Macrocyclic lactones, ketones, and ethers can be obtained in the High-Concentration Ring-Closing Metathesis (HC-RCM) reaction in high yield and selectivity at concentrations 40 to 380 times higher than those typically used by organic chemists for similar macrocyclizations. The new method consists of using tailored ruthenium catalysts together with applying vacuum to distill off the macrocyclic product as it is formed by the metathetical backbiting of oligomers. Unlike classical RCM, no large quantities of organic solvents are used, but rather inexpensive nonvolatile diluents, such as natural or synthetic paraffin oils. Moreover, use of a protecting atmosphere or a glovebox is not needed, as the new catalysts are perfectly moisture and air stable. In addition, some other cyclic compounds previously reported as unobtainable by RCM in neat conditions, or in high dilutions even, can be formed with the help of the HC-RCM method.

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A series of novel complexes [Ni(η(5)-C5H4R)(L)(NHC)](+)A(-)2a-2j and [Ni(η(5)-C5H5)(A)(NHC)] 3a-3c has been obtained by anion metathesis from the corresponding chlorides 1a-1d, depending on the anion binding properties and reaction conditions. Solid-state structures of two cationic complexes (2c, 2j) and two complexes with a coordinated anion (3a, 3c) have been determined by X-ray diffraction revealing a trigonal planar geometry in all cases. Unexpectedly, 3c displayed unprecedented for this type of compounds temperature-dependent NMR spectra that were interpreted in terms of spin equilibrium. The cationic complexes 2 were less efficient in styrene polymerization than the parent chlorides 1. However, the activity of 2 and 3 in Suzuki cross-coupling did not depend considerably on the counterion.

Singlecrystal X-ray structures were determined for complexes 1d [Ni(η 5 -C 5 H 5 )(Cl)(Bn 2 -bimy)] (Bn 2 -bimy = 1,3-dibenzylbenz-

The number of people affected by diabetes mellitus increases globally year on year. Elevated blood glucose levels may result from a lack of insulin to manage these levels and can, over a prolonged period, lead to serious repercussions. Diabetes mellitus patients must monitor and control their blood‐glucose levels with invasive testing and often alongside administration of intravenous doses of insulin, which can often lead to suboptimal compliance. To mitigate these issues, “closed‐loop” insulin delivery systems are deemed to be among superior options for rapid relief from the demanding and troublesome necessity of self‐directed care. The reversible dynamic covalent chemistry of boronic acid derivatives and their competitive affinity to 1,2‐ and 1,3‐diols (such as those present in saccharides) allows for the design and preparation of responsive self‐regulated insulin delivery materials which respond to elevated and changing glucose levels. A range of meritorious and noteworthy contributions in the domain of boron‐mediated insulin delivery materials is surveyed, and providing a multidisciplinary context in the realisation of the ambitious goal of ultimately addressing the desire to furnish glucose‐responsive insulin delivery materials through innovative synthesis and rigorous testing is targetted.