<正>A novel approach to the synthesis of 2,2′,3,3′-biphenyltetracarboxylic dianhydride is described.The target compound was prepared by a nickel-catalyzed cou
<正>Pyridinium bromochromate has been found to be a highly efficient and selective reagent for theα-monobromination of 1,3-diketones andβ-keto-esters in the a