Shu Qiao, Wen-An Ma, Zhong‐Xia Wang
Jul 15, 2011
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Influential Citations
21
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Journal
Journal of Organometallic Chemistry
Abstract
Abstract Reaction of quinolin-8-amine with 1H-pyrrole-2-carbaldehyde or 5-tert-butyl-1H-pyrrole-2-carbaldehyde catalyzed by HCO2H forms N-((1H-pyrrol-2-yl)methylene)quinolin-8-amine (≡ HL, 3a) or N-((5-tert-butyl-1H-pyrrol-2-yl)methylene)quinolin-8-amine (≡ HL′, 3b). Treatment of 3a and 3b respectively with AlMe3 or AlEt3 in toluene affords corresponding aluminum complexes LAlMe2 (4a), L′AlMe2 (4b) and LAlEt2 (4c). Reaction of 3a and 3b with an equivalent of ZnEt2 in toluene generates L2Zn and L′2Zn, respectively. A related compound N-((1H-pyrrol-2-yl)methylene)-2-(3,5-dimethyl-1H-pyrazol-1-yl)benzenamine (≡ HL″, 7) was prepared by reaction of 2-(3,5-dimethyl-1H-pyrazol-1-yl)benzenamine with 1H-pyrrole-2-carbaldehyde in the presence of HCO2H. Reaction of 7 with AlMe3 gives L″2AlMe (8), and with ZnEt2 yields L″2Zn (9). All new compounds were characterized by NMR spectroscopy and elemental analysis. The structures of complexes 4b, 5b and 8 were additionally characterized by single crystal X-ray diffraction analyses. Complexes 4a–4c, and 8 were proved to be active catalysts for the ring-opening polymerization (ROP) of ɛ-caprolactone (ɛ-CL) in the presence of BnOH. The kinetic study of the polymerization reactions catalyzed by 4a and 8 was performed.