A Brønstedbase-catalyzedtandem [2+4] annulation/tautomerization/aromatization reaction of α-alkylidene succinimides with 5-alkenyl thiazolones has been developed for synthesis of functionalized thiazolo pyrones under mild conditions. The prepared thiazolo pyrones show fluorescent properties.
We report a highly chemo- and diastereoselective [3 + 2] cyclization of vinylethylene carbonates and 5-alkenyl thiazolones through palladium catalysis. The previously inert aza-thioester moiety on the thiazolone substrates is reacted selectively with the zwitterionic pi-allylpalladium species. A variety of amide monothioacetals (AMTA) with two quaternary stereocenters are facilely synthesized. An additional spirocyclic quaternary stereocenter could be further installed by Rh-catalyzed metal-carbene insertion into the C-S bond on the AMTA moiety in a highly stereoselective manner.
ZAYED, EZZAT, M.;ELBANNANY, AFAFA, A.;GHOZLAN, SAID, A. S., PHARMAZIE, 1985, 40, N 3, 194-196
作者:ZAYED, EZZAT, M.、ELBANNANY, AFAFA, A.、GHOZLAN, SAID, A. S.