51678-98-9Relevant articles and documents
Scope and mechanistic study of the ruthenium-catalyzed ortho-C-H bond activation and cyclization reactions of arylamines with terminal alkynes
Yi, Chae S.,Yun, Sang Young
, p. 17000 - 17006 (2005)
The cationic ruthenium hydride complex [(PCy3) 2(CO)(CH3CN)2RuH]+BF 4- was found to be a highly effective catalyst for the C-H bond activation reaction of arylamines and terminal alkynes. The regioselective catalytic synthesis of substituted quinoline and quinoxaline derivatives was achieved from the ortho-C-H bond activation reaction of arylamines and terminal alkynes by using the catalyst Ru3-(CO)12/HBF 4·OEt2. The normal isotope effect (k CH/kCD = 2.5) was observed for the reaction of C 6H5NH2 and C6D5NH 2 with propyne. A highly negative Hammett value (ρ = -4.4) was obtained from the correlation of the relative rates from a series of meta-substituted anilines, m-XC6H4NH2, with σp in the presence of Ru3(CO)12/ HBF4·OEt2 (3 mol % Ru, 1:3 molar ratio). The deuterium labeling studies from the reactions of both indoline and acyclic arylamines with DC≡CPh showed that the alkyne C-H bond activation step is reversible. The crossover experiment from the reaction of 1-(2-amino-1-phenyl)pyrrole with DC≡CPh and HC≡CC6H4-p-OMe led to preferential deuterium incorporation to the phenyl-substituted quinoline product. A mechanism involving rate-determining ortho-C-H bond activation and intramolecular C-N bond formation steps via an unsaturated cationic ruthenium acetylide complex has been proposed.
