Highly efficient palladium-catalyzed cross-coupling of diarylborinic acids with arenediazoniums for practical diaryl synthesis
作者:Fengze Wang、Chen Wang、Guoping Sun、Gang Zou
DOI:10.1016/j.tetlet.2019.151491
日期:2020.2
A highly efficient cross-coupling of cost-effective diarylborinic acids with both isolatable and latent arenediazoniums, i.e. tetrafluoroborates and aryltriazenes, respectively, has been developed with a practical palladium catalyst system under base-free conditions in open flask at room temperature. A variety of electronically and sterically various biaryls, in particular, those bearing a coordinative
magnetic resonance (NMR) studies have benefited tremendously from the steady increase in the strength of magnetic fields. Spectacular improvements in both sensitivity and resolution have enabled the investigation of molecular systems of rising complexity. At very high fields, this progress may be jeopardized by line broadening, which is due to chemicalexchange or relaxation by chemical shift anisotropy
A new approach to benzylamines using triazene compounds has been developed that is facilitated by the lithiation of aryltriazenes followed by treatment with an electrophile. The regioselectivity of the reaction can be controlled by means of the substituents in the aryl group. The reaction contains the following steps: intramolecular carbon-carbon bond formation involving lithiation of an alkyl group on a 3-nitrogen atom; a 1,2-proton shift; and the subsequent release of nitrogen gas. Through the use of a deuterated triazene, we were able to determine that the reaction proceeds through a 1,2-proton shift. (c) 2006 Elsevier Ltd. All rights reserved.