Polynorbornene by Coördination Polymerization¹

Basak T., Trzaskowski B.

Antonova Alexandra S., Zubkov Fedor I.

Catalytic olefin metathesis using Hoveyda-Grubbs type ruthenium complexes is a powerful tool for creating complex molecules possessing a variety of practically useful properties. This method is also applied for obtaining modern polymer materials from low-demand petroleum products. Among all ruthenium complexes containing five- or six-membered chelate rings, the commercially available HG-II catalyst is the most common. In addition, other Hoveyda-Grubbs type complexes, which include a Het→Ru donor–acceptor bond in the chelate ring, often exhibit metathesis activity equal to or superior to that of HG-II. This review considers second-generation N-heterocyclic ruthenium carbene Hoveyda-Grubbs type complexes with donor–acceptor bonds such as O→Ru, S→Ru, Se→Ru, N→Ru, P→Ru and Hal→Ru in the chelate ring. Methods of preparation, analysis of stability and catalytic activity of such complexes are compared, and examples of the application of these organometallic ruthenium derivatives in the synthesis of practically relevant products are provided. The literature from 2010 to 2023 is summarized, making this review useful for a broad audience of chemists working in heterocyclic and organometallic chemistry, as well as practitioners involved in the production of catalysts and polymers.The bibliography includes 174 references.

Park E.J., Jannasch P., Miyatake K., Bae C., Noonan K., Fujimoto C., Holdcroft S., Varcoe J.R., Henkensmeier D., Guiver M.D., Kim Y.S.

This review provides a depth of knowledge on the synthesis, properties and performance of aryl ether-free anion exchange polymer electrolytes for electrochemical and energy devices.

Morvan J., Del Vecchio A., Talcik J., Bouëtard D., Mauduit M.

AbstractAsymmetric Olefin Metathesis (AOM) represents a highly versatile synthetic tool to lead to relevant chiral building blocks with excellent enantiopurity. As the Z‐alkene moiety is ubiquitous in a wide range of natural products, the development of catalysts which are able to control both the Z‐selectivity and the enantioselectivity of metathesis transformations is in high demands. This review aims to provide a comprehensive overview covering all the breakthroughs accomplished in the field of challenging Z‐enantioselective olefin metathesis, which is of interest in the total synthesis of complex molecules.

Bai H., Han L., Wang X., Yan H., Leng H., Chen S., Ma H.

Davas D.S., Bhardwaj S., Sen R., Gopalakrishnan D.K., Vaitla J.

Prieto Kullmer C.N., Kautzky J.A., Krska S.W., Nowak T., Dreher S.D., MacMillan D.W.

Reaction generality is crucial in determining the overall impact and usefulness of synthetic methods. Typical generalization protocols require a priori mechanistic understanding and suffer when applied to complex, less understood systems. We developed an additive mapping approach that rapidly expands the utility of synthetic methods while generating concurrent mechanistic insight. Validation of this approach on the metallaphotoredox decarboxylative arylation resulted in the discovery of a phthalimide ligand additive that overcomes many lingering limitations of this reaction and has important mechanistic implications for nickel-catalyzed cross-couplings.

Nechmad N.B., Lemcoff N.G., Delaude L.

This chapter surveys the various types of ruthenium benzylidene complexes that were described in the literature within the years 1995–2021. The emphasis is placed on their synthesis, characterization, and chemical reactivity rather than their catalytic activity. Some remarkable structure/activity relationships that helped tailoring the coordination sphere of the metal center through ligand design in order to achieve the highest possible activities and selectivities toward various kinds of olefin metathesis reactions are nonetheless highlighted. A brief overview of the few ruthenium benzylidyne complexes that have been reported thus far is also included.

Rohland P., Schröter E., Nolte O., Newkome G.R., Hager M.D., Schubert U.S.

Renewable organic batteries represent a valuable option to store sustainably generated energy and can play a major role in phasing out current carbon-based energy production. Several approaches have emerged over the last 80 years that utilize organic redox materials as active components in batteries. In particular, polymers have gained considerable interest among numerous research groups due to their (1) fast redox chemistry, in comparison to conventional active materials, (2) straight-forward syntheses, and (3) tunable solubility, which represent favored properties for diverse electronic devices. Notably, the beginning of redox-active polymers is linked to the discovery of conductive polymers by Heeger, MacDiarmid and Shirakawa in 1977. Nevertheless, redox-active polymers were studied in 1944 making them a familiar class under the broader polymeric framework, which celebrate its 100th birthday in 2020, based on the pioneering publication by Staudinger in 1920. Since their beginning, redox-active polymers have evolved from an interesting phenomenon into a family of promising, tailor-made, battery materials that also made their way to commercialization. In this regard, this review focusses on the design of interesting polymeric, redox-active materials. Polymerization techniques are discussed regarding novel polymer architectures and utilitarian properties. The polymer architectures are subsequently analyzed within the application scenarios of solid-state batteries, pseudo-capacitors, and redox-flow batteries. Redox moieties are compared and an overview of diverse synthetic aspects as well as battery concepts for the optimal assembly of polymeric battery materials are given.

Osakada K.

This chapter presents fascinating insights into the research that earned its investigators Nobel Prizes in the field of organometallic chemistry: Karl Ziegler and Giulio Natta for olefin polymerization catalysts (1963), Ernst Otto Fischer and Geoffrey Wilkinson for sandwich compounds (1973), Alan J. Heeger, Alan G. MacDiarmid, and Hideki Shirakawa for electrically conductive polymers (2000), William S. Knowles, Ryoji Noyori and K. Barry Sharpless for asymmetric catalysis (2001), Yves Chauvin, Robert H. Grubbs and Richard R. Schrock for olefin metathesis (2005), and Richard F. Heck, Eiichi Negishi and Akira Suzuki for Pd-catalyzed cross-coupling reactions (2010).

Belov D.S., Tejeda G., Bukhryakov K.V.

In this Minireview, alkylidenes and metallacyclobutanes of the first-row metals capable of performing cycloaddition and cycloreversion reactions, the critical steps in olefin metathesis reactions, are discussed. Also, examples of olefin metathesis catalyzed by first-row metal complexes are shown. The high abundance of base metals could potentially provide inexpensive and greener alternatives to existing methods.

Klemmer L., Thömmes A., Zimmer M., Huch V., Morgenstern B., Scheschkewitz D.

The metathesis of carbon–carbon double bonds—the ‘reshuffling’ of their constituting carbene fragments—is a tremendously important preparative tool in industry and academia. Metathesis of heavier alkene homologues is restricted to occasional unproductive examples in phosphorus chemistry and cross-metathesis to mixed heavier alkynes. We now report the thermally induced, transition-metal-free metathesis of purpose-built unsymmetrically substituted digermenes. The A2Ge=GeAB starting materials are thus converted to symmetrically substituted derivatives of the A2Ge=GeA2 and ABGe=GeAB types. The use of tethered auxiliary donors (dimethylaniline groups) in substituents B ensures intramolecular donor–acceptor stabilization of the transient germylene fragments, the intermediacy of which is proven by trapping experiments. Density functional theory calculations shed light on the thermodynamic driving force of the metathesis and validate the crucial role of the tethered donor. With an analogously equipped bridged tetragermadiene precursor (A2Ge=GeB-X-BGe=GeA2), heavier acyclic diene metathesis polymerization occurs, in analogy to the widespread acyclic diene metathesis (ADMET) polymerization in the carbon case, yielding a polydigermene. The metathesis of carbon–carbon double bonds is an important tool in organic synthesis and now a similar reshuffling has been carried out with heavier alkene analogues featuring unsymmetrically substituted Ge=Ge double bonds. This reaction enables the synthesis of symmetric molecular digermenes as well as a polymer based on Ge=Ge repeat units.

Copéret C., Berkson Z.J., Chan K.W., de Jesus Silva J., Gordon C.P., Pucino M., Zhizhko P.A.

Surface organometallic chemistry bridges the gap between homogeneous and heterogeneous olefin metathesis catalysts.

Belov D.S., Mathivathanan L., Beazley M.J., Martin W.B., Bukhryakov K.V.

Belov D.S., Mathivathanan L., Beazley M.J., Martin W.B., Bukhryakov K.V.

Developing well-defined iron-based catalysts for olefin metathesis would be a breakthrough achievement in the field not only to replace existing catalysts by inexpensive metals but also to attain a new reactivity taking advantage of the unique electronic structure of the base metals. Here, we present a two-coordinate homoleptic iron complex, Fe(HMTO)2 [HMTO=O-2,6-(2,4,6-Me3 C6 H2 )2 C6 H3 ], that is capable of performing ring-opening metathesis polymerization of norbornene to produce highly stereoregular polynorbornene (99 % cis, syndiotactic). The use of heteroleptic Fe(HMTO)(RO) [RO=(CH3 )2 CF3 CO, CH3 (CF3 )2 CO, or Ph(CF3 )2 CO] prepared in situ significantly increases the polymerization rate while preserving selectivity. The resulting polymers were characterized by 1 H and 13 C NMR spectroscopy and gel-permeation chromatography.