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Synlett 2019; 30(10): 1183-1186
DOI: 10.1055/s-0037-1611774
DOI: 10.1055/s-0037-1611774
cluster
Efficient Flow Electrochemical Alkoxylation of Pyrrolidine-1-carbaldehyde
Further Information
Publication History
Received: 31 January 2019
Accepted after revision: 11 February 2019
Publication Date:
26 March 2019 (online)
Published as part of the Cluster Electrochemical Synthesis and Catalysis
Abstract
We report on the optimization of the alkoxylation of pyrrolidine-1-carbaldehyde by using a new electrochemical microreactor. Precise control of the reaction conditions permits the synthesis of either mono- or dialkoxylated reaction products in high yields.
Key words
C–H activation - electrochemistry - flow chemistry - heterocycles - alkoxylation - pyrrolidinecarbaldehydeSupporting Information
- Supporting information for this article is available online at https://doi.org/10.1055/s-0037-1611774.
- Supporting Information
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References and Notes
- 1a Little RD, Moeller KD. Chem. Rev. 2018; 118: 4483
- 1b Francke R, Schille B, Roemelt M. Chem. Rev. 2018; 118: 4631
- 1c Yoshida JI, Shimizu A, Hayashi R. Chem. Rev. 2018; 118: 4702
- 1d Moeller KD. Chem. Rev. 2018; 118: 4817
- 1e Nutting JE, Rafiee M, Stahl SS. Chem. Rev. 2018; 118: 4834
- 2a Frontana-Uribe BA, Little RD, Ibanez JG, Palma A, Vasquez-Medrano R. Green Chem. 2010; 12: 2099
- 2b Organic Electrochemistry, 5th ed. . Hammerich O, Speiser B. CRC Press; Boca Raton: 2015
- 2c Horn EJ, Rosen BR, Baran PS. ACS Cent. Sci. 2016; 2: 302
- 3a Yoshida J. Electrochem. Soc. Interface 2009; (Summer) 40
- 3b Folgueiras-Amador AA, Wirth T. J. Flow Chem. 2017; 7: 94
- 3c Atobe M, Tateno H, Matsumura Y. Chem. Rev. 2018; 118: 4541
- 3d Pletcher D, Green RA, Brown RC. D. Chem. Rev. 2018; 118: 4573
- 3e Folgueiras-Amador AA, Wirth T. In Flow Chemistry in Organic Synthesis . Jamison TF, Koch G. Thieme; Stuttgart: 2018. Chap. 5, 147
- 4 Yoo SJ, Li L.-J, Zeng C.-C, Little RD. Angew. Chem. Int. Ed. 2015; 54: 3744
- 5a Horii D, Atobe M, Fuchigami T, Marken F. Electrochem. Commun. 2005; 7: 35
- 5b Horcajada R, Okajima M, Suga S, Yoshida J.-i. Chem. Commun. 2005; 1303
- 5c He P, Watts P, Marken F, Haswell SJ. Angew. Chem. Int. Ed. 2006; 45: 4146
- 5d Kuleshova J, Hill-Cousins JT, Birkin PR, Brown RC. D, Pletcher D, Underwood TJ. Electrochim. Acta 2011; 56: 4322
- 5e Attour A, Dirrenberger P, Rode S, Ziogas A, Matlosz M, Lapicque F. Chem. Eng. Sci. 2011; 66: 480
- 5f Kashiwagi T, Elsler B, Waldvogel SR, Fuchigami T, Atobe M. J. Electrochem. Soc. 2013; 160: G3058
- 6a Watts K, Gattrell W, Wirth T. Beilstein J. Org. Chem. 2011; 7: 1108
- 6b Arai K, Watts K, Wirth T. ChemistryOpen 2014; 3: 23
- 6c Arai K, Wirth T. Org. Process Res. Dev. 2014; 18: 1377
- 6d Folgueiras-Amador AA, Philipps K, Guilbaud S, Poelakker J, Wirth T. Angew. Chem. Int. Ed. 2017; 56: 15446
- 6e Folgueiras-Amador AA, Qian X.-Y, Xu H.-C, Wirth T. Chem. Eur. J. 2018; 24: 487
- 6f Gao W.-C, Xiong Z.-Y, Pirhaghani S, Wirth T. Synthesis 2019; 51: 276
- 6g Islam M, Kariuki BM, Shafiq Z, Wirth T, Ahmed N. Eur. J. Org. Chem. 2019; 1371
- 7 For details of the Ion electrochemical reactor, see: https://www.vapourtec.com/products/flow-reactors/ion-electrochemical-reactor-features/ (accessed Mar 15, 2019).
- 8a Kuleshova J, Hill-Cousins JT, Birkin PR, Brown RC. D, Pletcher D, Underwood TJ. Electrochim. Acta 2012; 69: 197
- 8b Green RA, Brown RC. D, Pletcher D, Harji B. Org. Process Res. Dev. 2015; 19: 1424
- 8c Green RA, Brown RC. D, Pletcher D, Harji B. Electrochem. Commun. 2016; 73: 63
- 8d Folgueiras-Amador AA, Jolley KE, Birkin PR, Brown RC. D, Pletcher D, Pickering S, Sharabi M, de Frutos O, Mateos C, Rincón JA. Electrochem. Commun. 2019; 100: 6
- 9 18% Cr, 8% Ni.
- 10 Amemiya F, Kashiwagi T, Fuchigami T, Atobe M. Chem. Lett. 2011; 40: 606
- 11 Cedheim L, Eberson L, Helgee B, Nyberg K, Servin R, Sternerup H. Acta Chem. Scand., Ser. B 1975; 29: 617
- 12 Chapman MR, Shafi YM, Kapur N, Nguyen BN, Willans CE. Chem. Commun. 2015; 51: 1282
- 13a Liebner R, Schmid P, Adelwöhrer C, Rosenau T. Tetrahedron 2007; 63: 11817
- 13b Stewart WE, Siddall TH. Chem. Rev. 1970; 70: 517
- 14 Mitzlaff M, Warning K, Jensen H. Liebigs Ann. Chem. 1978; 1713
- 15 2-Methoxypyrrolidine-1-carbaldehyde (2); Typical ProcedureA 0.1 M solution of aldehyde 1 in MeOH (60 mL) containing Et4NBF4 (0.05 M) was sonicated to ensure complete dissolution of the reactant, then pumped through one microreactor at 0.5 mL/min by using a syringe pump or the Vapourtec E series, while a constant current of 640 mA was applied. The first 5 mL were discarded, and the remaining reaction mixture was collected for 110 min (55 mL). MeOH was removed under reduced pressure, and the crude product was washed with H2O (50 mL), to remove the supporting electrolyte, then extracted with CH2Cl2 (3 × 30 mL). The organic layers were combined, dried (MgSO4), filtered, evaporated, and dried under high vacuum. The residue was purified by chromatography [silica gel, hexane–EtOAc (1:1)] to give a colorless oil; yield: 629 mg (89%). The NMR spectra showed the presence of a ~5:1 mixture of rotamers.1H NMR (400 MHz, CDCl3): δ (major) = 8.40 (s, 1 H), 4.92 (d, J = 4.8 Hz, 1 H), 3.58−3.40 (m, 2 H), 3.26 (s, 3 H), 2.13−1.79 (m, 4 H); δ (minor) = 8.29 (s, 1 H), 5.37 (d, J = 4.8 Hz, 1 H), 3.58−3.40 (m, 2 H), 3.38 (s, 3 H), 2.13−1.79 (m, 4 H). 13C NMR (101 MHz, CDCl3): δ (major) = 161.4, 89.7, 54.4, 42.7, 31.8, 21.4; δ (minor) = 162.6, 85.5, 56.6, 45.2, 31.9, 22.1.