Dicyclohexylboron trifluoromethanesulfonate (CAS no.: ), which could be called as Dicyclohexyl(trifluoromethanesulfonyloxy)borane, could be produced through the following synthetic routes.

Dicyclohexylboron trifluoromethanesulfonate. 2 An oven-dried, 250-mL, round-bottomed flask containing a stir bar and capped with a rubber septum is charged with cyclohexene (33.4 mL, 0.33 mol) and dry diethyl ether (100 mL), and kept at 0°C under nitrogen. Borane-dimethyl sulfide complex (16.6 mL, 0.16 mol) is added dropwise during 30 min with stirring. The reaction mixture is stirred for 3 hr at 0°C, then the solid is allowed to settle without stirring. The supernatant organic solution is removed as much as possible by syringe, and the residual solid is dried under reduced pressure to give dicyclohexylborane (26.3-28.3 g, 92-99% yield), which is used without purification for the preparation of the triflate.

The solid is suspended in 100 mL of dry hexane and trifluoromethanesulfonic acid (24.0 g, 0.16 mol) is added dropwise via a glass syringe over 30 min with constant stirring, during which time vigorous gas evolution occurs; the solid gradually dissolves, and the solution develops a yellow-orange color. Stirring is continued at room temperature for 1 hr, then the reaction mixture is left for 1-2 hr without stirring. A semi-solid phase separates and the top layer is transferred via cannula into a dry, 250 mL round-bottomed flask. The flask is placed in a -20°C freezer for 36 hr. Large crystals form and the mother liquor is transferred via cannula to another dry, 100-mL, round-bottomed flask. The crystals are dried under reduced pressure at 0°C for 5 hr giving 40.8 g (78%) of dicyclohexylboron trifluoromethanesulfonate . The mother liquors are concentrated to dryness under nitrogen (N₂) using a rotary evaporator. The residue is redissolved in 20 mL of dry hexane and crystallized in a -20°C freezer as described above to give an additional 7 g of product. The total yield of dicyclohexylboron trifluoromethanesulfonate is 47.8 g (92%). The isolated crystals are dissolved in hexane in a graduated cylinder equipped with a ground glass joint and a stopcock-equipped syringe inlet to make a 1 M stock solution.