RESUMO
The development of an efficient method for the synthesis of polysubstituted isoindolinones from 1,3-dicarbonyl Ugi-4CR adducts, employing an aromatic radical cyclization process promoted by tetrabutylammonium persulfate and 2,2,6,6-tetramethyl-1-piperidine 1-oxyl (TEMPO), is described. The protocol allowed the construction of a library of isoindolinones bearing a congested carbon in good to excellent yields under mild conditions and in short reaction times.
RESUMO
A practical one-pot synthesis of nicotine analogs from Ugi 4-CR/propargyl adducts is reported. This methodology allows the rapid construction of the pyrrolidine moiety present in nicotine through an intramolecular base-promoted 5-endo cycloisomerization process, followed by a reduction of the resulting mixture of 2- and 3-pyrrolines to afford nicotine analogs in good overall yields.
Assuntos
Técnicas de Química Combinatória/métodos , Nicotina/análogos & derivados , Nicotina/síntese química , Catálise , Ciclização , Éteres de Hidroxibenzoatos/química , Estrutura Molecular , Nicotina/química , Oxirredução , Paládio/química , Pargilina/análogos & derivados , Pargilina/química , Propilaminas/química , Piridinas/química , EstereoisomerismoRESUMO
A practical two-step synthesis of 2,3-dihydropyrroles from Ugi 4-CR/propargyl adducts is presented. The protocol includes a base-mediated formation of an allenamide functional group and an in situ metal-free formal 5-endo cycloisomerization that occurs in a highly regioselective manner at the allenamide C-γ.