N-acylazinium salts: a new source of iminium ions for Ugi-type processes.
Parc Científic de Barcelona, University of Barcelona, Josep Samitier 1-5, 08028 Barcelona, Spain.
A multicomponent reaction involving the interaction of azines (quinolines, isoquinolines, and phenanthridine) with activating agents (chloroformates, acid halides, and sulfonyl halides), isocyanides, and water is described. The products of this process, alpha-carbamoylated-1,2-dihydroazines, are the result of the addition of the isocyanide partner to the N-acylazinium salt formed in situ. This represents a new source of iminium ion equivalents for Ugi-type reactions.
PMID: 15132569 [PubMed]