New strategy to the synthesis of (N → B) phenyl[N-alkyliminodiacetate-O,O′,N]boranes: The crystal structure of (N → B) phenyl[N-benzyliminodiacetate-O,O′,N]borane, (N → B)phenyl[N-(4-methyl)benzyliminodiacetate-O,O′,N]borane and (N → B) phenyl[N-phenacyliminodiacetate-O,O′,N]borane

A new, mild and friendly method for the synthesis of (N -> B) pheny[N-alkyliminodiacetate-O,O',N]boranes 2-7 is reported. All compounds were identified by H-1, B-11, C-13 NMR and their high resolution mass spectra (HRMS) are reported. The structure of the compounds 2, 4 and 5 were established by single crystal X-ray. Compounds 2 and 4 crystallized with two independent molecules 2A, 2B and 4A, 4B. respectively in the asymmetric unit. These molecular structures established the bicyclic structure showing a N -> B bond length of 1.666 (2) angstrom for 2A, 1.675 (2) angstrom for 2B, 1.675 (3) angstrom for 4A, 1.663 (3) angstrom for 4B and 1.679 (2) angstrom for 5, as well as different torsion angles of the junction, 28.70 (2)degrees (C11-B1-N6-C17) for 2A, 21.50 (2)degrees (C11a-B1a-N6a-C17a) for 2B, 25.76 (0.26)degrees (C11-B1-N6-C17) for 4A, 21.96 (0.28)degrees (C11a-B1a-N6a-C17a) for 4B and -29.22 (0.20)degrees (C5-N1-B1-C13) for 5. (C) 2009 Elsevier Ltd. All rights reserved.