Unexpected regio- and chemoselectivity of cationic gold-catalyzed cycloisomerizations of propargylureas: access to tetrasubstituted 3,4-dihydropyrimidin-2(1H)-ones.
Cationic gold-catalyzed cycloisomerizations of propargylureas, derived in situ from secondary propargylamines and aryl or alkyl isocyanates, have been studied. The reaction outcome was found to be different from what was previously observed for the tosyl isocyanate-derived ureas in terms of both regio- and chemoselectivity. As a result, the current protocol offers efficient access to the 3,4-dihydropyrimidin-2(1H)-one core through the 6-endo-dig N-cyclization.
Laboratory for Organic & Microwave-Assisted Chemistry (LOMAC), Department of Chemistry, University of Leuven (KU Leuven), Celestijnenlaan 200F, B-3001, Leuven, Belgium. vapeshkov@gmail.com erik.vandereycken@chem.kuleuven.be.
Olga P
OP
Pereshivko
Vsevolod A
VA
Peshkov
Anatoly A
AA
Peshkov
Jeroen
J
Jacobs
Luc
L
Van Meervelt
Erik V
EV
Van der Eycken
D002384:Catalysis; D002412:Cations; D018360:Crystallography, X-Ray; D003500:Cyclization; D006046:Gold / Q000737:chemistry*; D007536:Isomerism; D011744:Pyrimidinones / Q000737:chemistry*; D014508:Urea / Q000737:chemistry*
D002412:Cations; D011744:Pyrimidinones; D006046:Gold; D014508:Urea