New perspectives for boronic esters in macrocyclic chemistry

In the present contribution a tetrameric macrocyclic compound derived from 2,6-pyridinedimethanol and 3-nitrophenyl boronic acid, as well as 10 new di meric boronates prepared from 2-salicylideneaminoethanol and different aryl boronic acids such as a 2-methylphenyl-, 3-methylphenyl-, 4-methylphenyl-, 3-methoxyphenyl-, 4-methoxyphenyl-, 3-chlorophenyl-, 4-chlorophenyl-, 3-ni trophenyl-, 3-trifluoromethylphenyl- and 4-fluorophenylboronic acid are des cribed. The tetrameric and three of the dimeric structures have been analyz ed by X-ray crystallography, and a series of parameters such as bond length , bond angles, deviation of the boron atom from the boronate mean plane and intermolecular interactions are discussed. (C) 1999 Elsevier Science S.A. All rights reserved.