BORON TRI BROMIDE

Obtained by demethylation of 4-(2-meth-oxybenzoyl)-benzonitrile with boron tri-bromide in methylene chloride at 0° [1484],... 

Obtained (by-product) by reaction of boron tri-bromide (4 equiv.) with 2,4-bis(benzyloxy)-5-(3-hydroxy-3-methyl-butynyl)acetophenone in methylene chloride for 5 min at 0° (18%) [3432]. 

Boron tris (trifluoromethanesulfonate) was first prepared by Engelbrecht and Tschager in trifluoromethanesulfonic acid solution vide infra) as a conjugate acid system. Olah and co-workers have isolated B(OS02CF3)3 in pure form by treating boron trihalides (chlorides, bromides) with 3 equiv of triflic acid in Freon 113 or SO2CIF solution. 

CO—- Preparation by demethylation of 2 -chloro-2,5-dimethoxy-3-methylbenzophenone with boron tri-OH bromide in methylene chloride at 0° (76%) [1251]. 

CF3)2C NH BF3, boron tri-chloride and -bromide have been found to interact with an equimolar amount of perfluoroisopropylidenimine at —15 to +20°C to give the aminoboranes (CT 3)2CX NH-BX2 (X = Cl or Br) hydrolysis of the trichloro-compound cleaves the B—N bond with the formation of the amine (CF3)2CC1NH2, a solid which readily decomposes at room temperature to hydrogen chloride and the parent imine. The ot-bromo-analogue (20) of this new amine has been obtained by treatment of diphenyl-boron bromide with an excess of hexafluoroisopropylidenimine ... 

Glycosylation of 3-amino-5(7)//-[l,2,4]triazolo[4,3-3] l,2,4 triazole 17 with 1-O-acetyl- 2,3,5-tri-O-benzoyl-D-ribo-furanose 18 or 2,3,5-tri-O-benzoyl-D-ribofuranosyl bromide 19 can be selective or nonselective, depending on the reaction conditions (Scheme 1). In the presence of trimethylsilyl triflate or boron trifluoride etherate, the... 

Alcohols t-Butyldiphenylchlorosilane, 2-Benzyloxy-l-propene. Bis(iso-propylthio)boron bromide. t-Butylmethox-yphenylsilyl bromide. 2,3-Dichloro-5,6-di-cyano-l,4-benzoquinone. Mercury(II) chloride.4,4, 4 -Tris(4,5-dichlorophthalam-idoltrityl bromide. Tetramethylguanidine. Aldehydes Lithium moipolide. Organotitan-ium compounds. 

ALDOL CONDENSATION (+)-(R)-l-Amino-2- methoxymethyl)pyrrolidine. Boron trichloride. Dialkylboron tri-fluoromethanesulfonates. Dibenzyl-ammonium trifluoroacetate. Di- -butylboryl trifluoromethanesulfonate. Dichlorodiethylaminoborane. Diiso-propylaluminum phenoxide. Diisopropyl-aminomagnesium bromide. Lithium diisopropylamide. Morpholine-Camphoric acid. Proline. 

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