Rearrangements of N-Heterocyclic Carbenes of Pyrazole to 4-Aminoquinolines and Benzoquinolines
作者:Andrij Dreger、Rafael Cisneros Camuña、Niels Münster、Tibor András Rokob、Imre Pápai、Andreas Schmidt
DOI:10.1002/ejoc.201000507
日期:2010.8
pyrazolium salts, formed by quaternization of pyrazoles with benzyl halides or long-chain alkyl halides, deprotonate to pyrazol-3-ylidenes that undergo a sequence of ring-opening, ring-closure, and tautomerization to new substituted 4-aminoquinolines. Similarly, 1-naphthyl-substituted pyrazolium-3-carboxylates decarboxylate on heating in toluene to give benzoquinolines in excellent yields by an analogous reaction