ChemInform Abstract: Boron Compounds. Part 73. Novel Chelated Organodiboroxanes and Organoboroxins from Triorganoboroxins and Enolizable 1,3-Diketones.

ChemInform Abstract

Trialkylboroxins (I) react with enolizable 1,3-diketones (II) at 20°C with fast degradation of the boroxin rings to give the monochelated diboroxanes (III). The solid Compounds (III) with H-bridged bicyclic structures are in equilibrium with partially ring-opened species in solution (′H, "B, "C, and ′70 NMR data). At higher temp. the double Chelated diboroxanes (IV) are obtained. (Ic) reacts with (II) at 140°C with slow protolysis of the B-phenyl residu-es to form the singly and doubly Chelated boroxins (V) and (VI). The Compounds (IV), (V) and (VI) are stable up to 200°C. The molecular structures of (IVb) (exact data not given) and (Va) (space group Pca2, with Z=4) are qetermined by X-ray analysis.