2-Aminoethyl Diphenylborinate

Used Chemicals

• 2,3,4,6-Tetra-O-acetyl-α-D-glucopyranosyl Bromide (stabilized with CaCO₃) [T1961]
• Methyl α-L-Fucopyranoside [M1051]
• 2-Aminoethyl Diphenylborinate [D0281]
• Silver(I) Oxide
• Acetonitrile

Procedure

To a solution of methyl α-L-fucopyranoside (392 mg, 2.2 mmol, 1.1 equiv), silver(I) oxide (463 mg, 2.0 mmol, 1.0 equiv) and 2-aminoethyl diphenylborinate (45 mg, 0.2 mmol, 10 mol%) in acetonitrile (23 mL) was added 2,3,4,6-tetra-O-acetyl-α-D-glucopyranosyl bromide (822 mg, 2.0 mmol, 1 equiv) at r.t. and the mixture was stirred for 4 hours. The reaction mixture was filtered through celite pad and washed with dichloromethane (30 mL). The solvent was removed under reduced pressure and the residue was purified by column chromatography (ethyl acetate:hexane = 0:1 - 3:1 on silica gel), to give 1 as a white amorphous (914 mg, 90%).

Experimenter’s Comments

The reaction mixture was monitored by TLC (ethyl acetate, R_f = 0.51).
The color of the reaction mixture turned from black to gray as the reaction proceeds.

Analytical Data（Compound 1）

¹H NMR (400 MHz, CDCl₃); δ 5.23 (t, J = 9.5 Hz, 1H), 5.07 (t, J = 9.5 Hz, 1H), 5.04 (dd, J =　9.5, 7.8 Hz, 1H), 4.83 (d, J = 3.8 Hz, 1H), 4.68 (d, J = 7.8 Hz, 1H), 4.25 (dd, J = 12.2, 2.7 Hz, 1H), 4.17 (dd, J = 12.2, 5.1 Hz, 1H), 3.99 (dd, J = 10.0, 3.8 Hz, 1H), 3.95 (brq, J = 6.8 Hz, 1H), 3.83 (dd, J = 10.0, 3.5 Hz, 1H), 3.76 (ddd, J = 10.0, 5.1, 2.7 Hz, 1H), 3.72 (m, 1H), 3.43 (s, 3H), 3.14 (d, J = 3.8 Hz, 1H), 2.27 (brs, 1H), 2.10 (s, 3H), 2.07 (s, 3H), 2.04 (s, 3H), 2.02 (s, 3H), 1.31 (d, J = 6.8 Hz, 3H).

Lead Reference

• Regioselective Activation of Glycosyl Acceptors by a Diarylborinic Acid-Derived Catalyst
• C. Gouliaras, D. Lee, L. Chan, M. S. Taylor, J. Am. Chem. Soc. 2011, 133, 13926.

Other References

• Boronic Acid-Catalyzed Regioselective Koenigs–Knorr-Type Glycosylation
• N. Shimada, T. Sugimoto, M. Noguchi, C. Ohira, Y. Kuwashima, N. Takahashi, N. Sato, K. Makino, J. Org. Chem. 2021, 86, 5973.

References

• 2APB, 2-Aminoethoxydiphenyl Borate, a Membrane-Penetrable Modulator of Ins(1,4,5)P₃-Induced Ca²⁺ Release
  • T. Maruyama, T. Kanaji, S. Nakade, T. Kanno, K. Mikoshiba, J. Biochem. 1997, 122, 498.
• 2-Aminoethoxydiphenyl borate (2-APB) is a reliable blocker of store-operated Ca²⁺ entry but an inconsistent inhibitor of InsP₃-induced Ca²⁺ release
  • M. D. Bootman, T J. Collins, L. Mackenzie, H. L. Roderick, M. J. Berridge, C. M. Peppiatt, FASEB J. 2002, 16, 1145.
• 2-Aminoethoxydiphenyl borate (2-APB) antagonises inositol 1,4,5-trisphosphate-induced calcium release, inhibits calcium pumps and has a use-dependent and slowly reversible action on store-operated calcium entry channels
  • L. Missiaen, G. Callewaert, H. De Smedt, J.B. Parys, Cell Calcium 2001, 29, 111.