The first synthesis of 3-deoxyoripavine and its utilization in the preparation of 10-deoxyaporphines and cyprodime

The synthesis of 3-deoxyoripavine (7) was realized as a novel and promising intermediate towards the synthesis of the important class of dopaminergic and/or serotonergic 10- deoxyaporphines and the special pharmacological tool µ opioid antagonist cyprodime. Generally, the preparation of these valuable biologically active compounds was achieved in remarkable yields

Synthesis and characterization of novel PEPPSI type bicyclic (alkyl)(amino)carbene (BICAAC)-Pd complexes

A series of bicyclic alkylamino carbenes (BICAAC) (where N-aryl = dipp, mes, 2,6-dimethyl-4-(dimethylamino)phenyl, 5a–d) and their novel air- and moisture-resistant pyridine (pyridine, 4-dimethylaminopyridine) containing palladium Pd(II) complexes (6a–e) were synthetized and characterized. As novel examples of the PEPPSI (“pyridine enhanced precatalyst preparation stabilization and initiation”)-Pd compounds, the reported complexes have shown high activity in Mizoroki–Heck coupling reaction even at as low as 100 ppm loading (TON up to 10000). Kinetic studies revealed that reactions carried out in the presence of elemental mercury resulted decrease in activity. It indicates that the coupling reaction may have both molecular and Pd(0)-mediated catalytic paths. © 2022 The Author

Catalytic Decomposition of Long‐Chain Olefins to Propylene via Isomerization‐Metathesis Using Latent Bicyclic (Alkyl)(Amino)Carbene‐Ruthenium Olefin Metathesis Catalysts

One of the most exciting scientific challenges today is the catalytic degradation of non‐biodegradable polymers into value‐added chemical feedstocks. The mild pyrolysis of polyolefins, including high‐density polyethylene (HDPE), results in pyrolysis oils containing long‐chain olefins as major products. In this paper, novel bicyclic (alkyl)(amino)carbene ruthenium (BICAAC−Ru) temperature‐activated latent olefin metathesis catalysts, which can be used for catalytic decomposition of long‐chain olefins to propylene are reported. These thermally stable catalysts show significantly higher selectivity to propylene at a reaction temperature of 75 °C compared to second generation Hoveyda–Grubbs or CAAC−Ru catalysts under ethenolysis conditions. The conversion of long‐chain olefins (e.g., 1‐octadecene or methyl oleate) to propylene via isomerization‐metathesis is performed by using a (RuHCl)(CO)(PPh(3))(3) isomerization co‐catalyst. The reactions can be carried out at a BICAAC−Ru catalyst loading as low as 1 ppm at elevated reaction temperature (75 °C). The observed turnover number and turnover frequency are as high as 55 000 and 10 000 mol(propylene) mol(catalyst) (−1) h(−1), respectively

Solution equilibria and structural characterisation of the transition metal complexes of glycyl-_L-cysteine disulfide

Stoichiometry, stability constants and structure of the complexes formed in the reaction of copper(II), nickel(II), zinc(II), cobalt(II) and cadmium(II) with (GlyCys)2 containing disulfide bond were determined by potentiometric, UV–Vis, NMR and EPR spectroscopic methods. The complex [Ni(GlyCys)2·H2O] was prepared in the solid state and its structure determined by single crystal X-ray diffraction method. Disulfide sulfur atoms of (GlyCys)2 were not metal-binding sites in any of the systems studied in solution or in the solid state. It was found that copper(II) is able to induce deprotonation and coordination of the peptide amide nitrogen donor atoms. This resulted in the formation of [CuL], [Cu2H−2L] and [CuH−1L]− as the major species in solution. In the case of nickel(II), cobalt(II), zinc(II) and cadmium(II) the complex [ML] predominates, and the outstanding stability of this species was explained by the formation of a macrochelate between the (NH2, CO)-coordinated five-membered chelates in solution. Crystal structure of [Ni(GlyCys)2·H2O] revealed the octahedral geometry of nickel(II) in a polymeric structure