ChemInform Abstract: Palladium(II)‐Catalyzed Intramolecular Aminocarbonylation of endo‐ Carbamates under Wacker‐Type Conditions.

Abstract

1997 ring closure reactions ring closure reactions O 0130 -054Palladium(II)-Catalyzed Intramolecular Aminocarbonylation of endo-Carbamates under Wacker-Type Conditions.-It is shown that endo-carbamates such as (I), (VI), and (IX) undergo efficient aminocarbonylation in the presence of trimethyl orthoacetate yielding oxazolidinone or oxazinone derivatives. However, aminocarbonylation of other nucleophiles (exocarbamates, exo-and endo-ureas, and exo-tosylamides) is unsuccessful under these conditions. Thus, the chemoselective aminocarbonylation of carbamates of type (XI) can be achieved. In the presence of trimethyl orthoacetate aminocarbonylation takes place at the endo-carbamate moiety yielding oxazolidinones like (XII) and (XIII), whereas in the absence of the orthoacetate pyrroles such as (XIV) and (XV) are formed by aminocarbonylation at the exo-carbamate, exo-urea, as well as exo-tosylamide moieties. -(HARAYAMA, H.; ABE, A.; SAKADO, T.; KIMURA, M.; FUGAMI, K.; TANAKA, S.; TAMARU, Y.; J.