Hydride-Donor Abilities of 1,4-Dihydropyridines: A Comparison with π Nucleophiles and Borohydride Anions
作者:Dorothea Richter、Herbert Mayr
DOI:10.1002/anie.200804263
日期:2009.3.2
How are dihydropyridines like indoles? Both groups of compounds have similar nucleophilicity parameters N and are therefore suitable substrates for iminium‐catalyzed reactions of α,β‐unsaturated aldehydes. The N parameters of 1,4‐dihydropyridines were derived from the rates of hydride transfer reactions to benzhydrylium ions (see scheme).
Electrophilicity Parameters of 5-Benzylidene-2,2-dimethyl[1,3]dioxane-4,6-diones (Benzylidene Meldrum's Acids)
作者:Oliver Kaumanns、Herbert Mayr
DOI:10.1021/jo702590s
日期:2008.4.1
electrophilicity parameters for various β,β-acceptor substituted styrenes and thus to predict a large number of absoluterate constants for a manifold of Michael additions. The reactions of primary and secondary amines are approximately 2 orders of magnitude faster than predicted by the correlation (1), supporting transition states which are stabilized by hydrogen bridges from NH to the carbonyl groups of