PALLADIUM(0)-CATALYZED ALLYLATION OF URACILS AND 2-THIOURACILS DRASTIC EFFECT OF AN AQUEOUS REACTION MEDIUM ON THE REGIOSELECTIVITY

Authors
SIGISMONDI S SINOU D PEREZ M MORENOMANAS M PLEIXATS R VILLARROYA M
Citation
S. Sigismondi et al., PALLADIUM(0)-CATALYZED ALLYLATION OF URACILS AND 2-THIOURACILS DRASTIC EFFECT OF AN AQUEOUS REACTION MEDIUM ON THE REGIOSELECTIVITY, Tetrahedron letters, 35(38), 1994, pp. 7085-7088
Citations number
35
Categorie Soggetti
Chemistry Inorganic & Nuclear
Journal title
Tetrahedron letters → ACNP
ISSN journal
00404039
Volume
35
Issue
38
Year of publication
1994
Pages
7085 - 7088
Database
ISI
SICI code
0040-4039(1994)35:38<7085:PAOUA2>2.0.ZU;2-0
Abstract
Palladium(0)-catalyzed allylation of uracils in DMSO takes place at N- 1 and at N-3. In sharp contrast, regiospecific allylation at N-1 is ac hieved in an organic-aqueous medium in the presence of palladium(II) a cetate and the water-soluble sulfonated triphenylphosphine P(C6H4-m-SO 3Na)(3), (tppts). Similar reactions with 2-thiouracils are also, drast ically dependent on the solvent, taking place at N-1 and N-3 (in dioxa ne) or at sulfur (organic-aqcleous medium). Probably reactions in the organic-aqueous medium are kinetically controlled whereas allylations in DMSO or refluxing dioxane are thermodynamically controlled.