Pyrrolidine-2,3,4-tricarboxylic anhydrides: I. Organocatalytic synthesis and fusion of pyrrole ring by the action of p-fluorobenzylamine
作者:K. V. Kudryavtsev、E. V. Trofimova、A. O. Borisova
DOI:10.1134/s1070428011040142
日期:2011.4
N-Boc-glycine effectively catalyzes 1,3-dipolar cycloaddition of maleic anhydride to N-benzylidene alpha-amino acid esters, which leads to the formation of pyrrolidine-2,3,4-tricarboxylic anhydrides. The subsequent opening of the anhydride fragment in the adducts by the action of p-fluorobenzylamine is regioselective, and it involves recyclization to produce polysubstituted octahydropyrrolo[3,4-b]pyrroles. The newly synthesized fused pyrrolidines inhibit enzymatic activity of thrombin (factor IIA) in vitro.
XY–ZH Systems as potential 1,3-dipoles. Part 8. Pyrrolidines and Δ<sup>5</sup>-pyrrolines (3,7-diazabicyclo[3.3.0]octenes) from the reaction of imines of α-amino acids and their esters with cyclic dipolarophiles. Mechanism of racemisation of α-amino acids and their esters in the presence of aldehydes
Imines of α-aminoacidesters with aromatic, heterocyclic, and aliphatic aldehydes generate azomethine ylides stereospecifically by a prototropic shift on heating in toluene. The azomethine ylides undergo cycloaddition to N-phenylmaleimide, maleic anhydride, and p-naphthoquinone via an endo-transition state to give racemic, single diastereoisomeric, cycloadducts. α-Aminoacids undergo analogous cycloadditions