Heterocycle-fused cyclopentadienyl metal complexes: Heterocene synthesis, structure and catalytic applications

Bimetallic complexes that merge metallocene and pincer-metal building blocks: synthesis, stereochemistry and catalytic reactivity

“…[16][17][18][19][20][21][22][23][24] Notably, in polymerization catalysis rather than a genuine metallocene, so-called half-sandwich metallocenes, i.e., metallocenes in which one of the two Cp rings is replaced by other neutral/anionic ligands, have found extensive application. [25][26][27][28][29][30] The exploration of complexes with a pincer-metal platform is a more recent development although the isolation of the first pincer complexes by Shaw et al already dates back to the mid 1970′s. 31 A pincer-metal complex is defined by the cooperative interaction of the three donor sites of a monoanionic planar, D,C,D′-terdentate pincer ligand with the metal center, of which, generally, the binding with the central (mostly carboanionic) donor site C is the dominating one.…”

“…[32][33][34] For example, pincer-metal complexes have been used as excellent catalysts for a plethora of transformations in organic synthesis such as hydrogenations, dehydrogenation, cross-coupling, borylations, etc. [35][36][37][38][39][40][41][42][43][44][45][46][47][48] In view of the orthogonal properties of the metallocene and the pincer-metal platform, combined with the fact that metallocenes are well-accessible to functionalization 6,7,30,49 the question arises; "Could a merger of metallocene and pincermetal aspects lead to discovery of novel materials with dual properties"? This Perspectives explores what already has been reported and discusses the peculiar effects that have been discovered for these bimetallic species.…”

Preparation of High-Purity Ammonium Tetrakis(pentafluorophenyl)borate for the Activation of Olefin Polymerization Catalysts

“…Since the serendipitous discovery of methylaluminoxane (MAO) by Kaminsky, much effort has been devoted to the synthesis of organometallic complexes to find efficient single-site homogeneous olefin polymerization catalysts, some of which are currently used in the bulk polyolefin industry [ 1 ]. The initial metallocene complexes (i.e., L -MCl 2 -type complexes, where L and M are cyclopentadienyl-type ligands and group-four metals, respectively) have been followed by the development of half-metallocene complexes, in which one of the two cyclopentadienyl-type ligands in metallocenes is replaced with an amido or aryloxo ligand, and further by post-metallocene complexes that do not contain any cyclopentadienyl-type ligands [ 2 , 3 ]. The central group-four transition metals have also been expanded to Ni, Pd, Fe, Co, Cr, and V, especially in post-metallocene complexes [ 4 , 5 , 6 , 7 ].…”

Synthesis, Characterization, and Preliminary In Vitro Cytotoxic Evaluation of a Series of 2-Substituted Benzo [d] [1,3] Azoles

“…Heterocyclic structures are widely distributed in nature and occur as key fragments of biomolecules, e.g., amino acids, nucleic acids, vitamins, natural products, enzymes, biological targets, etc. Besides, they constitute numerous synthetic compounds with relevant applications in different branches of chemistry and technology [ 1 , 2 , 3 , 4 ].…”