Diphenylborinic acid

A/-Diphenylborinic Acid Derivative, 593 A/-Diethylborinic Acid Derivative, 593 A/-Difluoroborinic Acid Derivative, 594... 

A benzo derivative of l,2-dihydro-2,4,l-diazaborine (131) is known. Thus reaction of 2-aminobenzeneboronic acid with cyanic acid gave compound (146). Some non-hydroxyl-ated compounds were prepared from (V,(V -diphenylamidines and trialkylboranes or the n-butyl ester of diphenylborinic acid (Scheme 28) (79IZV174). 

At pH 10, diphenylborinic acid gives a tetrahedral anion that complexes with various diol systems, and thus it can be used in electrophoresis like borate.109 In a more detailed study of such complexing,110 diols were examined by 13C-n.m.r. spectroscopy, before and after addition of sodium diphenylborinate, and complexes were detected, and their spectra observed, for a variety of carbohydrate derivatives. 1,2-Diol groupings in acyclic and cis-cyclic compounds, 1,3-related diols at C-4,C-6 of hexopyranosides, the 3,5-diols of glucofuranoses, and 2,4-diols of the anomeric methyl 3,6-anhydro-D-glucopyranosides were all found to react. No interaction occurred with l,6-anhydro-/3-D-glucopyranose (compare Section V,2). 

We have also developed a new catalytic system for aldol reactions in water. The reaction of benzaldehyde with silyl enol ether 2 was catalysed by a combination of diphenylborinic acid (PhjBOH), benzoic acid and SDS in water to give the aldol adduct in high yield with high syn/anti ratio (Equation (6)) [30,31]. All of the three components in the catalyst combination were indispensable for the high yield and selectivity. This... 

The hydrolysis of salicylaldehyde imines is catalyzed by boric acid, substituted arylboronic acids, and diphenylborinic acid. The effects of different substituted phenyl-boronic acids on the rate of hydrolysis at pH 6.0 has been studied by Rao and Philipp [168]. The second-order rate constants, are higher for phenylboronic... 

W-Diphenylborinic Acid Derivative, 837 W-Diethylborinic Acid Derivative, 837... 

Diphenylborane generated by reduction of diphenylborinic acid ester redistributes rapidly to the mixture of PhjB and 1,2-diphenyldiborane ... 

MeOH (4 2 1). Chromatograms were evaluated under UV light at 254 and 365 nm to detect the presence of flavonoids. TLC was additionally sprayed with a diphenylborinic acid ethanolamine/polyethylene glycol reagent. Apigenin, chlorogenic acid, genkwanin, luteolin, quercetin and rutin were used as markers (purchased from Extrasynthese, France). 

Diphenylborinic acid (PhjBOH) catalyses addition of an isocyanide (CN-R ) to an aldehyde (R -CHO) to give an a-hydroxyamide [R -CH(OH)CONHR ] in DCM at room temperature one equivalent of water is also required." ... 

In 1993, a tris(pentafluorophenyl)boron was first recognized by Yamamoto and co-workers as a water-tolerant Lewis acid catalyst in the aldol reaction of silyl enol ethers (237). Subsequently, Kobayashi and co-workers developed the first strategy for catalytic generation of boron enolates, employing catalytic amount of diphenylborinic acid (Ph2BOH) to promote the Mukaiyama aldol reaction in the presence of sodium dodecyl sulfate (SDS) (Scheme 59). The authors presumed that the active species of the reactions are boron enolates. Perhaps it is the first example of catalytic use of a boron source in boron enolatemediated diastereoselective aldol reactions (238). 

A soln. of diphenylborinic acid in methanol added to a solution of N-methyl-ephedrine in the same solvent, and coned, to half its volume cis-2,2,5-tri-... 

Ketoximes have been reacted with aliphatic aldehydes and diphenylborinic acid. " a-Hydroxyalkylation at the oxime oxygen is favoured by a bulky substituent in the aldehyde (leading subsequently to a BOCON diphenylboron chelate), while formaldehyde reacts by A-alkylation (giving a COBON chelate). 

Substituted benzeneboronic acids have been evaluated for the gas chromatographic determination of bifunctional compounds (e.g. pinacol, propane-1,3-diamine, butane-l,4-diol). Phenylboronic and diphenylborinic acid have... 

Aminoethanolato-lA,0)diphenylboron, lOCI. Diphenylborinic acid 2-aminoethyl ester. Aminoethyl diphenylborinate. Hydroxydiphenylborane ethanolamine [15614-89-8]... 

Diphenyl black base P, see A-00166 Diphenylborinic acid 2-aminoethyl ester, see... 

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