146746-36-3Relevant articles and documents
General Chemoselective Suzuki-Miyaura Coupling of Polyhalogenated Aryl Triflates Enabled by an Alkyl-Heteroaryl-Based Phosphine Ligand
So, Chau Ming,Yuen, On Ying,Ng, Shan Shan,Chen, Zicong
, p. 7820 - 7827 (2021/07/01)
This study describes a general chemoselective Suzuki-Miyaura coupling of polyhalogenated aryl triflates with the reactivity order of C-Cl > C-OTf using a Pd/L33 catalyst. The methine hydrogen and the steric hindrance offered by the alkyl bottom ring of L33 were found to be key factors in reactivity and chemoselectivity. With the Pd/ L33 catalyst, a wide range of polyhalogenated (hetero)aryl triflates, which were independent of the substrates and of the relative positioning of the competing reaction sites, coupled well with (hetero)aryl, alkenyl, and alkylboronic acids to obtain the corresponding products with good chemoselectivity and yields. The chemoselective reaction could easily be scaled up to the gram scale, and the use of parts per million levels of Pd catalyst (as low as 10 ppm Pd) was achieved.
An Intramolecular Arene-Triflate Coupling Reaction for the Regiospecific Synthesis of Substituted Benzofluoranthenes
Rice, Joseph E.,Cai, Zhen-Wei
, p. 1415 - 1424 (2007/10/02)
An intramolecular triflate-arene coupling reaction mediated by bis(triphenylphosphine)palladium(II) chloride has been developed for the synthesis of each of the isomeric benzofluoranthenes.This reaction, which results in formation of a new five-membered ring, proceeds in highest yields when performed using 0.1 equiv of the palladium catalyst, 3 eqiv of lithium chloride, and 1.2 eqiv of 1,8-diazabicycloundec-7-ene in N,N-dimethylformamide at 140 deg C.The biaryl precursors needed for the coupling reaction can be prepared by nickel(II) chloride catalyzed coupling of an aryl bromide with an magnesium bromide (prepared by ortho-lithiation of an aryl methoxymethyl ether followed by transmetalation with magnesium bromide).Using this procedure benzofluoranthene, benzofluoranthene, benzofluoranthene, and benzofluoranthene were prepared in yields of 84percent, 85percent, 93percent and 64percent, respectively.The reaction to prepare benzofluoranthene was regiospecific and afforded none of the six-membered ring product, perylene.This method was extended to the preparation of benzofluoranthene (BbF) derivatives with fluoro or methoxy groups on the benzo ring.The cyclization of compounds posessing a methoxy group on the same ring as the triflate required the addition of 0.4 equiv of triphenylphosphine to the reaction mixture.Strategies are reported for the regiospecific preparation of 4-, 5-, 6-, and 7-substituted benzofluoranthenes.Evidence is presented wich suggests the intermediacy of radicals in the oxidative-addition of aryl triflates to the palladium catalyst.
