Double Protonation of Amino-Substituted Pyridine and Pyrimidine Tungsten Complexes: Friedel鈥揅rafts-like Coupling to Aromatic Heterocycles

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• 作者：Jared A. Pienkos ; Anne T. Knisely ; Brianna L. MacLeod ; Jeffery T. Myers ; Philip J. Shivokevich ; Victor Teran ; Michal Sabat ; William H. Myers ; W. Dean Harman
• 刊名：Organometallics
• 出版年：2014
• 出版时间：October 13, 2014
• 年：2014
• 卷：33
• 期：19
• 页码：5464-5469
• 全文大小：274K
• ISSN：1520-6041

文摘

2-(Dimethylamino)pyridine (2-DMAP) and 2-(dimethylamino)pyrimidine derivatives form 畏²-bound complexes with the dearomatization agent {TpW(NO)(PMe₃)} that are each capable of undergoing a double protonation. In the case of 2-DMAP, the resulting 蟺-allyl species reacts with the 伪-carbon of thiophene or 2-methylfuran, thereby coupling the heterocyclic rings. In the case of the thiophene-derived product, subsequent oxidative decomplexation using ceric ammonium nitrate affords a novel organic amidine derivative. Examples of tungsten-promoted acetylation and fluorination of the aminopyridine ring are also described.