Cobalt-catalyzed cyclization of benzamides with alkynes: a facile route to isoquinolones with hydrogen evolution
作者:Ramasamy Manoharan、Masilamani Jeganmohan
DOI:10.1039/c8ob01924j
日期:——
benzamides with alkynes assisted by an 8-aminoquinoline ligand in the presence of Co(OAc)2·4H2O and pivalicacid under an air atmosphere provided isoquinolone derivatives in good to excellent yields. In this reaction, the active Co(III) species is regenerated by the reaction of Co(I) species with pivalicacid under an air atmosphere with hydrogen evolution. The proposed mechanism was supported by competition
A rhodium-catalyzed decarbonylation/alkyne insertion cascade of phthalimides has been established. The reaction can be carried out in an operationally simple manner and provides expedient access to a series of isoquinolones in moderate to good yields. This reaction proceeded through a sequential decarbonylation/alkyne insertion/intramolecular annulation procedure and featured good functional group
Ruthenium-Catalyzed Synthesis of Isoquinolones with 8-Aminoquinoline as a Bidentate Directing Group in C–H Functionalization
作者:Srinivasarao Allu、K. C. Kumara Swamy
DOI:10.1021/jo500424p
日期:2014.5.2
Ruthenium-catalyzed oxidative annulation of N-quinolin-8-yl-benzamides with alkynes in open air has been achieved using 8-aminoquinolinyl moiety as a bidentate directing group in the presence of Cu(OAc)(2)center dot H2O as an oxidant. This reaction offers a broad substrate scope, and both symmetrical and unsymmetrical alkynes can be applied. High regioselectivity was achieved in the case of unsymmetrical (aryl)alkynes. Reaction with heteroaryl amides was also successful in this catalytic process. A ruthenium-N-quinolin-8-yl-benzamide complex was isolated in the absence of alkyne; in the absence of both N-quinolin-8-yl-benzamide and alkyne, in contrast to literature, only the monoacetate complex RuCl(OAc)(p-cymene), but not the bis-acetate complex Ru(OAc)2(p-cymene), was isolated. These data suggest that this reaction may proceed via N,N-bidentate chelate complex. Key products were characterized by X-ray crystallography.