28249-66-3Relevant academic research and scientific papers
Synthetic, spectroscopic, and computational investigations of readily accessible 2-phenyl-3-alkylbenzoxazaboroles
Abeysinghe, Janaka P.,George, Sobiya,Gross, Dustin E.,Lynch, Vincent M.,Rathnayaka, Chathurika
, (2022/01/26)
We report several new benzoxazaboroles using 2-aminophenol or 2-(alkylamino)phenols and phenylboronic acid derivatives. Bis(benzoxazaborole)s were also synthesized using aminophenols and diboronic acids. Characterization of benzoxazaboroles and bis(benzox
Chan-Evans-Lam Couplings with Copper Iminoarylsulfonate Complexes: Scope and Mechanism
Hardouin Duparc, Valérie,Bano, Guillaume L.,Schaper, Frank
, p. 7308 - 7325 (2018/07/05)
Copper(II) pyridyliminoarylsulfonate complexes with chloride or triflate counteranions were employed in Chan-Evans-Lam (CEL) couplings of N-nucleophiles and arylboronic acids. The complexes avoided typical side reactions in CEL couplings, and an excess of boronic acid was not required. Water was tolerated, and addition of neither base nor other additives was necessary. Primary amines, acyclic and cyclic secondary amines, anilines, aminophenol, imidazole, pyrazole, and phenyltetrazole can be quantitatively arylated at either 25 or 50 °C with 2.5 mol % of the catalyst. Reaction kinetics were investigated in detail. Kinetic and spectroscopic studies provide evidence for the formation of unproductive copper-substrate complexes. Formation of an aniline-phenylboronic acid adduct was responsible for the zero-order dependence of reaction rates on phenylboronic acid concentration. Kinetic evidence indicates that the order of reaction steps is transmetalation, nucleophile coordination, and oxidation. Couplings performed poorly with electron-deficient arylboronic acids, due to a slower Cu(II)/Cu(III) oxidation in the catalytic cycle. Photoredox catalysis partially resolved this problem, but addition of copper acetate as an external oxidant proved to be more efficient.
Sulfonato-imino copper(II) complexes: Fast and general Chan-Evans-Lam coupling of amines and anilines
Hardouin Duparc,Schaper
supporting information, p. 12766 - 12770 (2017/10/11)
Sulfonato-imine copper complexes with either chloride or triflate counteranions were prepared in a one-step reaction followed by anion-exchange. They are highly active in Chan-Evans-Lam couplings under mild conditions with a variety of amines or anilines, in particular with sterically hindered substrates. No optimization of reaction conditions other than time and/or temperature is required.
