Synthesis and Physicochemical Properties of C-Borylated Esters Based on the closo-Decaborate Anion

The interaction of the monocarbonyl derivative of the closo-decaborate anion [2-B10H9CO](-) with O-nucleophiles has been considered. It has been found that primary, secondary, and tertiary alcohols can enter the addition reaction. It has been shown that the C-O bond is extremely labile in the obtained closo-borate derivatives of the general formula [2-B10H9COOR](2-), and upon heating, its cleavage occurs to form the starting [2-B10H9CO](-). In acidic aqueous solutions, hydrolysis of borylated esters occurs to form a carboxylate derivative of the general formula [2-B10H9COOH](2-). All the derivatives obtained have been isolated and characterized by IR as well as H-1, B-11, and C-13 NMR spectroscopies.