Synlett, Table of Contents Synlett 2024; 35(03): 313-318DOI: 10.1055/a-2136-3700 cluster Organic Chemistry Under Visible Light: Photolytic and Photocatalytic Organic Transformations Transition-Metal-Free and Photocatalyst-Free Sulfenylation of Halopyrazolamines under Visible-Light Irradiation via Electron Donor–Acceptor Complexes Markabandhu Shanthi , Karuppaiah Perumal , Soumya Sivalingam , Arulmozhi Puhazhendhi , Pavan Kumar Mandali , Subburethinam Ramesh∗ Recommend Article Abstract Buy Article All articles of this category Abstract A new approach was developed for the thiolation of halogenated pyrazole-5-amines under blue LED irradiation in metal-free conditions. This efficient and practical approach enabled the generation of thiolated pyrazol-5-amine building blocks of medicinal significance. This straightforward technique permits photochemical thiolation by an electron donor–acceptor by two distinct processes; formation of a charge-transfer complex through a halogen bond or π–π interaction based on various halogenated pyrazolamines, depending on the HOMO–LUMO energy gap of the C–X bond. The reaction of halogenated pyrazol-5-amines with thiophenol derivatives proceeded in good to excellent yields. The formation of a π–π complex or halogen bonding between the halopyrazolamine and the thiolate anion was confirmed by UV/visible spectroscopy. Key words Key wordspyrazolamines - EDA - metal-free reaction - photochemical reaction - thiolation Full Text References References and Notes 1a Comprehensive Organic Chemistry: The Synthesis and Reactions of Organic Compounds: Sulphur, Selenium, Silicon, Boron, Organometallic Compounds, Vol. 3. Jones DN. Pergamon; Oxford: 1979 1b Liu L, Stelmach JE, Natarajan SR, Chen M.-H, Singh SB, Schwartz CD, Fitzgerald CE, O’Keefe SJ, Zaller DM, Schmatz DM, Doherty JB. Bioorg. Med. Chem. Lett. 2003; 13: 3979 1c Gangjee A, Zeng Y, Talreja T, McGuire JJ, Kisliuk RL, Queener SF. J. Med. Chem. 2007; 50: 3046 2a Liu G, Huth JR, Olejniczak ET, Mendoza F, Fesik SW, DeVries P, Leitza S, Reilly EB, Okasinski GF, Fesik SW, von Geldern TW. J. Med. Chem. 2001; 44: 1202 2b DeMartino G, Edler MC, La Regina G, Coluccia A, Barbera MC, Barrow D, Nicholson RI, Chiosis G, Brancale A, Hamel E, Artico M, Silvestri R. J. Med. Chem. 2006; 49: 947 2c Beletskaya IP. Ananikov V. P. Chem. Rev. 2011; 111: 1596 2d Scott KA, Njardarson JT. Top. Curr. Chem. 2018; 376: 5 3a Boyd DA. Angew. Chem. Int. Ed. 2016; 55: 15486 3b Rahate AS, Nemade KR, Waghuley SA. Rev. Chem. Eng. 2013; 29: 471 3c Ríos M.-C, Portilla J. Chemistry 2022; 4: 940 3d Afsina CM. A, Aneeja T, Neetha M, Anilkumar G. Curr. Org. Synth. 2021; 18: 197 4 Bekhit AA, Nasralla SN, El-Agroudy EJ, Hamouda N, Abd El-Fattah H, Bekhit SA, Amagase K, Ibrahim TM. Eur. J. Pharm. Sci. 2022; 168: 106080 5 Radulović NS, Nikolić MG, Mladenović MZ, Ranđelovic P, Stojanović NM, Stojanović-Radić Z, Jovanović L. Appl. Organomet. Chem. 2022; 36: e6514 6 Chen Y, Fu X.-D, Mu H.-P, Qin X.-F, Wan R. J. Chem. Res. 2014; 38: 272 7 Naim M, Alam O, Nawaz F, Alam MJ, Alam P. J. Pharm. BioAllied Sci. 2016; 8: 2 8a Mantzanidou M, Pontiki E, Hadjipavlou-Litina D. Molecules 2021; 26: 3439 8b Lyalin BV, Sigacheva VL, Kudinova AS, Neverov SV, Kokorekin AV, Petrosyan AV. Molecules 2021; 26: 4749 8c Kim MM, Ruck RT, Zhao D, Huffman MA. Tetrahedron Lett. 2008; 49: 4026 9a Yan K, Yang D, Sun P, Wei W, Liu Y, Li G, Lu S, Wang H. Tetrahedron Lett. 2015; 56: 4792 9b Dotsey EY, Jung K, Basit A, Wei D, Daglian J, Vacondio F, Armirotti A, Mor M, Piomelli D. Chem. Biol. 2015; 22: 619 10a Saeed A, Channar PA. J. Heterocycl. Chem. 2015; 54: 780 10b Yan K, Yang D, Wei W, Lu S, Li G, Zhao C, Zhang Q, Wang H. Org. Chem. Front. 2016; 3: 66 11a Bhowmik A, Yadav M, Fernandes RA. Org. Biomol. Chem. 2020; 18, 2447 11b Guo Y, Quan Z.-J, Da Y.-Z, Zhang Z, Wang X.-C. RSC Adv. 2015; 5: 45479 12a Hosseinian A, Kheirollahi Nezhad PD, Ahmadi S, Rahmani Z, Monfared A. J. Sulfur Chem. 2018; 40: 88 12b Jia F, He J, Wei Y, Wei Y, Liu Y, Gu Y, Vaccaro L, Liu P. Mol. Catal. 2022; 528: 112485 12c Xu M, Zhang XH, Zhong P. Synth. Commun. 2012; 42: 3472 12d Guo Y, Zhong S, Wei L, Wan J.-P. Beilstein J. Org. Chem. 2017; 13: 2017 13a Sundaravelu N, Sangeetha S, Sekar G. Org. Biomol. Chem. 2021; 19: 1459 13b Mondal S, Khan AT. Synthesis 2022; 54: 4521 13c Xu X.-M, Chen D.-M, Wang Z.-L. Chin. Chem. Lett. 2020; 31: 49 14a Kosugi M, Shimizu T, Migita T. Chem. Lett. 1977; 1423 14b Tanimoto K, Ohkado R, Iida H. J. Org. Chem. 2019; 84: 14980 14c Sun P, Yang D, Wei W, Jiang L, Wang Y, Dai T, Wang H. Org. Chem. Front. 2017; 4: 1367 14d Liu X, Cui H, Yang D, Dai S, Zhang T, Sun J, Wei W. RSC Adv. 2016; 6: 51830 15 Migita T, Shimizu T, Asami Y, Shiobara J, Kato Y, Kosugi M. Bull. Chem. Soc. Jpn. 1980; 53: 1385 16 Duan Z, Ranjit S, Zhang P, Liu X. Chem. Eur. J. 2009; 15: 3666 17 Eichman CC, Stambuli JP. J. Org. Chem. 2009; 74: 4005 18 Jiang Z, She J, Lin X. Adv. Synth. Catal. 2009; 351: 2558 19a Wang S, Wang H, König B. J. Am. Chem. Soc. 2021; 143: 15530 19b Ghosh S, Pyne P, Ghosh A, Choudhury S, Hajra A. Org. Biomol. Chem. 2023; 21: 1591 20a Vara BA, Li X, Berritt S, Walters CR, Petersson EJ, Molander GA. Chem. Sci. 2018; 9: 336 20b Cai S, Xu Y, Chen D, Li L, Chen Q, Huang M, Weng W. Org. Lett. 2016; 18: 2990 20c Srivastava V, Singh PK, Srivastava A, Singh PP. RSC Adv. 2020; 10: 20046 20d Paul S, Das S, Choudhuri T, Sikdar P, Bagdi AK. J. Org. Chem. 2023; 88: 4187 21a Herrera-Luna JC, Pérez-Aguilar MC, Gerken L, García Mancheño O, Jiménez MC, Pérez-Ruiz R. Chem. Eur. J. 2023; 29: e202203353 21b Granados A, Cabrera-Afonso MJ, Escolano M, Badir SO, Molander GA. Chem. Catal. 2022; 2: 898 21c Cai Y.-P, Nie F.-Y, Song Q.-H. J. Org. Chem. 2021; 86: 12419 22 Liu B, Lim C.-H, Miyake GM. J. Am. Chem. Soc. 2017; 139: 13616 23 Li T, Liang K, Tang J, Ding Y, Tong X, Xia C. Chem. Sci. 2021; 12: 15770 24 Jin Y, Yang H, Fu H. Chem. Commun. 2016; 52: 12909 25 Desiraju GR, Ho PS, Kloo L, Legon AC, Marquardt R, Metrangolo P, Politzer P, Resnati G, Rissanen K. Pure Appl. Chem. 2013; 85: 1711 26a Yang D, Yan K, Wei W, Li G, Lu S, Zhao C, Tian L, Wang H. J. Org. Chem. 2015; 80: 11073 26b Feng Y, He J, Wei Y, Xie J, Liu P. Eur. J. Org. Chem. 2022; e202200357 26c Livesley S, Trueman B, Robertson CM, Goundry WR. F, Morris JA, Aïssa C. Org. Lett. 2022; 24: 7015 27a Xu R, Wan J.-P, Mao H, Pan Y. J. Am. Chem. Soc. 2010; 132: 15531 27b Huang W.-K, Chen W.-T, Hsu I.-J, Han C.-C, Shyu S.-G. RSC Adv. 2017; 7: 4912 27c Zhang Q, Hu B, Zhao Y, Zhao S, Wang Y, Zhang B, Yan S, Yu F. Eur. J. Org. Chem. 2020; 1154 28a Yan K, Yang D, Wei W, Lu S, Li G, Zhao C, Zhang Q, Wang H. Org. Chem. Front. 2016; 3: 66 28b Zheng Y, Bian R, Zhang X, Yao R, Qiu L, Bao X, Xu X. Eur. J. Org. Chem. 2016; 3872 29a Yang D, Sun P, Wei W, Meng L, He L, Fang B, Jiang W, Wang H. Org. Chem. Front. 2016; 3: 1457 29b Jana A, Panday AK, Mishra R, Parvin T, Choudhury LH. ChemistrySelect 2017; 2: 9420 30a Babiola Annes S, Saritha R, Chandru K, Mandali PK, Ramesh S. J. Org. Chem. 2021; 86: 16473 30b Saritha R, Babiola Annes S, Perumal K, Shankar B, Ramesh S. J. Org. Chem. 2022; 87: 13856 31 Saritha R, Babiola Annes S, Ramesh S. RSC Adv. 2021; 11: 14079 32 3-Methyl-1-phenyl-4-(phenylsulfanyl)-1H-pyrazol-5-amine (5a); Typical Procedure A mixture of 4-iodopyrazol-5-amine 4a (0.299 g, 1 mmol), PhSH (0.330 g, 3 mmol), and Cs2CO3 (0.977 g, 3 mmol) with DMSO (3 mL) was irradiated with blue LED light (9 W) for 24 h in a closed vessel. When the reaction was complete (TLC), the mixture was extracted with EtOAc and H2O. The combined organic layer was dried (Na2SO4), then purified by column chromatography [silica gel (60–120 mesh), EtOAc–hexane] to give a brown solid; yield: 227 mg (81%); mp 72–74 °C; Rf = 0.35 (20% EtOAc–hexane). 1H NMR (600 MHz, CDCl3): δ = 7.54–7.45 (m, 2 H), 7.35 (tt, J = 6.0, 6.2 Hz, 1 H), 7.26–7.23 (m, 2 H), 7.11 (d, J = 6.0 Hz, 3 H), 4.22 (s, 2 H), 2.24 (s, 3 H). 33 Li T, Liang K, Tang J, Ding Y, Tong X, Xia C. Chem. Sci. 2021; 12: 15655 Supplementary Material Supplementary Material Supporting Information
