A tethering directing group strategy for ruthenium-catalyzed intramolecular alkene hydroarylation
作者:Praveen Kilaru、Sunil P. Acharya、Pinjing Zhao
DOI:10.1039/c7cc08704g
日期:——
N-heterocycle synthesis that utilizes an alkene-tethered amide moiety as a directing group for aromatic C–H activation. This tethering directing group strategy is demonstrated in a ruthenium-catalyzed intramolecular alkene hydroarylation with N-aryl acrylamides to form oxindole products.
A variety of oxazole derivatives that possess an alpha,beta-unsaturated substituent at the 2-position were conveniently synthesized in good yields via a Hantzsch-type reaction between dehydroamino acid amides and P-bromopyruvate derivatives. Furthermore, oxazoles with substituents at the 2- and 5-positions were also obtained in good yields using the corresponding beta-substituted beta-bromopyruvate derivatives. A revised reaction mechanism to explain the enhanced reactivity of dehydroamino acid amides for the Hantzsch-oxazole-type reaction is presented.
Naster; Gavriloff, Bulletin des Societes Chimiques Belges, 1933, vol. 42, p. 519