Preparation and applications of metal complexes supported by fluorene- and anthrone-functionalized (bis)mesoionic 1,2,3-triazol-5-ylidenes

Abstract

We report the facile preparation of a novel series of fluorene- and anthrone-derived (bis)triazolium salts and their use as precurors for the synthesis of their corresponding (bis)triazol-5-ylidene silver(I) and palladium(II) complexes. All new compounds have been characterized by different spectroscopical techniques, elemental analyses, and in the case of triazolium salts 2a and 2b and the palladium complex 4b, by single crystal X-ray diffraction. The fluorene-derived (bis)triazolylidene silver complex 3b was applied in the catalytic synthesis of substituted propargyl amines via the KA² (ketone–alkyne–amine) coupling under mild conditions. Furthermore, the palladium complex (4b) performed well in the Suzuki–Miyaura coupling of ortho-substituted aryl chlorides and boronic acids producing challenging ortho-subsituted biaryls under low catalyst loadings and low reaction temperatures.