The stereoselective palladium-catalysed synthesis of the heterocycles 13-15 with a (Z)-exocyclic allylsilane moiety is described. Alkylation of the secondary amides 5a, 5b, 9a, and 9b and the phenol 11 containing an iodoaryl moiety with the propargyl iodide 6 leads to the propargylsilanes 7a, 7b, 10a, lob, and 12, which are allowed to react with a catalyst system of Pd(OAc)z/PPh3/NPr,Br and sodium formate as a hydride source. The ( Z ) configuration of the cyclisation products is confirmed by NOESY spectra and a single-crystal Xray structure of 13b.
Tertiäre sp3‐Kohlenstoffzentren selektiv aufzubauen gelingt mit Allylsilanen 1 als Alkenkomponente in der Titelreaktion, so daß nicht wie üblich Doppelbindungsisomere entstehen. Mit einem chiralen Katalysatorsystem ist die Reaktion enantioselektiv durchführbar. Mit [Pd2(dba)3]/PPh3/Ag2O entstehen vorwiegend die Hetero‐ und Carbocyclen 2, mit Pd(OAc)2/PPh3/NPr4Br/KOAc 3.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.