YLURES SANS SEL, EVOLUTION EN PHOSPHORANES ET EQUILIBRE YLURE PHOSPHORANE I. SYNTHESE ET STRUCTURE

Article abstract of DOI:10.1016/S0040-4020(01)96522-6

Synthesis of new salt-free ylids 9, 12 to 16, 19, 20, 22, 27 and 29 and phosphoranes 10, 17, 18, 21, 23, 30 to 33 by addition of a trivalent phosphorus compound (phosphites and amino-phosphines) 1 to 7 with dimethyl acetylenedicarboxylate in presence of a protic trapping reagent are described.The results are consistent with trapping of carbanionic species.In relation with the cyclic or acyclic structure of the trivalent phosphorus compound and the protic trapping reagent ie: methanol, phenol, carboxylic acid, etc.., several pathways are involved.Clearly, three phenomena are shown: one can obtain an ylid via a phosphorane or conversely a phosphorane via an ylid or an equilibrium phosphorane <*> ylid.Results are dealing with thermodynamic or kinetically controlled reactions.