Glycosylation by Alkyne Activation of the 2-O-Substituted Propargyl Group in a β-Phenylthioglucoside with a ⁵ S ₁ Conformation

Abstract

Generally, glycosylation reactions activate an anomeric substituent in a glycosyl donor to generate an oxocarbenium ion intermediate. Here we report a novel glycosylation reaction triggered by the activation of a 2-O-substituted propargyl group in a 3,6-O-1,1′-[(ethane-1,2-diyl)bibenzene-2,2′-bis(methylene)]-β-thioglucoside. This reaction proceeds through a cationic Au(I)-mediated intramolecular migration of the anomeric substituent onto the alkyne moiety of the propargyl group, followed by α-attack by the hydroxy group in the glycosyl acceptor on the oxocarbenium ion. The migration of the anomeric group occurs selectively through a 6-exo-dig pathway. The 2-(phenylsulfanyl)prop-2-en-1-yl group produced during the glycosylation is removable under conditions similar to those used for removing an allyl group. This reaction will be developed for further applications in orthogonal oligosaccharide synthesis.

Key words

glycosylation - stereoselectivity - propargyl group - gold catalysis - intramolecular migration

Publication History

Received: 18 January 2021

Accepted after revision: 05 February 2021

Accepted Manuscript online:
05 February 2021

Article published online:
22 February 2021

• References and Notes

• 1 Handbook of Chemical Glycosylation: Advances in Stereoselectivity and Therapeutic Relevance. Demchenko AV. Wiley-VCH; Weinheim: 2008

For selected reviews, see:
• 2a Bauer EB. Org. Biomol. Chem. 2020; 18: 9160
• 2b Panza M, Pistorio SG, Stine KJ, Demchenko AV. Chem. Rev. 2018; 118: 8105
• 2c Nielsen MM, Pedersen CM. Chem. Rev. 2018; 118: 8285
• 2d Das R, Mukhopadhyay B. ChemistryOpen 2016; 5: 401
• 2e Zhu X, Schmidt RR. Angew. Chem. Int. Ed. 2009; 48: 1900

Although a remarkable glycosylation has been recently reported, the reaction pathway is similar to that shown in Scheme [1a]; see:
• 3a Xiao X, Zeng J, Fang J, Sun J, Li T, Song Z, Cai L, Wan Q. J. Am. Chem. Soc. 2020; 142: 5498
• 3b Meng L, Wu P, Fang J, Xiao Y, Xiao X, Tu G, Ma X, Teng S, Zeng J, Wan Q. J. Am. Chem. Soc. 2019; 141: 11775
• 3c Tanaka M, Nakagawa A, Nishi N, Iijima K, Sawa R, Takahashi D, Toshima K. J. Am. Chem. Soc. 2018; 140: 3644
• 3d Walk JT, Buchan ZA, Montgomery J. Chem. Sci. 2015; 6: 3448
• 4 Xia M.-j, Yao W, Meng X.-b, Lou Q.-h, Li Z.-j. Tetrahedron Lett. 2017; 58: 2389
• 5 Ikuta D, Hirata Y, Wakamori S, Shimada H, Tomabechi Y, Kawasaki Y, Ikeuchi K, Hagimori T, Matsumoto S, Yamada H. Science 2019; 364: 674
• 6 Motoyama A, Arai T, Ikeuchi K, Aki K, Wakamori S, Yamada H. Synthesis 2018; 50: 282
• 7a Hu Z, Tang Y, Yu B. J. Am. Chem. Soc. 2019; 141: 4806
• 7b Chen X, Shen D, Wang Q, Yang Y, Yu B. Chem. Commun. 2015; 51: 13957
• 7c Yu J, Sun J, Niu Y, Li R, Liao J, Zhang F, Yu B. Chem. Sci. 2013; 4: 3899
• 7d Yang F, Wang Q, Yu B. Tetrahedron Lett. 2012; 53: 5231
• 7e Li Y, Yang X, Liu Y, Zhu C, Yang Y, Yu B. Chem. Eur. J. 2010; 16: 1871
• 7f Li Y, Yang Y, Yu B. Tetrahedron Lett. 2008; 49: 3604

For a review, see:
• 7g Yu B. Acc. Chem. Res. 2018; 51: 507

Recently, a similar glycosylation reaction to that reported by Yu has also been reported, see:
• 8a Shaw M, Thakur R, Kumar A. J. Org. Chem. 2019; 84: 589
• 8b Li X, Li C, Liu R, Wang J, Wang Z, Chen Y, Yang Y. Org. Lett. 2019; 21: 9693
• 8c Mishra B, Neralkar M, Hotha S. Angew. Chem. Int. Ed. 2016; 55: 7786
• 9 A gold(III)-mediated glycosylation through activation of the anomeric propargyl group has been reported, see: Hotha S, Kashyap S. J. Am. Chem. Soc. 2006; 128: 9620
• 10 Codée JD. C, Litjens RE. J. N, van den Bos LJ, Overkleeft HS, van der Marel GA. Chem. Soc. Rev. 2005; 34: 769
• 11a Thummala Y, Raju CE, Purnachandar D, Sreenivasulu G, Doddi VR, Karunakar GV. Eur. J. Org. Chem. 2020; 3560
• 11b Kong X.-F, Zhan F, He G.-X, Pan C.-X, Gu C.-X, Lu K, Mo D.-L, Su G.-F. J. Org. Chem. 2018; 83: 2006
• 11c Naoe S, Saito T, Uchiyama M, Oishi S, Fujii N, Ohno H. Org. Lett. 2015; 17: 1774
• 11d Shibata T, Baba T, Takano H, Kanyiva KS. Adv. Synth. Catal. 2017; 359: 1849
• 11e Nandakumar A, Kiruthika SE, Naveen K, Perumal PT. Org. Biomol. Chem. 2014; 12: 876
• 12 Dong X, Chen L, Zheng Z, Ma X, Luo Z, Zhang L. Chem. Commun. 2018; 54: 8626
• 13 In this investigation, β-19 was detected. See the Supporting Information (SI-5) for details.
• 14 Glycoside 19; Typical Procedure (4-F₃CC₆H₄)₃PAuNTf₂ (20 mM) in CH₂Cl₂ (200 μL, 4.0 μmol) was added to a stirred mixture of 13 (20.0 mg, 33.0 μmol), cyclohexylmethanol (5.9 mg, 51 μmol), and activated MS 4 Å (99 mg) in CH₂Cl₂ (1.3 mL) at 0 °C, and the mixture was stirred for 24 h at 0 °C. Sat. aq NaHCO₃ and Et₂O were added, and the mixture was filtered through a cotton–Celite pad to remove the MS. The aqueous filtrate was extracted with Et₂O, and the combined organic layer was washed successively with H₂O and brine. The combined organic layer was dried (Na₂SO₄), filtered, and concentrated, and the residue was purified by column chromatography [silica gel, hexane–EtOAc (15:1 to 9:1)] to give a colorless oil; yield: 20.0 mg (84%, 27.7 μmol, α-form only); [α]_D ²⁴ +34.5 (c 1.47, CHCl₃). IR (ATR): 3063, 3024, 2922, 2853, 1647, 1452, 1323, 1071, 772 cm^–1. ¹H NMR (400 MHz, CDCl₃, 24 °C): δ = 7.46–7.13 (m, 16 H), 7.06 (dd, J = 6.4, 2.8 Hz, 2 H), 5.66 (s, 1 H), 5.22 (s, 1 H), 4.85 (d, J = 3.4 Hz, 1 H), 4.58 (d, J = 10.1 Hz, 1 H), 4.51 (d, J = 11.2 Hz, 1 H), 4.40 (d, J = 11.2 Hz, 1 H), 4.35 (d, J = 11.9 Hz, 1 H), 4.27 (d, J = 10.1 Hz, 1 H), 4.25 (d, J = 14.2 Hz, 1 H), 4.20 (d, J = 11.9 Hz, 1 H), 4.18 (d, J = 14.2 Hz, 1 H), 4.13 (dd, J = 6.6, 3.7 Hz, 1 H), 4.01 (dd, J = 6.6, 3.7 Hz, 1 H), 3.95 (ddd, J = 6.6, 3.7, 2.3 Hz, 1 H), 3.77 (dd, J = 10.7, 3.7 Hz, 1 H), 3.69 (dd, J = 6.6, 3.4 Hz, 1 H), 3.67 (dd, J = 10.7, 2.3 Hz, 1 H), 3.47 (dd, J = 9.4, 6.6 Hz, 1 H), 3.11 (dd, J = 9.4, 6.6 Hz, 1 H), 3.04–2.84 (m, 4 H), 1.72–1.53 (m, 6 H), 1.22–1.01 (m, 3 H), 0.90–0.78 (m, 2 H). ¹³C NMR (101 MHz, CDCl₃, 24 °C): δ = 141.8, 141.7, 140.3, 138.6, 136.2, 135.7, 133.0, 132.5 (2 C), 131.5, 131.0, 129.2 (2 C), 129.1, 129.0, 128.7, 128.4, 128.2 (2 C), 127.9 (2 C), 127.7, 127.4, 126.3, 126.2, 116.5, 96.6, 78.9, 75.1, 74.1, 72.9, 72.9, 72.5, 72.1, 71.5, 69.7, 66.4, 37.9, 33.5, 33.4, 30.1 (2 C), 26.7, 26.0, 25.9. HRMS (ESI): m/z [M + Na]⁺ calcd for C₄₅H₅₂NaO₆S: 743.3382; found: 743.3379.
• 15 Application of the established conditions to phenylsulfanyl 3,4,6-O-tribenzyl-2-O-proparygyl-β-d-glucopyranose resulted in almost no reaction, indicating that the presence of the EDB group is essential for this glycosylation reaction.
• 16 See the Supporting Information (SI-8) for the yields of 24 and 25. In cases when 13 was recovered, its yield is also reported.
• 17a Kaeothip S, Demchenko AV. J. Org. Chem. 2011; 76: 7388
• 17b Kanie O, Ito Y, Ogawa T. J. Am. Chem. Soc. 1994; 116: 12073