Catalytic Decarboxylative Glycosylation Promoted by Hafnium(IV) ­Trifluoromethanesulfonate: β-Selective Glycosylation via a Mixed Carbonate of an Acyl-Protected Donor Sugar

Abstract

Acyl-protected mixed carbonates were effectively decarboxylated by catalytic amounts (2-5 mol%) of hafnium(IV) tri­fluoromethanesulfonate in dichloromethane at room temperature to give the corresponding β-glycosides in excellent yields.

glycosylations - glycosides - Lewis acids - mixed carbonates - decarboxylation

References

1

Present address: School of Pharmaceutical Sciences, Kitasato University, Shirokane, Minato-ku, Tokyo 108-8641, Japan.

Reviews:

2a Schmidt RR. Angew. Chem., Int. Ed. Engl.  1986,  25:  212 

2b Toshima K. Tatsuta K. Chem. Rev.  1993,  93:  1503 

2c Boons G.-J. Tetrahedron  1996,  52:  1095 

2d Schmidt RR. Comprehensive Organic Chemistry   Vol. 6:  Pergamon Press; Oxford: 1991.  p.33-64  

3a Hashimoto S. Hayashi M. Noyori R. Tetrahedron Lett.  1984,  25:  1379 

3b Mukaiyama T. Shimpuku T. Takashima T. Kobayashi S. Chem. Lett.  1989,  145 

3c Mukaiyama T. Takashima T. Katsurada M. Aizawa H. Chem. Lett.  1991,  533 

3d Mukaiyama T. Katsurada M. Takashima T. Chem. Lett.  1991,  985 

3e Charette AB. Marcoux J.-F. Côté B. Tetrahedron Lett.  1991,  32:  7215 

3f Mukaiyama T. Matsubara K. Chem. Lett.  1992,  1041 

3g Matsubara K. Sasaki T. Mukaiyama T. Chem. Lett.  1993,  1373 

3h Matsubara K. Mukaiyama T. Chem. Lett.  1993,  2145 

3i Shinomura N. Saitoh M. Mukaiyama T. Chem. Lett.  1994,  433 

3j Mukaiyama T. Ishikawa T. Uchiro H. Chem. Lett.  1997,  389 

4 Nashed EM. Glaudemans CPJ. J. Org. Chem.  1989,  54:  6116 

5a Bochkov AF. Kochetkov NK. Carbohydr. Res.  1975,  39:  355 

5b Kochetkov NK. Backinowsky LV. Tsvetkov YE. Tetrahedron Lett.  1977,  3681 

5c Betaneli VI. Ovchinnikov MV. Backinowsky LV. Kochetkov NK. Carbohydr. Res.  1979,  76:  252 

5d Kochetkov NK. Klimov EM. Malysheva NN. Tetrahedron Lett.  1989,  30:  5459 

5e Kochetkov NK. Nepogod’ev SA. Backinowsky LV. Tetrahedron  1990,  46:  139 

5f Kochetkov NK. Klimov EM. Malysheva NN. Demchenko AV. Carbohydr. Res.  1991,  212:  77 

5g Kochetkov NK. Malysheva NN. Klimov EM. Demchenko AV. Tetrahedron Lett.  1992,  33:  381 

6a Iimori T. Shibazaki T. Ikegami S. Tetrahedron Lett.  1996,  37:  2267 

6b Iimori T. Azumaya I. Shibazaki T. Ikegami S. Heterocycles  1997,  46:  221 

6c Azumaya I. Niwa T. Kotani M. Iimori T. Ikegami S. Tetrahedron Lett.  1999,  40:  4683 

7a Inaba S. Yamada M. Yoshino T. Ishido Y. J. Am. Chem. Soc.  1973,  95:  2062 

7b Ishido Y. Inaba S. Matsuno A. Yoshino T. Umezawa H. J. Chem. Soc., Perkin Trans. 1  1977,  1382 

8 Scheffler G. Schmidt RR. Tetrahedron Lett.  1997,  38:  2943 

9a Kobayashi S. Synlett  1994,  689 ; and references therein

9b Kobayashi S. Eur. J. Org. Chem.  1999,  15 ; and references therein

10 Kobayashi S. Hachiya I. Araki M. Ishitani H. Tetrahedron Lett.  1993,  34:  3755 

11a Kanie O. Ito Y. Ogawa T. J. Am. Chem. Soc.  1994,  116:  12073 

11b Kim W.-S. Hosono S. Sasai H. Shibasaki M. Tetrahedron Lett.  1995,  36:  4443 

11c Hosono S. Kim W.-S. Sasai H. Shibasaki M. J. Org. Chem.  1995,  60:  4 

11d Kim W.-S. Sasai H. Shibasaki M. Tetrahedron Lett.  1996,  37:  7797 

11e Yamada H. Imamura K. Takahashi T. Tetrahedron Lett.  1997,  38:  391 

11f Shimizu M. Togo H. Yokoyama M. Synthesis  1998,  799 ; and references therein

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Typical Experimental Procedure for the Decarboxylative Glycosylation: To a solution of a mixed β-carbonate (0.1 mmol) in CH₂Cl₂ (1 mL) with stirring at ambient temperature was added a metal triflate. After the reaction was completed, a saturated solution of NaHCO₃ was added and the mixture was extracted with EtOAc. The organic layer was washed with brine twice, dried over Na₂SO₄, filtered, and evaporated. The crude product was purified by silica gel column chromatography to give the corresponding glycosides.

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Selected analytical data for the compounds 7b, 7c, 8a and 8d are shown. All the other glycosides are also fully characterized.
Compound 7b: [α]_D ²² +10.9 (c 0.50, CHCl₃). ¹H NMR (400 MHz, CDCl₃): δ = 1.11 (s, 9 H), 1.14 (s, 9 H), 1.15 (s, 9 H), 1.24 (s, 9 H), 3.33 (dd, J = 8.9 Hz, 10.1 Hz, 1 H), 3.37 (s, 3 H), 3.47 (dd, J = 3.7 Hz, 9.8 Hz, 1 H), 3.59 (dd, J = 6.4 Hz, 10.7 Hz, 1 H), 3.82 (ddd, J = 1.8 Hz, 6.1 Hz, 9.8 Hz, 1 H), 3.89 (m, 1 H), 3.95-4.04 (m, 3 H), 4.11 (dd, J = 6.4 Hz, 11.0 Hz, 1 H), 4.45 (anomeric, d, J = 7.9 Hz, 1 H), 4.54 (d, J = 3.7 Hz, 1 H), 4.57 (d, J = 11.3 Hz, 1 H), 4.65 (d, J = 12.2 Hz, 1 H), 4.77 (d, J = 11.9 Hz, 1 H), 4.79 (d, J = 10.7 Hz, 1 H), 4.87 (d, J = 11.0 Hz, 1 H), 4.98 (d, J = 11.0 Hz, 1 H), 5.05 (dd, J = 3.4 Hz, 10.4 Hz, 1 H), 5.23 (dd, J = 7.9 Hz, 10.4 Hz, 1 H), 5.37 (dd, J = 0.9 Hz, 3.4 Hz, 1 H), 7.25-7.36 (m, 15 H) ppm. ¹³C NMR (100 MHz, CDCl₃): δ = 27.0, 27.1, 27.1, 38.7, 38.7, 38.7, 39.0, 55.2, 61.1, 66.7, 68.4, 68.6, 69.9, 71.0, 71.1, 73.2, 74.8, 75.6, 76.7, 77.0, 77.2, 77.3, 78.1, 79.9, 81.9, 97.7, 101.5, 127.5, 127.7, 127.8, 127.9, 128.1, 128.3, 128.4, 138.1, 138.2, 138.8, 176.5, 176.9, 177.3, 177.8 ppm. MS (FAB-NBA + NaI): m/z = 986 (M + Na⁺ + 1). HRMS (FAB-NBA + NaI): calcd for C₅₄H₇₄O₁₅Na: 985.4925; found: 985.4937.
Compound 7c: [α]_D ²² -1.3 (c 0.50, CHCl₃). ¹H NMR (400 MHz, CDCl₃): δ = 1.07 (s, 9 H), 1.10 (s, 9 H), 1.14 (s, 9 H), 121 (s, 9 H), 3.37 (s, 3 H), 3.41 (dd, J = 3.7 Hz, 9.5 Hz, 1 H), 3.50-3.56 (m, 2 H), 3.60 (dd, J = 1.8 Hz, 10.4 Hz, 1 H), 3.78-3.84 (m, 2 H), 3.93-4.03 (m, 3 H), 4.22 (anomeric, d, J = 7.9 Hz, 1 H), 4.34 (d, J = 11.9 Hz, 1 H), 4.59 (d, J = 3.7 Hz, 1 H), 4.60 (d, J = 12.5 Hz, 1 H), 4.69 (dd, J = 3.4 Hz, 10.4 Hz, 1 H), 4.70 (d, J = 11.3 Hz, 1 H), 4.74 (d, J = 12.5 Hz, 1 H), 4.82 (d, J = 12.2 Hz, 1 H), 5.07 (d, J = 11.0 Hz, 1 H), 5.10 (dd, J = 7.9 Hz, 10.4 Hz, 1 H), 5.22 (dd, J = 0.6 Hz, 3.1 Hz, 1 H), 7.19-7.45 (m, 15 H) ppm. ¹³C NMR (100 MHz, CDCl₃): δ = 27.0, 27.1, 27.1, 27.2, 38.7, 38.7, 38.9, 55.4, 61.1, 67.0, 67.6, 69.3, 69.6, 70.6, 71.3, 73.5, 73.7, 75.1, 75.3, 76.7, 77.0, 77.2, 77.3, 78.0, 79.7, 98.7, 99.4, 127.1, 127.3, 127.7, 128.0, 128.1, 128.3, 128.5, 128.6, 128.8, 137.5, 138.4, 139.4, 176.3, 176.9, 177.2, 177.8 ppm. MS (FAB-NBA + NaI): m/z = 986 (M + Na⁺ + 1). HRMS (FAB-NBA + NaI): calcd for C₅₄H₇₄O₁₅Na: 985.4926; found: 985.4915.
Compound 8a: [α]_D ²³ +11.8 (c 1.00, CHCl₃). ¹H NMR (400 MHz, CDCl₃): δ = 1.00-1.90 (m, 10 H), 1.87 (s, 3 H), 2.03 (s, 9 H), 2.11 (s, 3 H), 3.60 (m, 1 H), 3.86 (ddd, J = 2.4 Hz, 4.9 Hz, 10.1 Hz, 1 H), 4.16 (dd, J = 2.3 Hz, 10.9 Hz, 1 H), 4.37 (m, 2 H), 5.17 (t, J = 9.8 Hz, 1 H), 5.46 (anomeric, d, J = 8.2 Hz, 1 H), 5.80 (dd, J = 8.9 Hz, 10.7 Hz, 1 H), 7.74 (m, 2 H), 7.86 (m, 2 H) ppm. ¹³C NMR (100 MHz, CDCl₃): δ = 14.1, 20.4, 20.6, 20.7, 23.5, 23.7, 25.3, 31.4, 33.1, 54.8, 60.3, 62.2, 69.2, 70.8, 71.6, 76.7, 77.0, 77.3, 77.6, 96.6, 123.5, 131.4, 134.2, 169.4, 170.1, 170.7 ppm. MS (FAB-NBA + NaI): m/z = 541 (M + Na⁺). HRMS (FAB-NBA + NaI): calcd for C₂₆H₃₁O₁₀Na: 540.1846; found: 540.1840.
Compound 8d: [α]_D ²² -23.7 (c 0.37,CHCl₃). ¹H NMR (400 MHz, CDCl₃): δ = 1.87 (s, 3 H), 2.01 (s, 3 H), 2.05 (s, 3 H), 3.18 (s, 3 H), 3.37-3.46 (m, 2 H), 3.66 (dd, J = 3.8 Hz, 10.1 Hz, 1 H), 3.81-3.85 (m, 2 H), 3.91 (ddd, J = 2.5 Hz, 4.9 Hz, 10.1 Hz, 1 H), 3.98 (br, 1 H), 4.08 (dd, J = 2.9 Hz, 10.4 Hz, 1 H), 4.19 (dd, J = 2.5 Hz, 12.5 Hz, 1 H), 4.19 (t, J = 12.5 Hz, 1 H), 4.22 (d, J = 3.7 Hz, 1 H), 4.34 (dd, J = 5.2 Hz, 12.2 Hz, 1 H), 4.34 (d, J = 12.2 Hz, 1 H), 4.41 (dd, J = 8.7 Hz, 10.8 Hz, 1 H), 4.43 (d, J = 11.3 Hz, 1 H), 4.54 (d, J = 11.6 Hz, 1 H), 4.92 (d, J = 11.6 Hz, 1 H), 5.18 (dd, J = 9.2 Hz, 10.1 Hz, 1 H), 5.65 (anomeric, d, J = 8.2 Hz, 1 H), 5.93 (dd, J = 9.2 Hz, 10.7 Hz, 1 H), 6.99-7.36 (m, 15 H), 7.61-7.88 (m, 4 H) ppm. ¹³C NMR (100 MHz, CDCl₃): δ = 14.2, 20.4, 20.6, 20.6, 21.0, 29.6, 55.1, 55.1, 60.3, 62.0, 68.9, 69.1, 69.1, 70.4, 71.5, 73.2, 73.4, 74.9, 75.8, 76.7, 77.0, 77.2, 77.3, 78.8, 98.5, 99.4, 123.5, 123.6, 127.5, 127.6, 127.6, 127.6, 127.7, 127.7, 127.7, 127.8, 127.8, 128.1, 128.2, 128.2, 128.3, 128.3, 128.4, 128.4, 128.4, 128.5, 128.6, 131.5, 134.2, 134.2, 138.0, 138.3, 138.8, 167.3, 169.6, 170.0, 170.5 ppm. MS (FAB-NBA + NaI): m/z = 905 (M + Na⁺). HRMS (FAB-NBA + NaI): calcd for C₄₈H₅₁O₁₅NNa: 904.3157; found: 904.3129.

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Competition Experiment: To a solution of 9 (32.4 mg, 0.050 mmol) and 10 (33.3 mg, 0.050 mmol) in CH₂Cl₂ (1 mL) with stirring at ambient temperature was added Hf(OTf)₄ (1.3 mg, 0.02 equiv). After 20 min, a saturated solution of NaHCO₃ was added and the mixture was extracted with EtOAc. The organic layer was washed with brine twice, dried with Na₂SO₄, filtered, and evaporated. The crude product was carefully purified by silica gel column chromatography so as not to lose any of the generated glycosides. The mixture of glycosides and the authentic glycosides were analyzed by HPLC (eluent: 0.5% IPA in n-hexane).

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Preparation of Authentic Glycosides for the Competition Experiment: Authentic glycosides (13-16) were synthesized by decarboxylative glycosylation promoted by trimethylsilyl trifluoromethanesulfonate [5c] from the corresponding mixed β-carbonates (9-12).

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Evolution of carbon dioxide (90% yield) was confirmed by measuring the volume of generated gas with a buret filled with water. Spaces in the reaction vessel and the buret were dynamically separated by silicon oil that cannot dissolve carbon dioxide.