Ruthenium-catalyzed intermolecular coupling reactions of arylamines with ethylene and 1,3-dienes: mechanistic insight on hydroamination vs ortho-C-H bond activation.
[reaction: see text]. The cationic ruthenium complex [(PCy3)2(CO)(Cl)Ru=CHCH=C(CH3)2]+BF4- was found to be an effective catalyst for the coupling reaction of aniline and ethylene to form a approximately 1:1 ratio of N-ethylaniline and 2-methylquinoline products. The analogous reaction with 1,3-dienes resulted in the preferential formation of Markovnikov addition products. The normal isotope effect of k(NH)/k(ND) = 2.2 (aniline and aniline-d7 at 80 degrees C) and the Hammett rho = -0.43 (correlation of para-substituted p-X-C6H4NH2) suggest an N-H bond activation rate-limiting step for the catalytic reaction.
Yi
Chae S
CS
Department of Chemistry, Marquette University, Milwaukee, Wisconsin 53201-1881, USA. chae.yi@marquette.edu
Yun
Sang Young
SY
D000466:Alkadienes / Q000737:chemistry*; D000588:Amines / Q000737:chemistry*; D000814:Aniline Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D002384:Catalysis; D005030:Ethylenes / Q000737:chemistry*; D007554:Isotopes / Q000493:pharmacokinetics; D011804:Quinolines / Q000138:chemical synthesis*; D012428:Ruthenium / Q000737:chemistry*
D000466:Alkadienes; D000588:Amines; D000814:Aniline Compounds; D005030:Ethylenes; D007554:Isotopes; D011804:Quinolines; D012428:Ruthenium