Scope and mechanistic study of the ruthenium-catalyzed ortho-C-H bond activation and cyclization reactions of arylamines with terminal alkynes. J Am Chem Soc 2005 Dec 07;127(48):17000-6
Date
12/01/2005Pubmed ID
16316246Pubmed Central ID
PMC2585980DOI
10.1021/ja055608sScopus ID
2-s2.0-28844489387 (requires institutional sign-in at Scopus site) 143 CitationsAbstract
The cationic ruthenium hydride complex [(PCy(3))(2)(CO)(CH(3)CN)(2)RuH](+)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 Ru(3)(CO)(12)/HBF(4).OEt(2). The normal isotope effect (k(CH)/k(CD) = 2.5) was observed for the reaction of C(6)H(5)NH(2) and C(6)D(5)NH(2) with propyne. A highly negative Hammett value (rho = -4.4) was obtained from the correlation of the relative rates from a series of meta-substituted anilines, m-XC(6)H(4)NH(2), with sigma(p) in the presence of Ru(3)(CO)(12)/HBF(4).OEt(2) (3 mol % Ru, 1:3 molar ratio). The deuterium labeling studies from the reactions of both indoline and acyclic arylamines with DCCPh 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 DCCPh and HCCC(6)H(4)-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.
Author List
Yi CS, Yun SYAuthor
Chae Yi PhD Professor, Inorganic and Organometallic Chemistry, Homogeneous Catalysis in the Chemistry department at Marquette UniversityMESH terms used to index this publication - Major topics in bold
AlkynesAniline Compounds
Catalysis
Cyclization
Kinetics
Organometallic Compounds
Quinolines
Quinoxalines
Ruthenium