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

Homogén katalízis többfázisú folyadékrendszerekben = Homogeneous catalysis in multiphase liquid systems

Megvalósítottuk CaCO3 és MgCO3 homogénkatalitikus hidrogénezését, vizes közegben CO2/H2 atmoszférában. Felismertük, hogy a Rh(I) és Ru(II) vízoldható foszfinkomplexei jó hatásfokkal katalizálják a H2/D2O és a D2/H2O közötti H-D izotópcserét. Alkinek kétfázisú szelektív hidrogénezését valósítottuk meg Ru(II) vízoldható foszfinkomplexeivel és megállapítottuk, hogy a diszubsztituált alkinek hidrogénezésének sztereoszelektivitása erősen függ a vizes fázis pH-jától. Elsők között állítottunk elő N-heterociklusos karbén ligandumú, vízoldható Rh(I)- és Ru(II)-komplexeket, melyek katalizálják alkének, aldehidek és ketonok hidrogénezését tovább allil-alkoholok redox izomerizációját a megfelelő ketonná ill. aldehiddé. Számos esetben kimutattuk, hogy vizes közegben a foszfin vagy karbén ligandumú kloro-komplexek klorid disszociációt szenvednek, ami kationos komplexek spontán képződéséhez és ezzel a katalitikus sajátságok megváltozásához vezet. Lipid membránok homogénkatalitikus hidrogénezésében megállapítottuk az egyedi lipidek reaktivitását. Kvantumkémiai számításokat végeztünk a vizes közeg hatásának leírására a fémorganikus katalízisben és megállapítottuk, hogy legalább három H2O molekulából álló klasztert kell tekinteni amikor a víz koordinációját vizsgáljuk. A katalitikusan aktív fémkomplexeket szilárd hordozóra rögzítettük és sikeresen alkalmaztuk alkének, alkinek, aldehidek, szteroidok szelektív hidrogénezésében mind szuszpenzióban, mind áramlásos mikroreaktorban. | A method was developed for the homogeneous catalytic hydrogenation of CaCO3 and MgCO3 in aqueous media under a H2/CO2 atmosphere. It was established that water-soluble phosphine complexes of Rh(I) and Ru(II) efficiently catalyze the H/D exchange in H2/D2O and D2/H2O. Alkynes were selectively hydrogenated in aqueous organic biphasic systems with water-soluble Ru(II)-phosphine catalysts, where the stereoselectivity of the hydrogenation of disubstituted alkynes is strongly pH-dependent. Hitherto uknown water-soluble N-heterocyclic carbene complexes of Rh(I) and Ru(II) were synthetized and applied for the catalysis of hydrogenation of alkenes, alkynes, aldehydes and ketones, as well as for the redox isomerization of allylic alcohols. It was found in several cases, that in aqueous solution chloride-containing phosphine or carbene complexes undergo chloride dissociation with the spontaneous formation of cationic complexes. The individual reactivities of the constituent lipids in the hydrogenation of liposomes were established. Quantum chemical calculations were performed to study the effect of water in aqueous organometallic catalysis and it was established that clusters of at least three H2O molecules should be considered when modelling the coordination of water. The catalytically active metal complexes were heterogenized on solid supports and succesfully used for selective hydrogenations of alkynes, aldehydes and steroids both in suspension and in a microfluidic flow reactor

A novel 1,3,5-triaminocyclohexane-based tripodal ligand forms a unique tetra(pyrazolate)-bridged tricopper(II) core: solution equilibrium, structure and catecholase activity

A polydentate tripodal ligand forms a series of tricopper(ii) complexes, that feature unique pyrazolate-bridged linear core. The Cu3H−3L2complex is an efficient catecholase mimic with a surprisingly low pH optimum at pH = 5.6.</p

Stereoselective coordination: a six-membered P,N-chelate tailored for asymmetric allylic alkylation.

Six-membered chelate complexes [Pd()Cl2], () and [Pd()(eta(3)-PhCHCHCHPh)]BF4, () of P,N-type ligands , ((2S,4S)-2-diphenyl-phosphino-4-isopropylamino-pentane) and , ((2S,4S)-2-diphenyl-phosphino-4-methylamino-pentane) have been prepared. The Pd-complexes have been characterized in solution by 1D and 2D NMR spectroscopy. The observed structures were confirmed by DFT calculations and in the case of also by X-ray crystallography. Unexpectedly, the coordination of the all-carbon-backbone aminophosphine resulted in not only a stereospecific locking of the donor nitrogen atom into one of the two possible configurations but also the conformation of the six-membered chelate rings containing three alkyl substituents was forced into the same single chair structure showing the axially placed isopropyl group on the coordinated N-atom. The stereodiscriminative complexation of led to the formation of a palladium catalyst with a conformationally rigid chelate having a configurationally fixed nitrogen and electronically different coordination sites due to the presence of P and N donors. The stereochemically fixed catalyst provided excellent ee's (up to 96%) and activities in asymmetric allylic alkylation reactions. In contrast, the chelate rings formed by exist in two different chair conformations, both containing axial methyl groups, but with the opposite configurations of the coordinated N-atom. Pd-complexes of provided low enantioselectivities in similar alkylations, therefore emphasizing the importance of the stereoselective coordination of N-atoms in analogous P-N chelates. The factors determining the coordination of the ligands were also studied with respect to the chelate ring conformation and the nitrogen configuration

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