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Mini-Reviews in Organic Chemistry

Author(s): Humaira Y. Gondal*, Muhammad Nisar, Zain M. Cheema, Kiran Iqbal, Akhtar Munir, Sadia Zaidi and Ahmed Abbas Khan

DOI: 10.2174/1570193X20666230124102142

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Synthesis and Applications of N-Alkoxymethylated Azaheterocycles

Page: [370 - 404] Pages: 35

  • * (Excluding Mailing and Handling)

Abstract

Alkoxmethyl heterocycles play a significant role as bioactive compounds in pharmaceutical and bifunctional ligands in synthetic organic chemistry. N-Alkoxmethylation can lead toward multipurpose mixed acetals, natural product precursors, and task-specific functionalized ionic liquids. This report provides a comprehensive account of the synthesis and perspectives applications of alkoxymethyl azaheterocycles. The first part gives a detailed account of the different synthetic strategies employed to access N-alkoxy methyl heterocyclic compounds. The second part deals with their applications, owing to the unique reactivity of the alkoxymethyl group and the nature of heterocycle. Besides diverse biological and synthetic applications, alkoxymethyl benzotriazoles also provide substantial scope as a versatile anion stabilizer that can lead to diverse oxygen functionalities.

Graphical Abstract

[1]
Joule, J.A.; Mills, K. Heterocyclic Chemistry at a Glance; John Wiley & Sons: Hoboken, 2012.
[http://dx.doi.org/10.1002/9781118380208]
[2]
Marcantoni, E.; Petrini, M. Recent developments in the stereoselective synthesis of nitrogen-containing heterocycles using n -acylimines as reactive substrates. Adv. Synth. Catal., 2016, 358(23), 3657-3682.
[http://dx.doi.org/10.1002/adsc.201600644]
[3]
Busto, E.; Gotor-Fernández, V.; Gotor, V. Hydrolases in the stereoselective synthesis of N-heterocyclic amines and amino acid derivatives. Chem. Rev., 2011, 111(7), 3998-4035.
[http://dx.doi.org/10.1021/cr100287w] [PMID: 21526748]
[4]
Hameed, A.; Javed, S.; Noreen, R.; Huma, T.; Iqbal, S.; Umbreen, H.; Gulzar, T.; Farooq, T. Facile and green synthesis of saturated cyclic amines. Molecules, 2017, 22(10), 1691.
[http://dx.doi.org/10.3390/molecules22101691] [PMID: 29023406]
[5]
Gaba, M.; Mohan, C. Development of drugs based on imidazole and benzimidazole bioactive heterocycles: Recent advances and future directions. Med. Chem. Res., 2016, 25(2), 173-210.
[http://dx.doi.org/10.1007/s00044-015-1495-5]
[6]
Talukdar, R. Indian society of gastroenterology. Indian J. Gastroenterol., 2015, 34(S1), 1-104.
[http://dx.doi.org/10.1007/s12664-015-0600-5]
[7]
Li, M.; Luo, B.; Liu, Q.; Hu, Y.; Ganesan, A.; Huang, P.; Wen, S. Synthesis of N-acyl-N,O-acetals mediated by titanium ethoxide. Org. Lett., 2014, 16(1), 10-13.
[http://dx.doi.org/10.1021/ol4031155] [PMID: 24308842]
[8]
Hu, B.; Li, J.; Cao, W.; Lin, Q.; Yang, J.; Lin, L.; Liu, X.; Feng, X. Asymmetric synthesis of fused bicyclic N,O - and O,O -acetals via cascade reaction by gold(i)/N,N ′-dioxide-nickel(ii) bimetallic relay catalysis. Adv. Synth. Catal., 2018, 360(15), 2831-2835.
[http://dx.doi.org/10.1002/adsc.201800576]
[9]
Vida, J.A.; Samour, C.M.; Reinhard, J.F. Anticonvulsants. 1. alkoxymethyl derivatives of barbiturates and diphenylhydantoin. J. Med. Chem., 1971, 14(3), 187-189.
[http://dx.doi.org/10.1021/jm00285a002] [PMID: 5552206]
[10]
Vida, J.A.; Wilber, W.R.; Reinhard, J.F. Anticonvulsants. 2. acyloxymethyl and halomethyl derivatives of barbituric acid and diphenylhydantoin. J. Med. Chem., 1971, 14(3), 187-189.
[http://dx.doi.org/10.1021/jm00285a002] [PMID: 5552206]
[11]
Vida, J.A.; Hooker, M.L.; Reinhard, J.F. Anticonvulsants. 3. phenobarbital and mephobarbital derivatives. J. Med. Chem., 1973, 16(6), 602-605.
[http://dx.doi.org/10.1021/jm00264a005] [PMID: 4714988]
[12]
Vida, J.A.; O’Dea, M.H.; Samour, C.M.; Reinhard, J.F. Anticonvulsants. 5. derivatives of 5-ethyl-5-phenylhydantoin and 5,5-diphenylhydantoin. J. Med. Chem., 1975, 18(4), 383-385.
[http://dx.doi.org/10.1021/jm00238a012] [PMID: 1121005]
[13]
Koshchienko, Y.V.; Simonov, A.M.; Vashchenko, T.N.; Suvorova, G.M.; Makarov, V.A. Synthesis and antibacterial activity] of 3-alkoxymethyl-2-amino-1-methylbenzimidazolium chlorides. Pharm. Chem. J., 1977, 11(4), 452-454.
[http://dx.doi.org/10.1007/BF01156476]
[14]
Kishimoto, T.; Matsuo, M.; Ueda, I. Neurotropic and psychotropic agents. VI. 1-Alkoxymethyl-1,3-dihydro-2H-1,4-benzodiazepin-2-ones. Chem. Pharm. Bull., 1982, 30(4), 1477-1480.
[http://dx.doi.org/10.1248/cpb.30.1477] [PMID: 7201889]
[15]
Katritzky, A.R.; Rachwal, S.; Caster, K.C.; Mahni, F.; Law, K.W.; Rubio, O. The chemistry of N-substituted benzotriazoles. Part 1.1-(Chloromethyl)benzotriazole. J. Chem. Soc., Perkin Trans. 1, 1987, 781-789.
[http://dx.doi.org/10.1039/p19870000781]
[16]
Katritzky, A.R.; Rachwal, S.; Rachwal, B. Reactions of 1-(.alpha.-alkoxyalkyl)- and 1-(.alpha.-(aryloxy)alkyl)benzotriazoles with the Grignard reagents. A new and versatile method for the preparation of ethers. J. Org. Chem., 1989, 54(26), 6022-6029.
[http://dx.doi.org/10.1021/jo00287a011]
[17]
Weglewski, J.; Pernak, J.; Krysinski, J. Synthesis and bactericidal properties of pyridinium chlorides with alkylthiomethyl and alkoxymethyl hydrophobic groups. J. Pharm. Sci., 1991, 80(1), 91-95.
[http://dx.doi.org/10.1002/jps.2600800122] [PMID: 2013858]
[18]
Katritzky, A.R.; Rachwal, S.; Rachwal, B.; Steel, P.J. Additions of 1-(.alpha.-alkoxybenzyl)benzotriazoles to enol ethers. new routes to 1,3-diethers. J. Org. Chem., 1992, 57(18), 4925-4931.
[http://dx.doi.org/10.1021/jo00044a030]
[19]
Kameswaran, V.; Barton, J.M. U.S. Patent No. 5, 1992.
[20]
Singh, M.; Bathini, Y.; Lown, J. Site selective alkoxymethylation of imidazo [4, 5-b] pyridines: Structural analysis by high field NMR methods. Heterocycles, 1993, 36, 971-985.
[http://dx.doi.org/10.3987/COM-92-6224]
[21]
Juliusz, P.; Lucyna, M. 1-Alkoxymethyl-and 1-alkylthiomethyl-4-dimethylaminopyridinium chlorides. Heterocycles, 1994, 37(1), 311-321.
[http://dx.doi.org/10.3987/COM-93-S5]
[22]
Hachiam, A.F.H.; Plenkiewicz, J.L. Ortho-hydroxybenzylation and alkoxymethylation of 5-phenyltetrazole. Synth. Commun., 1994, 24(5), 665-670.
[http://dx.doi.org/10.1080/00397919408012643]
[23]
Katritzky, A.R.; Lan, X.; Fan, W.Q. Benzotriazole as a synthetic auxiliary: Benzotriazolylalkylations and benzotriazole-mediated heteroalkylation. Synthesis, 1994, 1994(5), 445-456.
[http://dx.doi.org/10.1055/s-1994-25496]
[24]
Katritzky, A.R.; Lang, H.; Wang, Z.; Zhang, Z.; Song, H. Benzotriazole-mediated conversions of aromatic and heteroaromatic aldehydes to functionalized ketones. J. Org. Chem., 1995, 60(23), 7619-7624.
[http://dx.doi.org/10.1021/jo00128a039]
[25]
Pernak, J.; Michalak, L.; Krysinski, J.; Kuncewicz, Z. Synthesis and antibiotic activity of 1-cycloalkoxymethyl-4-dimethylaminopyridinium and 1-[(1-alkoxy)ethyl]-4-dimethylaminopyridinium chlorides. Arch. Pharm., 1995, 328(6), 531-533.
[http://dx.doi.org/10.1002/ardp.19953280611] [PMID: 7677568]
[26]
Katritzky, A.R.; Feng, D.; Lang, H. Benzotriazole- and 1,2,4-triazole-stabilized allylic anions: Applications in syntheses of functionalized α, β-unsaturated ketones, γ-lactones, γ-lactams, and β-substituted esters. J. Org. Chem., 1997, 62(3), 706-714.
[http://dx.doi.org/10.1021/jo961396t] [PMID: 11671468]
[27]
Pernak, J.; Czepukowicz, A. Poźniak, R. New ionic liquids and their antielectrostatic properties. Ind. Eng. Chem. Res., 2001, 40(11), 2379-2383.
[http://dx.doi.org/10.1021/ie000689g]
[28]
Pernak, J. Rogoża, J.; Mirska, I. Synthesis and antimicrobial activities of new pyridinium and benzimidazolium chlorides. Eur. J. Med. Chem., 2001, 36(4), 313-320.
[http://dx.doi.org/10.1016/S0223-5234(01)01226-0] [PMID: 11461756]
[29]
Pernak, J.; Branicka, M. The properties of 1-alkoxymethyl-3-hydroxypyridinium and 1-alkoxymethyl-3-dimethylaminopyridinium chlorides. J. Surfactants Deterg., 2003, 6(2), 119-123.
[http://dx.doi.org/10.1007/s11743-003-0254-5]
[30]
Pernak, J.; Feder-Kubis, J. Chiral pyridinium-based ionic liquids containing the (1R,2S,5R)-(−)-menthyl group. Tetrahedron Asymmetry, 2006, 17(11), 1728-1737.
[http://dx.doi.org/10.1016/j.tetasy.2006.06.014]
[31]
Pernak, J.; Kalewska, J. Ksycińska, H.; Cybulski, J. Synthesis and anti-microbial activities of some pyridinium salts with alkoxymethyl hydrophobic group. Eur. J. Med. Chem., 2001, 36(11-12), 899-907.
[http://dx.doi.org/10.1016/S0223-5234(01)01280-6] [PMID: 11755232]
[32]
Pernak, J.; Sobaszkiewicz, K.; Foksowicz-Flaczyk, J. Ionic liquids with symmetrical dialkoxymethyl-substituted imidazolium cations. Chemistry, 2004, 10(14), 3479-3485.
[http://dx.doi.org/10.1002/chem.200400075] [PMID: 15252794]
[33]
Szmigielski, R.; Danikiewicz, W. N-alkoxymethylation of secondary amides, sulfonamides and phosphamides using dialkoxymethanes in the presence of lewis acids. Synlett, 2003, 2003, 0372-0376.
[http://dx.doi.org/10.1055/s-2003-37116]
[34]
Bharate, S.B.; Thompson, C.M. Antimicrobial, antimalarial, and antileishmanial activities of mono- and bis-quaternary pyridinium compounds. Chem. Biol. Drug Des., 2010, 76(6), 546-551.
[http://dx.doi.org/10.1111/j.1747-0285.2010.01035.x] [PMID: 21040494]
[35]
Sakai, N.; Asano, J.; Shimano, Y.; Konakahara, T. Hf(OTf)4-doped me 3 sicl-catalyzed aminomethylation of arenes with N,O-acetals: Facile approach to non-natural aromatic amino acid precursors. Synlett, 2007, 2007(17), 2675-2678.
[http://dx.doi.org/10.1055/s-2007-991060]
[36]
Kadutskii, A.P.; Kozlov, N.G. Synthesis of spirocyclic benzo[f]quinoline derivatives by cascade heterocyclization of dimedone, 2-naphthylamine, and formaldehyde. Russ. J. Org. Chem., 2006, 42(6), 855-859.
[http://dx.doi.org/10.1134/S1070428006060078]
[37]
Fei, Z.; Ang, W.H.; Zhao, D.; Scopelliti, R.; Zvereva, E.E.; Katsyuba, S.A.; Dyson, P.J. Revisiting ether-derivatized imidazolium-based ionic liquids. J. Phys. Chem. B, 2007, 111(34), 10095-10108.
[http://dx.doi.org/10.1021/jp073419l] [PMID: 17676796]
[38]
Stasiewicz, M.; Fojutowski, A.; Kropacz, A.; Pernak, J. 1-alkoxymethyl-x-dimethylaminopyridinium-base ionic liquids in wood preservation. Hozforschung, 2008, 62(3), 309-317.
[http://dx.doi.org/10.1515/HF.2008.028]
[39]
Feder-Kubis, J.; Kubicki, M.; Pernak, J. 3-Alkoxymethyl-1-(1R,2S,5R)-(−)-menthoxymethylimidazolium salts-based chiral ionic liquids. Tetrahedron Asymmetry, 2010, 21(21-22), 2709-2718.
[http://dx.doi.org/10.1016/j.tetasy.2010.10.029]
[40]
Pan, S.; Liu, J.; Li, H.; Wang, Z.; Guo, X.; Li, Z. Iron-catalyzed N-alkylation of azoles via oxidation of C-H bond adjacent to an oxygen atom. Org. Lett., 2010, 12(9), 1932-1935.
[http://dx.doi.org/10.1021/ol100670m] [PMID: 20377238]
[41]
Quan, Z.J.; Ren, R.G.; Jia, X.D.; Da, Y.X.; Zhang, Z.; Wang, X.C. N-Alkoxymethylation of heterocyclic compounds with diethyl phosphite via cleavage of P–O bond. Tetrahedron, 2011, 67(13), 2462-2467.
[http://dx.doi.org/10.1016/j.tet.2011.01.061]
[42]
Minamitsuji, Y.; Kawaguchi, A.; Kubo, O.; Ueyama, Y.; Maegawa, T.; Fujioka, H. A mild and versatile method for the synthesis of alkyl ethers from methoxymethyl ethers and application to the preparation of sterically crowded ethers. Adv. Synth. Catal., 2012, 354(10), 1861-1866.
[http://dx.doi.org/10.1002/adsc.201200290]
[43]
Tang, S.; Baker, G.A.; Zhao, H. Ether- and alcohol-functionalized task-specific ionic liquids: attractive properties and applications. Chem. Soc. Rev., 2012, 41(10), 4030-4066.
[http://dx.doi.org/10.1039/c2cs15362a] [PMID: 22456483]
[44]
Feder-Kubis, J.; Szefczyk, B.; Kubicki, M. Symmetrical imidazolium chloride based on (-)-menthol: Synthesis, characterization, and theoretical model of the reaction. J. Org. Chem., 2015, 80(1), 237-246.
[http://dx.doi.org/10.1021/jo502317m] [PMID: 25437429]
[45]
Aruri, H.; Singh, U.; Sharma, S.; Gudup, S.; Bhogal, M.; Kumar, S.; Singh, D.; Gupta, V.K.; Kant, R.; Vishwakarma, R.A.; Singh, P.P. Cross-dehydrogenative coupling of azoles with α-C(sp3)-H of ethers and thioethers under metal-free conditions: Functionalization of H-N azoles via C-H activation. J. Org. Chem., 2015, 80(3), 1929-1936.
[http://dx.doi.org/10.1021/jo502477r] [PMID: 25588073]
[46]
Feder-Kubis, J.; Flieger, J.; Tatarczak-Michalewska, M.; Płazińska, A.; Madejska, A.; Swatko-Ossor, M. Renewable sources from plants as the starting material for designing new terpene chiral ionic liquids used for the chromatographic separation of acidic enantiomers. RSC Advances, 2017, 7(51), 32344-32356.
[http://dx.doi.org/10.1039/C7RA03310A]
[47]
Gulçin, İ.; Abbasova, M.; Taslimi, P.; Huyut, Z.; Safarova, L.; Sujayev, A.; Farzaliyev, V.; Beydemir, Ş.; Alwasel, S.H.; Supuran, C.T. Synthesis and biological evaluation of aminomethyl and alkoxymethyl derivatives as carbonic anhydrase, acetylcholinesterase and butyrylcholinesterase inhibitors. J. Enzyme Inhib. Med. Chem., 2017, 32(1), 1174-1182.
[http://dx.doi.org/10.1080/14756366.2017.1368019] [PMID: 28891347]
[48]
Ivanova, А.Е.; Shchegol´kov, E.V.; Burgart, Y.V.; Saloutin, V.I. Hydroxy- and alkoxymethylation of polyfluoroalkyl pyrazoles. Russ. Chem. Bull., 2018, 67(3), 521-524.
[http://dx.doi.org/10.1007/s11172-018-2104-9]
[49]
Mumtaz, S.; Cano, I.; Mumtaz, N.; Abbas, A.; Dupont, J.; Gondal, H.Y. Supramolecular interaction of non-racemic benzimidazolium based ion pairs with chiral substrates. Phys. Chem. Chem. Phys., 2018, 20(32), 20821-20826.
[http://dx.doi.org/10.1039/C8CP03881C] [PMID: 30059112]
[50]
Wu, X.; Qiao, K.; Qin, H.; Zhang, D.; Gao, D.; Yang, Z.; Fang, Z.; Guo, K. Silver(I)-mediated oxidative C(sp3)–H amination of ethers with azole derivatives under mild conditions. Org. Chem. Front., 2019, 6(15), 2672-2677.
[http://dx.doi.org/10.1039/C9QO00644C]
[51]
He, J.; Yu, Y.; Guo, P.; Liu, X.; Zhu, B.; Cao, H. Palladium‐catalyzed c‐n bond formation: A straightforward alkoxymethylation process for the synthesis of the C1 and C3‐dialkoxy indoles. ChemistrySelect, 2020, 5(48), 15148-15152.
[http://dx.doi.org/10.1002/slct.202004226]
[52]
Gondal, H.Y.; Mumtaz, S.; Abbaskhan, A.; Mumtaz, N.; Cano, I. New alkoxymethyl-functionalized pyridinium-based chiral ionic liquids: Synthesis, characterization and properties. Chem. Pap., 2020, 74(9), 2951-2963.
[http://dx.doi.org/10.1007/s11696-020-01135-z]
[53]
Samanta, S.; Mahato, S.; Chatterjee, R.; Santra, S.; Zyryanov, G.V.; Majee, A. Nano indium oxide-catalyzed domino reaction for the synthesis of N-alkoxylated benzimidazoles. Tetrahedron Lett., 2020, 61(32), 152177.
[http://dx.doi.org/10.1016/j.tetlet.2020.152177]
[54]
Borys, A.M.; Gil-Negrete, J.M.; Hevia, E. Atom-efficient transition-metal-free arylation of N, O -acetals using diarylzinc reagents through Zn/Zn cooperativity. Chem. Commun., 2021, 57(71), 8905-8908.
[http://dx.doi.org/10.1039/D1CC04137A] [PMID: 34486629]
[55]
Gondal, H.Y.; Nisar, M.; Cheema, Z.M.; Abbasskhan, A. Lewis acid-catalyzed synthesis of alkoxymethylhalides for multipurpose mixed acetals; scope and limitations. Lett. Org. Chem., 2022, 19(9), 750-756.
[http://dx.doi.org/10.2174/1570178619666220112105145]
[56]
Sundberg, R.J.; Russell, H.F. Syntheses with N-protected 2-lithioindoles. J. Org. Chem., 1973, 38(19), 3324-3330.
[http://dx.doi.org/10.1021/jo00959a018]
[57]
Medvedeva, M.M.; Pozharskii, A.F. Imidazole derivatives that contain potentially labile groupings attached to the N atom. 7. Synthesis of 1-substituted 2-aminobenzimidazoles by ammonolysis of 1-R-3-methoxybenzimidazolium salts. Chem. Heterocycl. Compd., 1982, 18(8), 830-832.
[http://dx.doi.org/10.1007/BF00506589]
[58]
Katritzky, A.R.; Rachwal, S.; Hitchings, G.J. Benzotriazole: A novel synthetic auxiliary. Tetrahedron, 1991, 47(16-17), 2683-2732.
[http://dx.doi.org/10.1016/S0040-4020(01)87080-0]
[59]
Katritzky, A.R.; Rachwal, S.; Rachwal, B. Addition of benzotriazole to vinyl ethers. Chemistry of the adducts. J. Chem. Soc., Perkin Trans. 1, 1990, (6), 1717-1725.
[http://dx.doi.org/10.1039/p19900001717]
[60]
Katritzky, A.R.; Bayyuk, S.I.; Rachwal, S. An efficient synthesis of ketone enol ethers mediated by N-(1-alkoxyalkyl) benzotriazoles. Synthesis, 1991, 1991(4), 279-283.
[http://dx.doi.org/10.1055/s-1991-26446]
[61]
Katritzky, A.R.; Long, Q.H.; Lue, P.; Jozwiak, A. Benzotriazole-assisted synthesis of enamines. Tetrahedron, 1990, 46(24), 8153-8160.
[http://dx.doi.org/10.1016/S0040-4020(01)81471-X]
[62]
Katritzky, A.R.; Zhao, X.; Shcherbakova, I.V. A novel synthetic approach to ethers. J. Chem. Soc., Perkin Trans. 1, 1991, (12), 3295-3299.
[http://dx.doi.org/10.1039/p19910003295]
[63]
Katritzky, A.R.; Yang, Z.; Cundy, D.J. (Benzotriazol-1-yl)methoxymethyl Anion: A novel methylal anion equivalent. Synth. Commun., 1993, 23(21), 3061-3071.
[http://dx.doi.org/10.1080/00397919308011150]
[64]
Katritzky, A.R.; Zhang, G.; Jiang, J. Novel Routes to Enol Ethers, Unsymmetrical Ketones. alpha.-Bromoalkyl Ketones, 1,4-Diketones, 2-Ethoxy-2-cyclopentenones, and. alpha.-. Keto Enamines. J. Org. Chem., 1995, 60(23), 7605-7611.
[http://dx.doi.org/10.1021/jo00128a037]
[65]
Katritzky, A.R.; Jiang, J. A novel heterocycle-stabilized homoenolate anion and its applications in the syntheses of. beta.-propenoylcarboxylic esters, cyclopropanecarboxylic esters, 1-vinyl-1-ethoxy epoxides, and. gamma.-lactones. J. Org. Chem., 1995, 60(1), 6-7.
[http://dx.doi.org/10.1021/jo00106a003]
[66]
Katritzky, A.R.; Zhang, G.; Jiang, J.; Steel, P.J. A novel o-iminophenyl anion route to heterocycles and ortho-substituted anilines. J. Org. Chem., 1995, 60(23), 7625-7630.
[http://dx.doi.org/10.1021/jo00128a040]
[67]
Katritzky, A.R.; Yang, Z.; Moutou, J.L. Conversion of aldehydes to α-acetoxymethyl ketones: One-carbon homologation with (benzotriazol-1-yl)phenoxymethane. Tetrahedron Lett., 1995, 36(6), 841-844.
[http://dx.doi.org/10.1016/0040-4039(94)02395-R]
[68]
Katritzky, A.R.; Jiang, J. A Novel Heterocycle-Stabilized Allylic Anion Route to Cyclopropanes, 1-Ethoxy-1-vinylethylene Oxides, 1-Hydroxyalkyl 2-Methoxyethyl Ketones, 1-Hydroxyalkyl Vinyl Ketones. beta.-Ethoxy-.beta.-vinylalkyl Alcohols. gamma.-Lactones, and. beta.gamma.-. Unsaturated Carboxylic Acids. J. Org. Chem., 1995, 60(23), 7597-7604.
[http://dx.doi.org/10.1021/jo00128a036]
[69]
Katritzky, A.R.; Xie, L.; Serdyuk, L. Novel and efficient insertions of carbons carrying O-, S-, and n-linked substituents: Synthesis of α-alkoxyalkyl, α-(alkylthio)alkyl, and α-(carbazol-9-yl)alkyl ketones. J. Org. Chem., 1996, 61(21), 7564-7570.
[http://dx.doi.org/10.1021/jo960840p] [PMID: 11667689]
[70]
Katritzky, A.R.; Wang, Z.; Lang, H.; Feng, D. Novel and facile syntheses of alkenyl, alkynyl, and aryl 1, 2-diketones. J. Org. Chem., 1997, 62(12), 4125-4130.
[http://dx.doi.org/10.1021/jo970092j]
[71]
Katritzky, A.R.; Wang, J.; Karodia, N.; Li, J. A novel transformation of esters to alkynes with 1-substituted benzotriazoles. J. Org. Chem., 1997, 62(12), 4142-4147.
[http://dx.doi.org/10.1021/jo962291t]
[72]
Pleynet, D.P.M.; Dutton, J.K.; Peter Johnson, A. A general synthesis of 1-(1-alkenyl)benzotriazoles. Tetrahedron, 1999, 55(40), 11903-11926.
[http://dx.doi.org/10.1016/S0040-4020(99)00690-0]
[73]
Degl’Innocenti, A.; Capperucci, A.; Oniciu, D.C.; Katritzky, A.R. Novel access to thioacylsilanes with benzotriazole-mediated methodology. J. Org. Chem., 2000, 65(26), 9206-9209.
[http://dx.doi.org/10.1021/jo0011585] [PMID: 11149871]
[74]
Hammaecher, C.; Bouillon, J.P.; Portella, C. Towards bis(acylsilanes) and cyclic unsaturated acylsilanes via metathesis: An exploratory study. Tetrahedron, 2009, 65(28), 5527-5534.
[http://dx.doi.org/10.1016/j.tet.2009.02.085]
[75]
Dumas, A.M.; Bode, J.W. Synthesis of acyltrifluoroborates. Org. Lett., 2012, 14(8), 2138-2141.
[http://dx.doi.org/10.1021/ol300668m] [PMID: 22475226]
[76]
Janus, E.; Goc-Maciejewska, I.; Łożyński, M.; Pernak, J. Diels–Alder reaction in protic ionic liquids. Tetrahedron Lett., 2006, 47(24), 4079-4083.
[http://dx.doi.org/10.1016/j.tetlet.2006.03.172]
[77]
Jacquemin, J.; Feder-Kubis, J.; Zorębski, M.; Grzybowska, K.; Chorążewski, M.; Hensel-Bielówka, S.; Zorębski, E.; Paluch, M.; Dzida, M. Structure and thermal properties of salicylate-based-protic ionic liquids as new heat storage media. COSMO-RS structure characterization and modeling of heat capacities. Phys. Chem. Chem. Phys., 2014, 16(8), 3549-3557.
[http://dx.doi.org/10.1039/c3cp54533d] [PMID: 24413748]
[78]
Sakai, N.; Asano, J.; Kawada, Y.; Konakahara, T. Facile Approach to Natural or Non‐Natural Amino Acid Derivatives: Me3SiCl-promoted coupling reactin of organozinc compounds with N,O-acetals. Eur. JOC, 2009, 6, 917-922.
[79]
Sakai, N.; Sato, A.; Konakahara, T. Practical synthesis of natural amino acid derivatives: HF(OTF)4 -catalyzed mannich-type reaction of ketene silyl acetals or enol silyl ethers with N, O -acetals as a glycine cation equivalent. Synlett, 2009, 2009(9), 1449-1452.
[http://dx.doi.org/10.1055/s-0029-1216743]
[80]
Albertshofer, K.; Mani, N.S. Regioselective electrophilic fluorination of rationally designed imidazole derivatives. J. Org. Chem., 2016, 81(3), 1269-1276.
[http://dx.doi.org/10.1021/acs.joc.5b02592] [PMID: 26741948]
[81]
Fujioka, H.; Okitsu, T.; Sawama, Y.; Murata, N.; Li, R.; Kita, Y. Reaction of the acetals with TESOTf-base combination; speculation of the intermediates and efficient mixed acetal formation. J. Am. Chem. Soc., 2006, 128(17), 5930-5938.
[http://dx.doi.org/10.1021/ja060328d] [PMID: 16637661]
[82]
Fujioka, H.; Okitsu, T.; Ohnaka, T.; Li, R.; Kubo, O.; Okamoto, K.; Sawama, Y.; Kita, Y. Organic chemistry using weakly electrophilic salts: Efficient formation of O,O-mixed, O,S- and N,O-acetals. J. Org. Chem., 2007, 72(21), 7898-7902.
[http://dx.doi.org/10.1021/jo071187g] [PMID: 17887700]
[83]
Fujioka, H.; Kita, Y.; Kubo, O.; Senami, K.; Okamoto, K.; Okitsu, T. Organic chemistry using weakly electrophilic salts: The reaction with nitrogen nucleophiles. Heterocycles, 2009, 79(1), 1113-1120.
[http://dx.doi.org/10.3987/COM-08-S(D)69]
[84]
Fujioka, H.; Okitsu, T.; Ohnaka, T.; Sawama, Y.; Kubo, O.; Okamoto, K.; Kita, Y. Reaction of tetrahydropyranyl ethers with triethylsilyl trifluoromethanesulfonate–2,4,6-collidine combination: Speculation on the intermediate, efficient deprotection, and application to efficient ring-closing metathesis as a tether. Adv. Synth. Catal., 2007, 349(4-5), 636-646.
[http://dx.doi.org/10.1002/adsc.200600572]
[85]
Fujioka, H.; Minamitsuji, Y.; Moriya, T.; Okamoto, K.; Kubo, O.; Matsushita, T.; Murai, K. Preparation of THP-ester-derived pyridinium-type salts and their reactions with various nucleophiles. Chem. Asian J., 2012, 7(8), 1925-1933.
[http://dx.doi.org/10.1002/asia.201200234] [PMID: 22639340]
[86]
Fujioka, H.; Okamoto, K.; Minamitsuji, Y.; Ueyama, Y.; Matsumoto, N.; Murai, K. Stereoselective construction of 1β-azide- and 1β-cyano-2-deoxyribose derivatives. Heterocycles, 2015, 90(2), 1142-1157.
[http://dx.doi.org/10.3987/COM-14-S(K)86]
[87]
Fujioka, H.; Matsumoto, N.; Ohta, R.; Yamakawa, M.; Shimizu, N.; Kimura, T.; Murai, K. Organic synthesis based on the beckmann fragmentation: Generation of an electrophilic salt intermediate and successive c–c bond formation using gilman reagents. Tetrahedron Lett., 2015, 56(21), 2656-2658.
[http://dx.doi.org/10.1016/j.tetlet.2015.03.089]
[88]
Kawajiri, T.; Kato, M.; Nakata, H.; Goto, R.; Aibara, S.; Ohta, R.; Fujioka, H.; Sajiki, H.; Sawama, Y. Chemoselective nucleophilic functionalizations of aromatic aldehydes and acetals via pyridinium salt intermediates. J. Org. Chem., 2019, 84(7), 3853-3870.
[http://dx.doi.org/10.1021/acs.joc.8b02965] [PMID: 30747527]