Boronic fluoride complexation

Acetylcyclohexanone. Method A. Place a mixture of 24-6 g. of cyclohexanone (regenerated from the bisulphite compound) and 61 g. (47 5 ml.) of A.R. acetic anhydride in a 500 ml. three-necked flask, fitted with an efficient sealed stirrer, a gas inlet tube reaching to within 1-2 cm. of the surface of the liquid combined with a thermometer immersed in the liquid (compare Fig. II, 7, 12, 6), and (in the third neck) a gas outlet tube leading to an alkali or water trap (Fig. II, 8, 1). Immerse the flask in a bath of Dry Ice - acetone, stir the mixture vigorously and pass commercial boron trifluoride (via an empty wash bottle and then through 95 per cent, sulphuric acid) as fast as possible (10-20 minutes) until the mixture, kept at 0-10°, is saturated (copious evolution of white fumes when the outlet tube is disconnected from the trap). Replace the Dry Ice-acetone bath by an ice bath and pass the gas in at a slower rate to ensure maximum absorption. Stir for 3 6 hours whilst allowing the ice bath to attain room temperature slowly. Pour the reaction mixture into a solution of 136 g. of hydrated sodium acetate in 250 ml. of water, reflux for 60 minutes (or until the boron fluoride complexes are hydrolysed), cool in ice and extract with three 50 ml. portions of petroleum ether, b.p. 40-60° (1), wash the combined extracts free of acid with sodium bicarbonate solution, dry over anhydrous calcium sulphate, remove the solvent by... 

The behavior of 2-boron fluoride etherate under anhydrous conditions has also been examined in some detail.4 From thiB reaction a crystalline boron fluoride complex was obtained which was spectroscopically characterised as that of the ritf-isomer (XXVII) of A-fert-butylbenzaldoxime. On standing or recrystaUisation from solvent this isomer was converted to the [Pg.326]

Paushkin and Topchiev also used H3P()4-BF3 at room temperature to alkylate benzene with olefins (287,402). For alkylation of benzene with alcohols, temperatures of 90-97° and a feed mole ratio of 0.5 alcohol 1.0 benzene 0.5 catalyst were recommended (394). In a recent study (400a) these authors supplemented their previously published views (396) concerning the properties of boron fluoride complexes with phosphoric acid, alcohols, and sulfuric acid as catalysts. Data on the electroconductivity of these catalysts was correlated with their activity in alkylation of isobutane and it was concluded (400a) that the acid ion concentration did not affect the alkylation or polymerization reactions over these catalysts, and therefore the carbonium ion mechanism was not applicable. 

The high electron dennty of the oxygert atom iti ox nes is favoFaUe to the formation of addition compounds with Lewis acids. Trimethylene oxide has been obeerved to form an iodine complex a hydrate and two dinitrogen tetroxide adducts, one m mole ratio 1 1 and the other 2 The boron fluoride complex is unstable,... 

Startg. r/5-2-aryl-3-aroylaziridine-boron fluoride complex and methyl thiocyanate heated in a sealed ampule under argon at 90° for 0.5-1 h product. Y 73%. F.e.s. V.A. Konovalov et al., Khim. Geterotsikl. Soedin. 1988, 1484-8. 

To prevent decomposition of boron fluoride complexes at 973 K, accompanied by formation of gaseous BF3 [6], to the melt were added F-ions (NaF, KF). 

Cross-linking can proceed through a number of mechanisms. Tertiary amines and boron fluoride complexes catalyse homopolymerization (Reaction 14) ... 

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