Ferroceneboronic acid derivatives

Shinkai and co-workers (Ori and Shinkai, 1995) have recently extended their work using ferroceneboronic acid derivatives to the detection of neutral molecules. A chiral ferroceneboronic acid [101] bearing a tertiary amino group... 

Chiral ferroceneboronic acid derivatives have been synthesized by Ori and tested for chiral electrochemical detection of monosaccharides. The best discrimination was observed for L-sorbitol and L-iditol at pH 7.0 in 0.1 mol dm phosphate buffer solution. Moore and Wayner have explored the redox switching of carbohydrate binding with commercial ferrocene boronic acid. From their detailed investigations, they have determined that binding constants of saccharides with the ferrocenium form are about 2 orders of magnitude greater than those for the ferrocene form. The increased stability is ascribed to the lower pKe of the ferrocenium (5.8) than ferrocene (10.8) boronic acid. 

Chiral ferroceneboronic acid derivatives (- or -h)-60 have been synthesized and tested for chiral electrochemical detection of monosaccharides [138], The best discrimination was observed for L-sorbitol and L-iditol at pH 7.0 in 0.1 mol dm phosphate buffer solution. 

Metalated ferrocenes have served as valuable intermediates for the synthesis of a number of other derivatives. Treatment of lithiated ferrocenes with tributyl borate followed by hydrolysis leads to ferroceneboronic acid (XXXIII) as well as the diboronic acid (73). Ferroceneboronic acid, like benzeneboronic acid, is readily cleaved by cupric bromide or cupric chloride to form the corresponding halo derivatives (XXXIV). Ferrocene-l,l -diboronic acid reacts in the same manner, and either one or two carbon-boron bonds can be cleaved. Further reactions of this type have led to a variety of mixed dihaloferrocenes (73, 75). 

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