DOI: 10.14469/hpc/14727 Metadata

Created: 2024-11-01 15:33

Last modified: 2025-02-09 17:04

Author: Henry Rzepa

License: Creative Commons: Public Domain Dedication 1.0

Funding: (none given)

Description

Procedure A (from BCl3): In a flame dried Schlenk flask, under an atmosphere of argon, 3,4,5-trifluorophenol (7.26 g, 49 mmol) was dissolved in 30 ml anhydrous dichloromethane and cooled to -40 °C (precipitates). Boron trichloride solution (0.82 M in DCM, 20 ml, 16.333 mmol) (care, HCl evolution) was added dropwise and the reaction became homogenous. After 30 minutes the reaction was warmed to 0 °C with an ice/water bath (HCl evolves on warming), stirred for 30 minutes and warmed to room temperature. After 1 hour the reaction was concentrated under vacuum and the residue redissolved by warming in a mix of anhydrous pentane (10 ml) and DCM (4 ml), then cooled to -20 °C overnight, producing a crop of white crystals. The crystals were washed with pentane (1 ml) and dried under reduced pressure. Yield = 4.8 g, 10.6 mmol, 65%. Procedure B (from BH3.SMe2): Under an atmosphere of argon in a flame dried 2 neck round bottom flask equipped with a reflux condenser, 3,4,5-trifluorophenol (10 g, 68 mmol), was dissolved in 15 ml anhydrous diethyl ether. The solution was cooled to 0 °C, and borane dimethylsulfide (2.6 ml, 2.6 mmol) was added dropwise and stirred for 30 minutes, after which the reaction was heated to reflux overnight. The solution was transferred to a Schlenk flask and concentrated under reduced pressure. Recrystallisation of the residue is typically more difficult than using procedure A, presumably due to residual dimethyl sulfide or borane species, and works most effectively using pentane/ether mixes (2:1). Yield 5.5g, 12.2 mmol, 47%. 1H NMR (500 MHz, CDCl3) δ (ppm) = 6.77 (m, 6H) 13C{1H}NMR (126 MHz, CDCl3) δ (ppm) = 151.3 (ddd, JC-F = 250.1, 10.5, 5.5 Hz), 146.9 (td, JC-F = 4.0, 11.9 Hz), 137.4 (dt, JC-F = 248.6, 15.3, Hz), 105.3 (m) 11B NMR (128 MHz, CDCl3) δ (ppm) = 15.6 (s) 19F NMR (376 MHz, CDCl3) δ (ppm) = -132.66 (d, J = 21 Hz), -165.51 (t, J = 21 Hz). HRMS: [C18H6BO3F9 + OMe]- : Expect 483.05 observe 483.05 νmax (solid/cm-1): 3090, 1625, 1520, 1453 tris(2,2,3,3,4,4,5,5-octafluoropentyl) borate

Member of collection / collaboration

DOI	Description
10.14469/hpc/14865	NMR Data for compound 37. Borate Catalysts

Members

DOI	Description
10.14469/hpc/14818	NMR data for 37b. tris(3,4,5-trifluorophenyl) borate. 19F
10.14469/hpc/14820	NMR data for 37b. tris(3,4,5-trifluorophenyl) borate. 11B
10.14469/hpc/14817	NMR data for 37b. tris(3,4,5-trifluorophenyl) borate. 1H
10.14469/hpc/14819	NMR data for 37b. tris(3,4,5-trifluorophenyl) borate. 13C

Subject Keywords

Keyword	Value
Inchi	InChI=1S/C18H6BF9O3/c20-10-1-7(2-11(21)16(10)26)29-19(30-8-3-12(22)17(27)13(23)4-8)31-9-5-14(24)18(28)15(25)6-9/h1-6H
Inchikey	MSUHVZVNRVWSCG-UHFFFAOYSA-N

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