Regioselective Nucleophilic Addition to Pyridinium Salts: A New Route to Substituted Dihydropyridones
作者:Timothy J. Donohoe、Matthew J. Connolly、Lesley Walton
DOI:10.1021/ol902402v
日期:2009.12.3
The regioselective addition of nucleophiles to pyridinium salts generates an intermediate enol-ether, which can be hydrolyzed in situ to provide a range of dihydropyridones. Certain Grignards have shown inherent differences in the regioselectivity of addition to these salts, and this difference can be tuned to give single regioisomeric addition products. The dihydropyridone products can be further
The ammonia-free partial reduction of substituted pyridinium salts
作者:Timothy J. Donohoe、Dale J. Johnson、Laura H. Mace、Rhian E. Thomas、Jessica Y. K. Chiu、Jason S. Rodrigues、Richard G. Compton、Craig E. Banks、Peter Tomcik、Mark J. Bamford、Osamu Ichihara
DOI:10.1039/b517462g
日期:——
This paper reports a study into the partial reduction of N-alkylpyridinium salts together with subsequent elaboration of the intermediates thus produced. Activation of a pyridinium salt by placing an ester group at C-2, allows the addition of two electrons to give a synthetically versatile enolate intermediate which can be trapped with a variety of electrophiles. Furthermore, the presence of a 4-methoxy