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Synlett 2013; 24(13): 1722-1724
DOI: 10.1055/s-0033-1339313
DOI: 10.1055/s-0033-1339313
letter
Base-Promoted Internal Redox-Cyclisation Reactions
Weitere Informationen
Publikationsverlauf
Received: 24. April 2013
Accepted after revision: 05. Juni 2013
Publikationsdatum:
10. Juli 2013 (online)
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Abstract
A new internal, base-mediated redox-cyclisation reaction has been discovered and developed. In this transformation, the sacrificial reduction of an alkynyl moiety to an alkene allows direct functionalisation of an α-amino C–H bond. This approach allows the preparation of several 1,3-oxazinane derivatives in an atom-efficient manner.
Supporting Information
- for this article is available online at http://www.thieme-connect.com/ejournals/toc/synlett.
- Supporting Information
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References and Notes
- 1a Dyker G. Handbook of C–H Transformations. Applications in Organic Synthesis. Wiley-VCH; Weinheim: 2005
- 1b Labinger JA, Bercaw JE. Nature 2002; 417: 507
- 1c Godula K, Sames D. Science 2006; 312: 67
- 1d Brückl T, Baxter RD, Ishihara Y, Baran PS. Acc. Chem. Res. 2012; 45: 826
- 1e Zhang S.-Y, Zhang F.-M, Tu Y.-Q. Chem. Soc. Rev. 2011; 40: 1937
- 1f Newhouse TP, Baran PS. Angew. Chem. Int. Ed. 2011; 50: 3362
- 2a Pastine SJ, McQuaid KM, Sames D. J. Am. Chem. Soc. 2005; 127: 12180
- 2b Vadola PA, Sames D. J. Am. Chem. Soc. 2009; 131: 16525
- 2c Murarka S, Deb I, Zhang C, Seidel D. J. Am. Chem. Soc. 2009; 131: 13226
- 2d Kang YK, Kim SM, Kim DY. J. Am. Chem. Soc. 2010; 132: 11847
- 2e Mori K, Sueoka S, Akiyama T. J. Am. Chem. Soc. 2011; 133: 2424
- 2f Mori K, Ehara K, Kurihara K, Akiyama T. J. Am. Chem. Soc. 2011; 133: 6166
- 3 Jurberg ID, Peng B, Wöstefeld E, Wasserloos M, Maulide N. Angew. Chem. Int. Ed. 2012; 51: 1950
- 4a Xu M, Miao Z, Bernet B, Vasella A. Helv. Chim. Acta 2005; 88: 2918
- 4b Saha J, Lorenc C, Surana B, Peczuh MW. J. Org. Chem. 2012; 77: 3846
- 5a Bottini AT, Mullikin JA, Morris CJ. J. Org. Chem. 1964; 29: 373
- 5b Phadtare S, Zemlicka J. J. Am. Chem. Soc. 1989; 111: 5925
- 5c Wei L.-L, Hsung RP, Xiong H, Mulder JA, Nkansah NT. Org. Lett. 1999; 1: 2145
- 6 The remainder of the mass balance in these reactions was typically composed of a mixture of oligomeric material, decomposition products and (occasionally) small amounts of cyclisation products isomeric or akin to 5a (Scheme 3).
- 7 No reaction occurred under the optimised conditions; however, when the reaction temperature was raised to 100 °C, the product d-4a was isolated containing 20% deuterium at the indicated position.
- 8 Wei L.-L, Xiong H, Douglas CJ, Hsung RP. Tetrahedron Lett. 1999; 40: 6903
- 9 Typical Procedure; Synthesis of 1,3-Oxazine 4a: To a solution of amino alcohol 3a (62 mg, 0.22 mmol) in THF (5 mL) was added NaH (60% w/w, 1.0 equiv, 8.8 mg, 0.22 mmol) under argon at room temperature and the mixture was stirred at 50 °C overnight. The reaction mixture was then cooled to room temperature, quenched with sat. aq NH4Cl, extracted with EtOAc (3×), dried (Na2SO4), and concentrated under reduced pressure. Purification by column chromatography (pentane–EtOAc, 9:1) afforded the desired product 1,3-oxazinane 4a. 3a-Styryl-2,3,3a,5-tetrahydro-1H-benzo[d]pyrrolo[2,1-b][1,3]oxazine (4a): Yield: 52%. 1H NMR (400 MHz, CDCl3): δ = 7.36–7.33 (m, 2 H), 7.30–7.27 (m, 2 H), 7.23–7.16 (m, 2 H), 6.88 (d, J = 7.2 Hz, 1 H), 6.74 (d, J = 8.1 Hz, 1 H), 6.71–6.67 (m, 1 H), 6.41 (d, J = 15.7 Hz, 1 H), 6.19 (d, J = 15.7 Hz, 1 H), 4.88 (d, J = 14.6 Hz, 1 H), 4.62 (d, J = 14.6 Hz, 1 H), 3.79 (td, J = 8.9, 1.8 Hz, 1 H), 3.36 (ddd, J = 9.8, 8.8, 6.7 Hz, 1 H), 2.25–2.20 (m, 1 H), 2.16–2.09 (m, 1 H), 2.05–1.91 (m, 2 H). 13C NMR (100 MHz, CDCl3): δ = 142.4, 136.1, 133.8, 130.4, 128.5, 127.8, 127.7, 126.8, 124.5, 120.1, 116.7, 113.3, 93.6, 63.5, 50.0, 39.3, 21.3. IR (neat): 3024 (w), 2970 (w), 2841 (w), 1881 (w), 1607 (s), 1497 (s), 1361 (s), 1196 (m), 1029 (m), 973 (m), 747 (s) cm–1. HRMS: m/z calcd for [C19H19NO + H]+: 278.1545; found: 278.1539. Typical Procedure; Synthesis of 1,3-Oxazine 4f: To a solution of amino alcohol 3f (50 mg, 0.15 mmol) in THF (4 mL), NaH (60% w/w, 1.0 equiv, 6.2 mg, 0.15 mmol) was added under argon at room temperature and the mixture was stirred at 50 °C overnight. The reaction mixture was cooled to room temperature, quenched with sat. aq NH4Cl, extracted with EtOAc (3×), dried (Na2SO4), and concentrated under reduced pressure. Purification by column chromatography (pentane–EtOAc, 19:1) afforded the desired 1,3-oxazinane 4f. 3a-[4-(tert-Butyl)styryl]-2,3,3a,5-tetrahydro-1H-benzo[d]pyrrolo[2,1-b][1,3]oxazine (3f): Yield: 38%. 1H NMR (400 MHz, CDCl3): δ = 7.28–7.25 (m, 4 H), 7.12–7.09 (m, 2 H), 6.81–6.77 (m, 1 H), 6.80 (d, J = 7.6 Hz, 1 H), 6.72 (d, J = 8.2 Hz, 1 H), 6.62–6.59 (m, 1 H), 6.31 (d, J = 15.7 Hz, 1 H), 6.08 (d, J = 15.4 Hz, 1 H), 4.80 (d, J = 14.8 Hz, 1 H), 4.54 (d, J = 15.8 Hz, 1 H), 3.71 (td, J = 8.5 Hz, J = 8.4 Hz, 1 H), 3.36 (m, 1 H), 2.16–2.11 (m, 1 H), 2.08–2.02 (m, 1 H), 1.91–1.95 (m,1 H), 1.89–1.82 (m, 1 H), 1.25–1.22 (s, 9 H). 13C NMR (100 MHz, CDCl3): δ = 133.6, 133.1, 129.7, 127.8, 126.8, 125.7, 124.5, 120.3, 116.7, 113.2, 96.6, 93.8, 63.5, 50.3, 39.4, 34.6, 30.9, 21.2. IR (neat): 3024 (w), 2970 (w), 2841 (w), 1830 (w), 1698 (s), 1498 (s), 1362 (s), 1263 (m), 1029 (m), 815 (m), 749 (s) cm–1. HRMS: m/z calcd for [C23H27NO + H]+: 334.2167; found: 334.2165.