16821-78-6Relevant articles and documents
Palladium-Catalyzed Reductive Cross-Coupling Reaction of Aryl Chromium(0) Fischer Carbene Complexes with Aryl Iodides
Wang, Kang,Lu, Yu,Hu, Fangdong,Yang, Jinghui,Zhang, Yan,Wang, Zhi-Xiang,Wang, Jianbo
, p. 1 - 10 (2018/01/17)
The first palladium-catalyzed reductive cross-couplings of aryl chromium(0) carbene complexes with aryl iodides have been realized. This coupling reaction shows excellent functional group tolerance and high efficiency. Mechanistically, aryl chromium(0) carbene complexes undergo transmetalation with arylpalladium species to generate palladium(II) carbene intermediates, which is followed by migratory insertion. The catalytic cycle is then completed by hydrogen transfer and reductive elimination. Consistent with the mechanistic hypothesis, density functional theory (DFT) calculations support the involvement of a palladium carbene intermediate, and carbene migratory insertion is a facile step with an energy barrier of 5.1 kcal/mol. The carbene transfer step and the hydrogen transfer step are confirmed as the rate-limiting steps in the catalytic cycle.
Dehalogenation of 1-Halogenothienyl-di- and -tetra-hydroisoquinolines by Sodium Methoxide in Dimethyl Sulphoxide
Barker, John M.,Huddleston, Patrick R.,Clephane, Janette,Wood, Michael L.,Holmes, David
, p. 275 - 282 (2007/10/02)
On treatment with sodium methoxide-dimethyl sulphoxide (NaOMe-DMSO) 1-(5-halogeno-2-thienyl)-6,7-dimethoxy-2-methyl-1,2,3,4-tetrahydroisoquinolines suffer loss of halogen and are converted into the related 1-hydroxytetrahydroisoquinolines.The reaction fails with comparable 1-bromophenyl- and 1-(halogeno-3-thienyl)tetrahydroisoquinolines.A similar transformation takes place with (5-halogeno-2-thienyl)phenylmethoxymethanes, leading to the dimethyl acetal of the 5-dehalogenated-2-thienyl phenyl ketone. α-Halogenated-2 and 3-thienyl-3,4-dihydroisoquinolines undergo dehalogenation-aromatisation with NaOMe-DMSO.Mechanisms for these conversions are proposed.
