pubmed-article:20939590 | pubmed:abstractText | The tandem Heck-lactonization reaction between enoates Z-1a,b, E-1a, E-2a-d, Z-2e, 2f, and o-iodophenols (4a-f) was studied in the presence of substoichiometric amounts of Pd(OAc)(2) or PdCl(2), under experimental conditions favoring the cationic mechanism (conditions A, B, and C), leading to coumarins 5a-f and 6a-e. Moderate to excellent yields were obtained under aqueous conditions (conditions A and B). Using electrospray ionization for transferring ions directly from solution to the gas phase, and mass spectrometry for structural assignments, key cationic palladium intermediates have been successfully intercepted and structurally characterized for the first time for this type of reaction. | lld:pubmed |
pubmed-article:20939590 | pubmed:affiliation | Laborato?rio de Qui?mica Bioorga?nica (LQB), Nu?cleo de Pesquisas de Produtos Naturais, Centro de Cie?ncias da Sau?de, Bl H, Ilha da Cidade Universita?ria, Universidade Federal do Rio de Janeiro, Rio de Janeiro, 21941-590, Brazil. | lld:pubmed |