(N-Arylaminomethyl)pyridine-N-oxides: Synthesis and characterization of potential ligand systems and the formation of their N,O-chelate aluminum complexes
摘要:
Pyridine-N-oxide-2-carbaldehyde (4a) was converted to the corresponding imine (5a) by treatment with 2,6-diisopropylaniline. Subsequent reduction with a sodium borohydride gave the corresponding ( N-arylaminomethyl) pyridine-N-oxide derivative (6a). A series of analogous compounds was prepared starting from the respective ( aldimino) quinoline-N-oxide ( 4b) or ( ketimino) pyridine-N-oxide ( 10) systems. Deprotonation of the ( aminomethyl) pyridine-N-oxides resulted in a series of unexpected reactions, such as coupling, internal redox reactions or fragmentation. Eventually, the N,O-chelate aluminum complexes ( 22, 23) derived from the ( aminoethyl) pyridine-N-oxide ligand systems could be obtained by treatment of the respective iminopyridine-N-oxides with trimethylaluminum. Many products were characterized by X-ray diffraction. (C) 2008 Elsevier B. V. All rights reserved.