Enol Esters. Angew. Chem. Int. Ed. Engl. 2014, 53, 14575–14579. (c) Yu, W.; Chen, J.; Gao, K.; Liu, Z.; Zhang, Y. Amide-Assisted Acetoxylation of Vinyl C(sp2)-H Bonds by Rhodium Catalysis. Org. Lett. 2014, 16, 4870–4873. (d) Wu, Y.; Zhou, B. Rhodium(III)-Catalyzed Selective C–H Acetoxylation and Hydroxylation Reactions. Org. Lett. 2017, 19, 3532–3535. (e) Chen, C.; Pan, Y.; Zhao, H.; Xu, X.; Xu, J.; Zhang, Z.; Xi, S.; Xu, L.; Li, H. A Versatile Rhodium (iii) Catalyst for Direct Acyloxylation of Aryl and Alkenyl C–H Bonds with Carboxylic Acids. Org. Chem. Front. 2018, 5, 415–422. doi:10.1021/ol901609t
   PubMed Web of Science ®Google Scholar
• Raghuvanshi, K.; Rauch, K.; Ackermann, L. Ruthenium(II)-Catalyzed C–H Acyloxylation of Phenols with Removable Auxiliary. Chemistry 2015, 21, 1790–1794. (b) Raghuvanshi, K.; Zell, D.; Ackermann, L. Ruthenium(II)-Catalyzed C–H Oxygenations of Reusable Sulfoximine Benzamides. Org. Lett. 2017, 19, 1278–1281. (c) Padala, K.; Jeganmohan, M. Ruthenium-Catalyzed Oxidative Ortho-Benzoxylation of Acetanilides with Aromatic Acids. Chem. Commun. (Camb.) 2013, 49, 9651–9653. (d) Padala, K.; Jeganmohan, M. Ortho-Benzoxylation of N-Alkyl Benzamides with Aromatic Acids Catalyzed by Ruthenium(II) Complex. Chemistry 2014, 20, 4092–4097. (e) Okada, T.; Nobushige, K.; Satoh, T.; Miura, M. Ruthenium-Catalyzed Regioselective C-H Bond Acetoxylation on Carbazole and Indole Frameworks. Org. Lett. 2016, 18, 1150–1153. doi:10.1002/chem.201405071
   PubMed Web of Science ®Google Scholar
• Vinayak, B.; NavyaSree, P.; Chandrasekharam, M. Iron(iii)-Catalyzed Chelation Assisted Remote C-H Bond Oxygenation of 8-Amidoquinolines. Org. Biomol. Chem. 2017, 15, 9200–9208. (b) Wang, L.; Li, H.; Wang, L. Iron-Catalyzed C(sp3)-H Acyloxylation of Aryl-2 H Azirines with Hypervalent Iodine(III) Reagents. Org. Lett. 2018, 20, 1663–1666. (c) Chiranjeevi, B.; Vinayak, B.; Parsharamulu, T.; PhaniBabu, V. S.; Jagadeesh, B.; Sridhar, B.; Chandrasekharam, M. Iron(III)-Catalyzed C-H Functionalization: Ortho-Benzoyloxylation of N, N -Dialkylanilines and Its Application to 1,4-Benzoxazepines. Eur. J. Org. Chem. 2014, 2014, 7839–7849. (d) Wang, F.; Hu, Q.; Shu, C.; Lin, Z.; Min, D.; Shi, T.; Zhang, W. Copper-Catalyzed Direct Acyloxylation of C(sp2)-H Bonds in Aromatic Amides. Org. Lett. 2017, 19, 3636–3639. (e) Pan, Y.; Huang, X.; Liang, X.; Yuan, J.; Ni, Z.; Zhou, Y. Aerobic Copper Catalyzed α-Oxyacylation of Ketones with Carboxylic Acids. Org. Chem. Front. 2017, 4, 163–169. doi:10.1039/C7OB02159C
   PubMed Web of Science ®Google Scholar
• (a) Ueno, R.; Natsui, S.; Chatani, N. Cobalt(II)-Catalyzed Acyloxylation of C–H Bonds in Aromatic Amides with Carboxylic Acids. Org. Lett. 2018, 20, 1062–1065. (b) Lin, C.; Chen, Z.; Liu, Z.; Zhang, Y. Direct Ortho-Acyloxylation of Arenes and Alkenes by Cobalt Catalysis. Adv. Synth. Catal. 2018, 360, 519–532. (c) Zhang, M.; Ruzi, R.; Li, N.; Xie, J.; Zhu, C. Photoredox and Cobalt co-Catalyzed C(sp 2)–H Functionalization/C–O Bond Formation for Synthesis of Lactones under Oxidant- and Acceptor-Free Conditions. Org. Chem. Front. 2018, 5, 749–752. doi:10.1021/acs.orglett.7b04020
   PubMed Web of Science ®Google Scholar
• For recent reviews on Co-catalyzed C–H functionalization, see: (a) Yoshikai, N. Bull. Chem. Soc. Jpn. 2014, 87, 843–857. (b) Moselage, M.; Li, J.; Ackermann, L. Cobalt-Catalyzed C–H Activation. ACS Catal. 2016, 6, 498–525. (c) Yoshino, T.; Matsunaga, S. Adv. Synth. Catal. 2017, 359, 1245−1262. (d) Wang, S.; Chen, S.-Y.; Yu, X.-Q. C–H Functionalization by High-Valent Cp*Co(iii) Catalysis. Chem. Commun. (Camb.) 2017, 53, 3165–3180.
   Web of Science ®Google Scholar
• For selected recent reviews, see: (a) Ishikura, M.; Abe, T.; Choshi, T.; Hibino, S. Simple Indole Alkaloids and Those with a Non-Rearranged Monoterpenoid Unit. Nat. Prod. Rep. 2013, 30, 694–752. (b) Zhang, M.-Z.; Chen, Q.; Yang, G.-F. A Review on Recent Developments of Indole-Containing Antiviral Agents. Eur. J. Med. Chem. 2015, 89, 421–441. (c) Gu, L. J.; Wang, Y. S.; Zhang, H. T.; Tang, H. J.; Li, G. P.; Yuan, M. L. Palladium-Catalyzed Carbonylation of Indoles Using Aryl Formates as Bifunctional Reagents: A Route to Indol-3-yl Aryl Ketones. ChemCatChem 2016, 8, 2206–2209.
   PubMed Web of Science ®Google Scholar
• (a) Arnold, R. D.; Nutter, W. M.; Stepp, W. L. Notes. Indoxyl Acetate from Indole. J. Org. Chem. 1959, 24, 117–118. (b) Alex, K.; Schwarz, N.; Khedkar, V.; Sayyed, I. A.; Tillack, A.; Michalik, D.; Holenz, J.; Diaz, J. L.; Beller, M. Synthesis of 3-(2-N,N-Diethylaminoethoxy)Indoles as Potential 5-HT6 Receptor Ligands. Org. Biomol. Chem. 2008, 6, 1802–1807. doi:10.1021/jo01083a610
   Web of Science ®Google Scholar
• (a) Choy, P. Y.; Lau, C. P.; Kwong, F. Y. Palladium-Catalyzed Direct and Regioselective C–H Bond Functionalization/Oxidative Acetoxylation of Indoles. J. Org. Chem. 2011, 76, 80–84. (b) Mutule, I.; Suna, E.; Olofsson, K.; Pelcman, B. Catalytic Direct Acetoxylation of Indoles. J. Org. Chem. 2009, 74, 7195–7198. (c) Lubriks, D.; Sokolovs, I.; Suna, E. Iodonium Salts Are Key Intermediates in Pd-Catalyzed Acetoxylation of Pyrroles. Org. Lett. 2011, 13, 4324–4327. (d) Soni, V.; Patel, U. N.; Punji, B. Metal-Free Regioselective C-3 Acetoxylation of N-Substituted Indoles: Crucial Impact of Nitrogen-Substituent. RSC Adv. 2015, 5, 57472–57481. doi:10.1021/jo101584k
   PubMed Web of Science ®Google Scholar
• (a) Wang, X.; Lei, B.; Ma, L.; Zhu, L.; Zhang, X.; Zuo, H.; Zhuang, D.; Li, Z. Cobalt-Catalyzed Cross-Dehydrogenative C(sp2)–C(sp3) Coupling of Oxazole/Thiazole with Ether or Cycloalkane. Chem. Asian J. 2017, 12, 2799–2803. (b) Li, Q.; Hu, W.; Hu, R.; Lu, H.; Li, G. Cobalt-Catalyzed Cross-Dehydrogenative Coupling Reaction between Unactivated C(sp2)-H and C(sp3)-H Bonds. Org. Lett. 2017, 19, 4676–4679. doi:10.1002/asia.201701258
   PubMed Web of Science ®Google Scholar