Sodium diphenylborinates

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). 

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). 

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