763
Views
17
CrossRef citations to date
0
Altmetric
Original Articles

Pummerer chemistry of benzothiophene S-oxides: Metal-free alkylation and arylation of benzothiophenes

, , &
Pages 669-677 | Received 28 Mar 2019, Accepted 29 Mar 2019, Published online: 01 Jun 2019

References

  • For a review of biologically active benzothiophenes, see: Keri, R. S.; Chand, K.; Budagumpi, S.; Somappa, S. B.; Patil, S. A.; Nagaraja, B. M. An Overview of Benzo[b]thiophene-Based Medicinal Chemistry. Eur. J. Med. Chem. 2017, 138, 1002. DOI: 10.1016/j.ejmech.2017.07.038.
  • (a) Muchmore, D. B. Raloxifene: A Selective Estrogen Receptor Modulator (SERM) with Multiple Target System Effects. Oncologist 2000, 5, 388; (b) Scott, S. A.; Spencer, C. T.; O’Reilly, M. C.; Brown, K. A.; Lavieri, R. L.; Cho, C. H.; Jung, D. I.; Larock, R. C.; Brown, H. A.; Lindsley, C. W. Discovery of Desketoraloxifene Analogues as Inhibitors of Mammalian, Pseudomonas aeruginosa, and NAPE Phospholipase D Enzymes. ACS Chem. Biol. 2015, 10, 421; (c) Pinto, E; Queiroz, M. R. P.; Vale-Silva, L. A.; Oliveira, J. F.; Begouin, A.; Begouin, J.-M.; Kirsch, G. Antifungal Activity of Synthetic Di(hetero)arylamines Based on the Benzo[b]thiophene Moiety. Bioorg. Med. Chem. 2008, 16, 8172; (d) Banerjee, T.; Sharma, S.K.; Kapoor, N.; Dwivedi, V.; Surolia, N.; Surolia, A. Benzothiophene Carboxamide Derivatives as Inhibitors of Plasmodium falciparum Enoyl‐ACP Reductase. IUBMB Life 2011, 63, 1101; (e) Sato, M.; Turner, C. H.; Wang, T.; Adrian, M. D.; Rowley, E.; Bryant, H. U. LY353381.HCl: A Novel Raloxifene Analog with Improved SERM Potency and Efficacy In Vivo. J. Pharmacol. Exp. 1998, 287, 1; (f) Münster, P. N.; Buzdar, A.; Dhingra, K.; Enas, N.; Ni, L.; Major, M.; Melemed, A.; Seidman, A.; Booser, D.; Theriault, R.; Norton, L.; Hudis, C. Phase I Study of a Third-Generation Selective Estrogen Receptor Modulator, LY353381.HCl, in Metastatic Breast Cancer. J. Clin. Oncol. 2001, 19, 2002; (g) von Angerer, E.; Erber, S. 3-Alkyl-2-phenylbenzo[b]thiophenes: Nonsteroidal Estrogen Antagonists with Mammary Tumor Inhibiting Activity. J. Steroid Biochem. Mol. Biol. 1992, 41, 557; (h) Naganagowda, G.; Thamyongkit, P.; Klai-U-dom, R.; Ariyakriangkrai, W.; Luechai, A.; Petsom, A. Synthesis and Biological Activity of Some More Heterocyclic Compounds Containing Benzothiophene Moiety. J. Sulf. Chem. 2011, 32, 235. DOI: 10.1080/17415993.2011.583394.
  • (a) Takimiya, K.; Shinamura, S.; Osaka, I.; Miyazaki, E. Thienoacene‐Based Organic Semiconductors. Adv. Mater. 2011, 23, 4347; (b) Černovská, K.; Svoboda, J.; Stibor, I.; Glogarová, M.; Vaněk, P.; Novotná, V. Ferroelectric Liquid Crystals with a Fused Heterocyclic Core. Ferroelectrics 2000, 241, 231; (c) Aaron, J.-J.; Párkányi, C.; Adenier, A.; Potin, C.; Zajíčková, Z.; Martínez, O. R.; Svoboda, J.; Pihera, P.; Váchal, P. Fluorescence Properties and Dipole Moments of Novel Fused Thienobenzofurans. Solvent and Structural Effects. J. Fluoresc. 2011, 21, 2133; (d) Chen, X.-K.; Zou, L.-Y.; Ren, A.-M.; Fan, J.-X. How Dual Bridging Atoms Tune Structural and Optoelectronic Properties of Ladder-Type Heterotetracenes?—A Theoretical Study. Phys. Chem. Chem. Phys. 2011, 13, 19490; (e) Vektariene, A. Insights into the Mechanism of the Benzoannelated Thieno[3,2-b]furan Halogenation. Importance of HOMO–HOMO Interaction. J. Phys. Chem. A 2013, 117, 8449. DOI: 10.1021/jp402257u.
  • (a) Nakamura, I.; Sato, T.; Yamamoto, Y. Gold-Catalyzed Intramolecular Carbothiolation of Alkynes: Synthesis of 2,3-Disubstituted Benzothiophenes from (Alpha-Alkoxy Alkyl) (Ortho-Alkynyl Phenyl) Sulfides. Angew. Chem. Int. Ed. 2006, 45, 4473; (b) Wu, B.; Yoshikai, N. Recent Developments in Synthetic Methods for Benzo[b]heteroles. Org. Biomol. Chem. 2016, 14, 5402; (c) Dudnik, A. S.; Gevorgyan, V.; In Catalyzed Carbon-Heteroatom Bond Formation; Yudin, A. K., Ed, 317, Wiley-VCH, 2011; (d) Rayner, C. M.; Graham, M. A.; In Science of Synthesis: Benzo[b]thiophenes, Joule, J. A., Thomas, E. J. Eds.; 2001, Vol. 10, p 155.
  • (a) Hartwig, J. F. Evolution of C–H Bond Functionalization from Methane to Methodology. J. Am. Chem. Soc. 2016, 138, 2; (b) 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; (c) Crabtree R. H.; Lei, A. Introduction: CH Activation. Chem. Rev. 2017, 117, 8481. DOI: 10.1021/acs.chemrev.7b00307.
  • For examples, see ref. 4d. Hammann, J. M.; Haas, D.; Knochel, P. Cobalt-catalyzed Negishi cross-coupling reactions of (hetero)arylzinc reagents with primary and secondary alkyl bromides and iodides. Angew. Chem. Int. Ed. Engl. 2015, 54, 4478. DOI: 10.1002/anie.201411960.
  • For example, see; Kamila, S.; Mukherjee, C.; Mondal, S. S.; De, A. Application of Directed Metallation in Synthesis. Part 3: Studies in the Synthesis of (±)-Semivioxanthin and Its Analogues. Tetrahedron 2003, 59, 1339. DOI: 10.1016/S0040-4020(02)01599-5.
  • See ref. 4d Clark, P. D.; Mesher, S. T. Benzylation of Benzo[b]thiophene Using ZnCl2-Modified Montmorillonite Clay. Phosphorus Sulfur Silicon Relat. Elem. 1995, 105, 157. DOI: 10.1080/10426509508042058.
  • For selected examples, see: (a) Chiong, H. A.; Daugulis, O. Palladium-Catalyzed Arylation of Electron-Rich Heterocycles with Aryl Chlorides. Org. Lett. 2007, 9, 1449; (b) Liégault, B.; Lapointe, D.; Caron, L.; Vlassova, A.; Fagnou, K. Establishment of Broadly Applicable Reaction Conditions for the Palladium-Catalyzed Direct Arylation of Heteroatom-Containing Aromatic Compounds. J. Org. Chem. 2009, 74, 1826; (c) Hu, P.; Zhang, M.; Jie, X.; Su, W. Palladium‐Catalyzed Decarboxylative C–H Bond Arylation of Thiophenes. Angew. Chem. Int. Ed. 2012, 51, 227. DOI: 10.1002/anie.201106451.
  • For selected examples, see: (a) Ueda, K.; Yanagisawa, S.; Yamaguchi, J.; Itami, K. A General Catalyst for the β‐Selective C–H Bond Arylation of Thiophenes with Iodoarenes. Angew. Chem. Int. Ed. 2010, 49, 8946; (b) Tang, D.-T. D.; Collins, K. D.; Glorius, F. Completely Regioselective Direct C–H Functionalization of Benzo[b]thiophenes Using a Simple Heterogeneous Catalyst. J. Am. Chem. Soc. 2013, 135, 7450; (c) Colletto, C.; Islam, S.; Juliá-Hernández, F.; Larrosa, I. Room-Temperature Direct β-Arylation of Thiophenes and Benzo[b]thiophenes and Kinetic Evidence for a Heck-type Pathway. J. Am. Chem. Soc. 2016, 138, 1677; (d) Kirchberg, S.; Tani, S.; Ueda, K.; Yamaguchi, J.; Studer, A.; Itami, K. Oxidative Biaryl Coupling of Thiophenes and Thiazoles with Arylboronic Acids through Palladium Catalysis: Otherwise Difficult C4‐Selective C–H Arylation Enabled by Boronic Acids. Angew. Chem. Int. Ed. 2011, 50, 2387. DOI: 10.1002/anie.201007060.
  • (a) Wippich, J.; Schnapperelle, I.; Bach, T. Regioselective Oxidative Pd-Catalysed Coupling of Alkylboronic Acids with Pyridin-2-yl-substituted Heterocycles. Chem. Commun. 2015, 51, 3166; (b) Xia, Y.; Liu, Z.; Feng, S.; Zhang, Y.; Wang. Ir(III)-Catalyzed Aromatic C–H Bond Functionalization via Metal Carbene Migratory Insertion. J. Org. Chem. 2015, 80, 223. DOI: 10.1021/jo5023102.
  • (a) Nakamura, I.; Siriwardana, A. I.; Saito, S.; Yamamoto, Y. Addition of Heteroaromatics to Alkylidenecyclopropanes Catalyzed by Palladium. J. Org. Chem. 2002, 67, 3445; (b) Mitsudo, K.; Thansandote, P.; Wilhelm, T.; Mariampillai, B.; Lautens, M. Selectively Substituted Thiophenes and Indoles by a Tandem Palladium-Catalyzed Multicomponent Reaction. Org. Lett. 2006, 8, 3939; (c) Vechorkin, O.; Proust, V.; Hu, X. The Nickel/Copper‐Catalyzed Direct Alkylation of Heterocyclic C–H Bonds. Angew. Chem. Int. Ed. 2010, 49, 3061; (d) Sevov, C. S.; Hartwig, J. F. Iridium-Catalyzed Intermolecular Asymmetric Hydroheteroarylation of Bicycloalkenes. J. Am. Chem. Soc. 2013, 135, 2116; (e) Theunissen, C.; Wang, J.; Evano, G. Copper-Catalyzed Direct Alkylation of Heteroarenes. Chem. Sci. 2017, 8, 3465. DOI: 10.1039/c6sc05622a.
  • European Medicines Agency. in ICH Guideline Q3D on Elemental Impurities (London, 2015) http://www.ema.europa.eu/docs/en_GB/document_library/Scientific_guideline/2015/01/WC500180284.pdf.
  • Usluer, Ö.; Abbas, M.; Wantz, G.; Vignau, L.; Hirsch, L.; Grana, E.; Brochon, C.; Cloutet, E.;.; Hadziioannou, G. Metal Residues in Semiconducting Polymers: Impact on the Performance of Organic Electronic Devices. ACS Macro Lett. 2014, 3, 1134. DOI: 10.1021/mz500590d.
  • (a) Yanagi, T.; Otsuka, S.; Kasuga, Y.; Fujimoto, K.; Murakami, K.; Nogi, K.; Yorimitsu, H.; Osuka A. Metal-Free Approach to Biaryls from Phenols and Aryl Sulfoxides by Temporarily Sulfur-Tethered Regioselective C–H/C–H Coupling. J. Am. Chem. Soc. 2016, 138, 14582; (b) Yanagi, T.; Nogi, K.; Yorimitsu, H. Recent Development of ortho-C–H Functionalization of Aryl Sulfoxides through [3,3] Sigmatropic Rearrangement. Tetrahedron Lett. 2018 59, 2951. DOI: 10.1016/j.tetlet.2018.06.055.
  • (a) Huang, X.; Maulide, N. Sulfoxide-Mediated α-Arylation of Carbonyl Compounds. J. Am. Chem. Soc. 2011, 133, 8510. (b) Huang, X.; Patil, M.; Farés, C.; Thiel, W.; Maulide, N. Sulfur(IV)-Mediated Transformations: From Ylide Transfer to Metal-Free Arylation of Carbonyl Compounds. J. Am. Chem. Soc. 2013, 135, 7312. (c) Peng, B.; Geerdink, D.; Farés, C.; Maulide, N. Chemoselective Intermolecular α‐Arylation of Amides. Angew. Chem. Int. Ed. 2014, 53, 5462. (d) Peng, B.; Huang, X.; Xie, L.-G.; Maulide, N. A Brønsted Acid Catalyzed Redox Arylation. Angew. Chem. Int. Ed. 2014, 53, 8718. (e) Kaiser, D.; Veiros, L. F.; Maulide, N. Brønsted Acid‐Mediated Hydrative Arylation of Unactivated Alkynes. Chem. Eur. J. 2016, 22, 4727. (f) Kaiser, D.; Veiros, L. F.; Maulide, N. Redox‐Neutral Arylations of Vinyl Cation Intermediates. Adv. Synth. Catal. 2017, 359, 64.
  • (a) Eberhart, A. J.; Cicoira, C.; Procter, D. J. Nucleophilic ortho-Allylation of Pyrroles and Pyrazoles: An Accelerated Pummerer/Thio-Claisen Rearrangement Sequence. Org. Lett. 2013, 15, 3994. (b) Eberhart, A. J.; Imbriglio, J. E.; Procter, D. J. Nucleophilic Ortho Allylation of Aryl and Heteroaryl Sulfoxides. Org. Lett. 2011, 13, 5882. (c) Eberhart, A. J.; Procter, D. J. Nucleophilic ortho‐Propargylation of Aryl Sulfoxides: An Interrupted Pummerer/Allenyl Thio‐Claisen Rearrangement Sequence. Angew. Chem. Int. Ed. 2013, 52, 4008. (d) Eberhart, A. J.; Shrives, H. J.; Álvarez, E.; Carrër, A.; Zhang, Y.; Procter, D. J. Sulfoxide‐Directed Metal‐Free ortho‐Propargylation of Aromatics and Heteroaromatics. Chem. Eur. J. 2015, 21, 7428. (e) Eberhart, A. J.; Shrives, H.; Zhang, Y.; Carrër, A.; Tate, D. J.; Turner, M. L.; Procter, D. J. Sulfoxide-directed Metal-free Cross-couplings in the Expedient Synthesis of Benzothiophene-based Components of Materials. Chem. Sci. 2016, 7, 1281. (f) Fernández-Salas, J. A.; Eberhart, A. J.; Procter, D. J. Metal-Free CH–CH-Type Cross-Coupling of Arenes and Alkynes Directed by a Multifunctional Sulfoxide Group. J. Am. Chem. Soc. 2016, 138, 790.
  • (a) Hu, L.; Gui, Q.; Chen, X.; Tan, Z.; Zhu, G. HOTf-Catalyzed, Solvent-Free Oxyarylation of Ynol Ethers and Thioethers. J. Org. Chem. 2016, 81, 4861. (b) Akai, S.; Kawashita, N.; Satoh, H.; Wada, Y.; Kakiguchi, K.; Kuriwaki, I.; Kita, Y. Highly Regioselective Nucleophilic Carbon−Carbon Bond Formation on Furans and Thiophenes Initiated by Pummerer-Type Reaction. Org. Lett. 2004, 6, 3793. DOI: 10.1021/ol0484310.
  • For relevant reviews, see: (a) Pulis, A. P.; Procter, D. J. C−H Coupling Reactions Directed by Sulfoxides: Teaching an Old Functional Group New Tricks. Angew. Chem. Int. Ed. 2016, 55, 9842. (b) Yorimitsu, H. Cascades of Interrupted Pummerer Reaction‐Sigmatropic Rearrangement. Chem. Rec. 2017, 17, 1156.
  • For related reactions of other sulfoxides used in ortho C-H arylation, see: (a) Kobatake, T.; Fujino, D.; Yoshida, S.; Yorimitsu, H.; Oshima, K. Synthesis of 3-Trifluoromethylbenzo[b]furans from Phenols via Direct Ortho Functionalization by Extended Pummerer Reaction. J. Am. Chem. Soc. 2010, 132, 11838. (b) Murakami, K.; Yorimitsu, H.; Osuka, A. Practical, Modular, and General Synthesis of Benzofurans through Extended Pummerer Annulation/Cross‐Coupling Strategy. Angew. Chem., Int. Ed. 2014, 53, 7510.
  • For other related reactions involving sulfonium intermediates, see: (a) Kobatake, T.; Yoshida, S.; Yorimitsu, H.; Oshima, K. Reaction of 2‐(2,2,2‐Trifluoroethylidene)‐1,3‐dithiane 1‐Oxide with Ketones under Pummerer Conditions and Its Application to the Synthesis of 3‐Trifluoromethyl‐Substituted Five‐Membered Heteroarenes. Angew. Chem. Int. Ed. 2010, 49, 2340. (b) Yoshida, S.; Yorimitsu, H.; Oshima, K. 2-(2,2,2-Trifluoroethylidene)-1,3-dithiane Monoxide as a Trifluoromethylketene Equivalent. Org. Lett. 2009, 11, 2185. (c) Chen, D. Feng, Q. Yang, Y. Cai, X.-M .Wang, F. Huang, S. Metal-free O–H/C–H Difunctionalization of Phenols by o-hydroxyarylsulfonium Salts in Water. Chem. Sci. 2017, 8, 1601. (d) Hu, G.; Xu, J.; Li, P. Sulfur Mediated Allylic C–H Alkylation of Tri- and Disubstituted Olefins. Org. Lett. 2014, 16, 6036. (e) Tayu, M.; Higuchi, K.; Ishizaki, T.; Kawasaki, T. Thionium-Based One-Pot Construction of Homo-/Heterodimeric Pyrroloindoline from Tryptamine. Org. Lett. 2014, 16, 3613; (f) Fernández-Salas, J. A.; Pulis, A. P.; Procter, D. J. Metal-free C–H Thioarylation of Arenes Using Sulfoxides: A Direct, General Diaryl Sulfide Synthesis. Chem. Commun. 2016, 52, 12364. DOI: 10.1039/c6cc07627k.
  • (a) Nakayama, J.; Sugihara, Y. The Chemistry of Thiophene 1-Oxides. Sulfur Rep. 1997, 19, 349. (b) Thiemann, T.; Fujii, H.; Ohira, D.; Arima, K. Lib, Y.; Mataka, S. Cycloaddition of Thiophene S-oxides to Allenes, Alkynes and to Benzyne. New J. Chem. 2003, 27, 1377. (c) Thiemann, T.; Arima, K.; Kumazoe K.; Mataka, S. [3.3]Orthocyclophanes – Study Objects for π-Interaction. Rep. Inst. Adv. Mat. Study Kyushu Univ. 2000, 14, 139.
  • Amoudi, M. E. F. E.; Geneste, P.; Olive, J. L. Photoreactivity of 2- and 3-Substituted Benzo[b]thiophene 1-Oxides in Solution. J. Org. Chem. 1981, 46, 4258. DOI: 10.1021/jo00334a030.
  • Geneste, P.; Durand, R.; Pioch, D. The First 1,3-Dipolar Addition to a Benzothiophene s-Oxide. Tetrahedron Lett 1979, 20, 4845. DOI: 10.1016/S0040-4039(01)86728-9.
  • Bened, A.; Durand, R.; Pioch, D.; Geneste, P.; Guimon, C.; Guillouze, G. P.; Declercq, J.-P.; Germain, G.; Briard, P.; Rambaud, J.; Roques, R. Isoxazolidines by Cycloadditions of N,α-diphenyl Nitrone in the Benzo[b]thiophene S-oxide and SS-dioxide Series. J. Chem. Soc. Perkin Trans. II 1984, 0, 1. DOI: 10.1039/P29840000001.
  • David, E.; Perrin, J.; Pellet-Rostaing, S.; Fournier dit Chabert, J.; Lemaire, M. Efficient Access to 2-aryl-3-Substituted benzo[b]thiophenes. J. Org. Chem. 2005, 70, 3569. DOI: 10.1021/jo0500378.
  • Acheson, R. M.; Stubbs, J. K. The Synthesis of Some Heterocyclic Sulphonium Salts. J. Chem. Soc., Perkin Trans. 1 1972, 0, 899. DOI: 10.1039/p19720000899.
  • Pouzet, P.; Erdelmeier, I.; Dansette, P. M.; Mansuy, D. Synthesis of (4-Chlorophenyl)-(1-Oxo-1λ4-Benzo[b]Thien-2-yl)Methanone and Study of Its Reactivity towards Sulfur- and Oxygen-Containing Nucleophiles. Tetrahedron 1998, 54, 14811. DOI: 10.1016/S0040-4020(98)00929-6.
  • Li, Y.; Thiemann, T.; Sawada, T.; Mataka, S.; Tashiro, M. Lewis Acid Catalysis in the Oxidative Cycloaddition of Thiophenes(1). J. Org. Chem. 1997, 62, 7926.
  • Shrives, H. J.; Fernández-Salas, J.; Hedtke, C.; Pulis, A. P.; Procter, D. J. Regioselective Synthesis of C3 Alkylated and Arylated benzothiophenes. Nat. Commun. 2017, 8, 14801. DOI: 10.1038/ncomms14801.
  • He, Z.; Shrives, H. J.; Fernández-Salas, J. A.; Abengózar, A.; Neufeld, J.; Yang, K.; Pulis, A. P.; Procter, D. J. Synthesis of C2 Substituted Benzothiophenes via an Interrupted Pummerer/[3,3]-Sigmatropic/1,2-Migration Cascade of Benzothiophene S-Oxides. Angew. Chem. Int. Ed. Engl. 2018, 57, 5759. DOI: 10.1002/anie.201801982.
  • For examples, see: (a) Nguyen, Q.; Nguyen, T.; Driver, T. G. Iron(II) Bromide-Catalyzed Intramolecular C–H Bond Amination [1,2]-Shift Tandem Reactions of Aryl Azides. J. Am. Chem. Soc. 2013, 135, 620; (b) López-Alvarado, P.; Caballero, E.; Avendanõ, C.; Menéndez, J. C. Efficient Synthesis of N-Prenylpyrroloindoline and N-Prenylindole Alkaloids Based on a New Four-Reaction Anionic Domino Process. Org. Lett. 2006, 8, 4303.
  • For examples of C3 to C2 1,2-migration in 3,3-disubstitiuted benzothiopheniums, see: (a) Leardini, R.; Tundo, A.; Zanardi, G.; Pedulli, G. Synthesis and Rearrangement of Diaryl-Hydroxy-Benzo[b]Thiophens. A New Synthesis of 2,3-Diaryl-Benzo[b]Thiophens. Tetrahedron Lett. 1983, 24, 3381. (b) Yong, K.; Salim, M.; Capretta, A. Intramolecular Carbenoid Insertions: Reactions of α-Diazo Ketones Derived from Furanyl-, Thienyl-, (Benzofuranyl)-, and (Benzothienyl)Acetic Acids with Rhodium(II) Acetate. J. Org. Chem. 1998, 63, 9828. DOI: 10.1021/jo9814593.
  • Kitamura, T.; Zhang, B.-X.; Fujiwara, Y. Novel [4 + 2]-Cycloaddition of 1-phenyl-1-benzothiophenium Salts with Dienes. Experimental Evidence for a Lack of Aromaticity in the Thiophene Ring. J. Org. Chem. 2003, 68, 731. DOI: 10.1021/jo020406p.
  • Huang, X.; Klimczyk, S.; Maulide, N. Charge-Accelerated Sulfonium [3,3]-Sigmatropic Rearrangements. Synthesis 2012, 44, 175. DOI: 10.1055/s-0031-1289632.
  • When thioacetal 13 (R = H) is treated with BF3·OEt2, mixtures of C3 and C2 arylated products are formed in 57:43 ratio respectively, as a result- of competing aromatization and 1,2-migration in II-A, in a combined yield of 93%.
  • Hare, S. R.; Li, A.; Tantillo, D. J. Post-Transition State Bifurcations Induce Dynamical Detours in Pummerer-like Reactions. Chem. Sci. 2018, 9, 8937. DOI: 10.1039/c8sc02653j.
  • For recent reviews on this topic see: (a) Ess, D. H.; Wheeler, S. E.; Iafe, R. G.; Xu, L.; Çelebi‐Ölçüm N.; Houk K. N. Bifurcations on Potential Energy Surfaces of Organic Reactions. Angew. Chem. Int. Ed. 2008, 47, 7592; (b) Rehbein, J.; Carpenter B. K. Do We Fully Understand What Controls Chemical Selectivity? Phys. Chem. Chem. Phys. 2011, 13, 20906; (c) Hare, A. R.; Tantillo, D. J. Post-transition State Bifurcations Gain Momentum – Current State of the Field. Pure Appl. Chem. 2017, 89, 679. DOI: 10.1515/pac-2017-0104.
  • For examples of biologically active benzoxepines, see: (a) Wijnberg, J. B. P. A.; van Veldhuizen, A.; Swarts, H. J.; Frankland, J. C.; Field, J. A. Novel Monochlorinated Metabolites with a 1-benzoxepin Skeleton from Mycena galopus. Tetrahedron Lett. 1999, 40, 5767; (b) Shiraishi, M.; Aramaki, Y.; Seto, M.; Imoto, H.; Nishikawa, Y.; Kanzaki, N.; Okamoto, M.; Sawada, H.; Nishimura, O.; Baba, M.; Fujino, M. Discovery of Novel, Potent, and Selective Small-Molecule CCR5 Antagonists as Anti-HIV-1 Agents:  Synthesis and Biological Evaluation of Anilide Derivatives with a Quaternary Ammonium Moiety. J. Med. Chem. 2000, 43, 2049; (c) Seto, M.; Miyamoto, N.; Aikawa, K.; Aramaki, Y.; Kanzaki, N.; Iizawa, Y.; Baba, M.; Shiraishi, M. Orally Active CCR5 Antagonists as Anti-HIV-1 Agents. Part 3: Synthesis and Biological Activities of 1-benzazepine Derivatives Containing a Sulfoxide Moiety. Bioorg. Med. Chem. 2005, 13, 363.
  • (a) Černovská, K.; Nič, M.; Pihera, P.; Svoboda, J.; A Novel Synthesis of [1]Benzothieno[3,2-b][1]benzofuran. Collect. Czech. Chem. Commun. 2000, 65, 1939; (b) Kaida, H.; Satoh, T.; Hirano, K.; Miura, M. Synthesis of Thieno[3,2-b]benzofurans by Palladium-catalyzed Intramolecular C–H/C–H Coupling. Chem. Lett. 2015, 44, 1125; (c) Saito, K.; Chikkade, P. K.; Kanai, M.; Kuninobu, Y. Palladium-Catalyzed Construction of Heteroatom-Containing π-Conjugated Systems by Intramolecular Oxidative C–H/C–H Coupling Reaction. Chem. Eur. J. 2015, 21, 8365; (d) Wang, M.; Wei, J.; Fan, Q.; Jiang, X. Cu(II)-Catalyzed Sulfide Construction: Both Aryl Groups Utilization of Intermolecular and Intramolecular Diaryliodonium Salt. Chem. Commun. 2017, 53, 2918; (e) Matsumura, M.; Muranaka, A.; Kurihara, R.; Kanai, M.; Yoshida, K.; Kakusawa, N.; Hashizume, D.; Uchiyama, M.; Yasuike, S. General Synthesis, Structure, and Optical Properties of Benzothiophene-Fused Benzoheteroles Containing Group 15 and 16 Elements. Tetrahedron 2016, 72, 8085; (f) Pihera, P.; Palecek, H.; Svoboda, J. Diels-Alder Reactions of [1]Benzothieno[3,2-b]furan. Collect. Czech. Chem. Commun. 1998, 63, 681. DOI: 10.1135/cccc19980681.
  • Iino, H.; Usui, T.; Hanna, J.-I. Liquid Crystals for Organic thin-film transistors. Nat. Commun. 2015, 6, 6828. DOI: 10.1038/ncomms7828.
  • Yang, K.; Pulis, A. P.; Perry, G. J. P.; Procter, D. J. Transition-Metal-Free Synthesis of C3-Arylated Benzofurans from Benzothiophenes and Phenols. Org. Lett. 2018, 20, 7498. DOI: 10.1021/acs.orglett.8b03267.
  • (a) Ortgies, D. H.; Hassanpour, A.; Chen, F.; Woo, S.; Forgione, P. Desulfination as an Emerging Strategy in Palladium‐Catalyzed C–C Coupling Reactions. Eur. J. Org. Chem. 2016, 2016, 408; (b) Markovic, T.; Rocke, B. N.; Blakemore, D. C.; Mascitti, V.; Willis, M. C. Pyridine Sulfinates as General Nucleophilic Coupling Partners in Palladium-Catalyzed Cross-Coupling Reactions with Aryl Halides. Chem. Sci. 2017, 8, 4437. DOI: 10.1039/c7sc00675f.

Reprints and Corporate Permissions

Please note: Selecting permissions does not provide access to the full text of the article, please see our help page How do I view content?

To request a reprint or corporate permissions for this article, please click on the relevant link below:

Academic Permissions

Please note: Selecting permissions does not provide access to the full text of the article, please see our help page How do I view content?

Obtain permissions instantly via Rightslink by clicking on the button below:

If you are unable to obtain permissions via Rightslink, please complete and submit this Permissions form. For more information, please visit our Permissions help page.