Photogeneration of Benzhydryl Cations by Near-UV Laser Flash Photolysis of Pyridinium Salts
作者:Tobias A. Nigst、Johannes Ammer、Herbert Mayr
DOI:10.1021/jp3049247
日期:2012.8.23
Laser flash irradiation of substituted N-benzhydryl pyridinium salts yields benzhydryl cations (diarylcarbenium ions) and/or benzhydryl radicals (diarylmethyl radicals). The use of 3,4,5-triamino-substituted pyridines as photoleaving groups allowed us to employ the third harmonic of a Nd/YAG laser (355 nm) for the photogeneration of benzhydryl cations. In this way, benzhydryl cations can also be photogenerated
Synthesis and Reactivity of Highly Nucleophilic Pyridines
作者:Nicolas De Rycke、Guillaume Berionni、François Couty、Herbert Mayr、Regis Goumont、Olivier R. P. David
DOI:10.1021/ol1029589
日期:2011.2.4
3,4,5-Triamino-substituted pyridines are avid for electrophiles but are still willing to give them back. In these compounds three amino groups conjoin their forces into the heterocyclic nitrogen, making it a powerful Lewis base. A short and efficient synthesis is described, and the origin of its unique activity in nucleophilic organocatalysis is rationalized by kinetics and thermodynamic quantifications.
Annelated Pyridines as Highly Nucleophilic and Lewis Basic Catalysts for Acylation Reactions
作者:Raman Tandon、Teresa Unzner、Tobias A. Nigst、Nicolas De Rycke、Peter Mayer、Bernd Wendt、Olivier R. P. David、Hendrik Zipse
DOI:10.1002/chem.201204452
日期:2013.5.10
their nucleophilicity and Lewisbasicity. The Lewisbasicity of these bases as quantified through their theoretically calculated methyl‐cation affinities correlate well with the experimentally measured reaction rates for addition to benzhydryl cations. All newly synthesized pyridines show exceptional catalytic activities in benchmark acylationreactions, which correlate only poorly with Lewis basicity