Aryl boronic acids and esters are important building blocks in API synthesis. The palladium-catalyzed Suzuki-Miyaura borylation is the most common method for their preparation. This paper describes an improvement of the current reaction conditions. By using lipophilic bases such as potassium 2-ethyl hexanoate, the borylation reaction could be achieved at 35 °C in less than 2 h with very low palladium loading (0.5 mol %). A preliminary mechanistic study shows a hitherto unrecognized inhibitory effect by the carboxylate anion on the catalytic cycle, whereas 2-ethyl hexanoate minimizes this inhibitory effect. This improved methodology enables borylation of a wide range of substrates under mild conditions.

The thermodynamics of halogen bonding of a series of isostructural Group 10 metal pincer fluoride complexes of the type [(3,5‐R2‐tBuPOCOPtBu)MF] (3,5‐R2‐tBuPOCOPtBu=κ3‐C6HR2‐2,6‐(OPtBu2)2 with R=H, tBu, COOMe; M=Ni, Pd, Pt) and iodopentafluorobenzene was investigated. Based on NMR experiments at different temperatures, all complexes 1‐tBu (R=tBu, M=Ni), 2‐H (R=H, M=Pd), 2‐tBu (R=tBu, M=Pd), 2‐COOMe (R=COOMe, M=Pd) and 3‐tBu (R=tBu, M=Pt) form strong halogen bonds with Pd complexes showing significantly stronger binding to iodopentafluorobenzene. Structural and computational analysis of a model adduct of complex 2‐tBu with 1,4‐diiodotetrafluorobenzene as well as of structures of iodopentafluorobenzene in toluene solution shows that formation of a type I contact occurs.

The synthesis of 3,5-disubstituted cyclometalated iridium(iii) hydrido complexes of the type [3,5-R(POCOP)IrHX] (3,5-R(POCOP) = κ-CHR-2,6-(OPtBu) with R = t-Bu, COOMe; X = Cl, H) is described. All complexes were investigated in the catalytic dehydrogenation of hydrazine borane and compared with the unsubstituted compounds [(POCOP)IrHX] (X = Cl, H). All catalysts are highly active and recyclable, clearly maintaining hydrogen production activity. The dehydrogenation products were structurally characterised by solid state NMR and FTIR spectroscopy. Experimental observations were complemented by a dispersion-corrected DFT study to rationalise the mechanism of hydrazine borane dehydrogenation.

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The reaction of 1,3‐dimercaptobenzene with iPr2PCl in the presence of the base NaH, furnishes the symmetric ligand [C6H4‐1,3‐(SPiPr2)2] (1a). The direct reaction of this ligand as well as of the literature‐known nonsymmetric ligand [C6H4‐1‐(SPiPr2)‐3‐(OPiPr2)] (1b) with NiCl2 affords the symmetric bis(thiophosphinito) PSCSP pincer complex [{C6H3‐2,6‐(SPiPr2)2}NiCl] (2a) as well as the phosphinito–thiophosphinito POCSP pincer complex [{C6H3‐2‐(SPiPr2)‐6‐(OPiPr2)}NiCl] (2b). Both complexes were fully characterised and their catalytic performance in Kumada coupling of aryl halides and p‐tolylmagnesium bromide under mild conditions was evaluated.

An isostructural series of nickel, palladium and platinum halido complexes of the type [(POCOP)MX] [POCOP = κ 3 -C 5 H 3 -2,6-(OPtBu 2 ) 2 ; X = F, Cl, I] was prepared and fully characterised. Molecular structures of complexes 1-I, 2-I, 3-Cl and 3-I are reported and show the typical distorted square-planar coordination geometries. In the presence of HF, Ni and Pt fluorido [a] Scheme 3. Synthesis of complex 2-Cl. Scheme 4. Synthesis of complexes 2-I and 2-F from 2-Cl.

What is the most significant result of this study? Our paper reports on novel P-N-P-containing compounds which can be prepared by reducing N,N-bis{chloro(aryl)-phosphino}-amines. Due to the variation of the substituents at the phosphorus or nitrogen centers, the solvents and reducing agents, we were able to develop selective syntheses for several cyclic compounds. We consider the formation of new PN rings as the essence of this paper.

Angiogenesis plays a central role in the healing process following acute myocardial infarction. The PET tracer [68Ga]-NODAGA-RGD, which is a ligand for the αvβ3 integrin, has been investigated for imaging angiogenesis in the process of healing myocardium in both animal and clinical studies. It’s value as a prognostic marker of functional outcome remains unclear. Therefore, the aim of this work was to establish [68Ga]-NODAGA-RGD for imaging angiogenesis in the murine infarct model and evaluate the tracer as a predictor for cardiac remodeling in the context of cardiac stem cell therapy. [68Ga]-NODAGA-RGD PET performed seven days after left anterior descending coronary artery (LAD) occlusion in 129S6 mice showed intense tracer accumulation within the infarct region. The specificity was shown in a sub-group of animals by application of the competitive inhibitor cilengitide prior to tracer injection in a subgroup of animals. Myocardial infarction (MI) significantly reduced cardiac function and resulted in pronounced left ventricular remodeling after three weeks, as measured by cardiac MRI in a separate group. Cardiac induced cells (CiC) that were derived from mESC injected intramyocardially in the therapy group significantly improved left ventricular ejection fraction (LVEF). Surprisingly, CiC transplantation resulted in significantly lower tracer accumulation seven days after MI induction. Accordingly, we successfully established the PET tracer [68Ga]-NODAGA-RGD for the assessment of αvβ3 integrin expression in the healing process after MI in the mouse model. Yet, our results indicate that the mere extent of angiogenesis following MI does not serve as a sufficient prognostic marker for functional outcome.