CO-Driven N-Formylation/N-Methylation of Amines Using C-Scorpionate Metal Complexes.

C-scorpionate metal complexes, specifically, [NiCl(tpm)]·3HO, [CoCl(tpm)]·3HO and [PdCl(tpm)] [tpm = hydrotris(1H-pyrazol-1-yl)methane], were effective in the N-formylation and N-methylation of amines using carbon dioxide, as carbon source, in the presence of sodium borohydride. Various parameters were studied, including reaction time, temperature, solvent volume, presence of additives, and catalyst amount. These parameters were found to have a significant impact on the selectivity of the product.

Borohydride Ionic Liquids as Reductants of CO in the Selective N-formylation of Amines.

Borohydride imidazolium ionic liquids, [IL]BH, used for the first time as reductants in the N-formylation of various amines with CO, provided an excellent yield of formamides. Under the same conditions, 5 bar CO and 80 °C, NaBH produced a mixture of N-formylated and N-methylated products in a ratio of 1 : 2. An alternative approach, based on the addition of halide imidazolium salts ([IL]Cl or [IL]Br) to the reactions of amine with NaBH and CO, resulted in a significant increase of selectivity to formamide.

New Palladium - ZrO Nano-Architectures from Thermal Transformation of UiO-66-NH for Carbonylative Suzuki and Hydrogenation Reactions.

The new nanocomposites, Pd/C/ZrO , PdO/ZrO and Pd/PdO/ZrO , were prepared by thermal conversion of Pd@UiO-66-Zr-NH (MOF) in nitrogen or air atmosphere. The presence of Pd nanoparticles, uniformly distributed on the ZrO or C/ZrO matrix, was evidenced by transmission electron microscopy, scanning electron microscopy (SEM), Raman and X-ray Photoelectron Spectroscopy (XPS) methods. All pyrolysed composites retained the shape of the MOF template.

Immobilization of Rh(I) precursor in a porphyrin metal-organic framework - turning on the catalytic activity.

Two model porphyrin metal-organic frameworks were used for the incorporation of Rh(i) species by a post-synthetic metallation under mild conditions. As a result, new rhodium MOFs (Rh/MOFs), Rh/PCN-222 and Rh/NU-1102, were synthesized and structurally characterized. To illustrate the potential of this catalytic platform, we use Rh/MOFs as phosphine-free heterogeneous catalysts in the hydrogenation of unsaturated hydrocarbons under mild reaction conditions (30 °C and 1 atm H2).

Photoactive Liposomal Formulation of PVP-Conjugated Chlorin e6 for Photodynamic Reduction of Atherosclerotic Plaque.

Background: Liposomes serve as delivery systems for biologically active compounds. Existing technologies inefficiently encapsulate large hydrophilic macromolecules, such as PVP-conjugated chlorin e6 (Photolon). This photoactive drug has been widely tested for therapeutic applications, including photodynamic reduction of atherosclerotic plaque.

Heck Transformations of Biological Compounds Catalyzed by Phosphine-Free Palladium.

The development and optimization of synthetic methods leading to functionalized biologically active compounds is described. Two alternative pathways based on Heck-type reactions, employing iodobenzene or phenylboronic acid, were elaborated for the arylation of eugenol and estragole. Cinnamyl alcohol was efficiently transformed to saturated arylated aldehydes in reaction with iodobenzene using the tandem arylation/isomerization sequential process.

Palladium catalyzed heck arylation of 2,3-dihydrofuran-effect of the palladium precursor.

Heck arylation of 2,3-dihydrofuran with iodobenzene was carried out in systems consisting of different palladium precursors (Pd2(dba)3, Pd(acac)2, PdCl2(cod), [PdCl(allyl)]2, PdCl2(PhCN)2, PdCl2(PPh3)2) and ionic liquids (CILs) with L-prolinate or L-lactate anions. All the tested CILs caused remarkable increases of the conversion values and in all of the reactions 2-phenyl-2,3-dihydrofuran (3) was obtained as the main product with a yield of up to 59.2%.

Palladium-catalyzed asymmetric Heck arylation of 2,3-dihydrofuran--effect of prolinate salts.

Chiral ionic liquids (CILs) containing L-prolinate and L-lactate anions and non-chiral quaternary ammonium cations were employed in the palladium catalyzed enantioselective Heck arylation of 2,3-dihydrofuran with aryl iodides (iodobenzene, 4-iodotoluene, 2-iodoanisole, 4-iodoanisole, 4-iodoacetophenone). In all the reactions 2-aryl-2,3-dihydrofuran (3) was obtained as the main product with the yield up to 52% at the total conversion reaching 83%. Product 3, 2-phenyl-2,3-dihydrofuran, was obtained with excellent enantioselectivity (>99% ee) in a 6 h reaction with tetrabutylammonium L-prolinate.

PEPPSI-type palladium complexes containing basic 1,2,3-triazolylidene ligands and their role in Suzuki-Miyaura catalysis.

A series of PEPPSI-type palladium(II) complexes was synthesized that contain 3-chloropyridine as an easily removable ligand and a triazolylidene as a strongly donating mesoionic spectator ligand. Catalytic tests in Suzuki-Miyaura cross-coupling reactions revealed the activity of these complexes towards aryl bromides and aryl chlorides at moderate temperatures (50 °C). However, the impact of steric shielding was the inverse of that observed with related normal Nheterocyclic carbenes (imidazol-2-ylidenes) and sterically congested mesityl substituents induced lower activity than small alkyl groups.

cis-Dichloridobis[tris-(2-methyl-phen-oxy)phosphane-κP]palladium(II).

In the title compound, [PdCl(2)(C(21)H(21)O(3)P)(2)], the Pd atom adopts a slightly distorted square-planar coordination geometry, with pairs of the equivalent ligands in cis positions. Adjacent mol-ecules are linked by weak C-H⋯Cl hydrogen bonds. The crystal structure is additionally stabilized by π-π stacking inter-actions between the aromatic rings [shortest centroid-centroid distance = 3.

Chlorido(1,2-dimethyl-1H-imidazole-κN){2-[(diphen-oxy-phosphan-yl)-oxy]phenyl-κC,P}palladium(II).

The Pd atom in the title compound, [Pd(C(18)H(14)O(3)P)Cl(C(5)H(8)N(2))], adopts a slightly distorted square-planar coordination geometry, with the metallated carbon positioned trans to the Cl atom. The crystal structure is stabilized by several weak C-H⋯O and C-H⋯Cl hydrogen-bond inter-actions. One of the phenyl rings is disordered over two almost equally occupied sites.

4,4,5,5-Tetra-methyl-1,3,2λ-dioxa-phospho-lan-2-one.

The five-membered ring in the title compound, C(6)H(13)O(3)P, exists in an envelope conformation with one of the ring C atoms at the flap position. The coordination geometry around the P atom is a distorted tetra-hedron. The crystal structure is stabilized by several weak C-H⋯O and P-H⋯O hydrogen bonds, forming a three-dimensional network.

trans-Dichloridobis(3,5-dimethyl-pyridine-κN)(ethano-lato-κO)oxido-rhenium(V).

The title compound, [Re(C(2)H(5)O)Cl(2)O(C(7)H(9)N)(2)], was crystallized from ethanol. The crystal structure of this complex contains a Re(V) atom in a slightly distorted octahedral coordination geometry with pairs of equivalent ligands in trans positions. Adjacent complex mol-ecules are linked by weak C-H⋯Cl hydrogen bonds.

Palladium(0) deposited on PAMAM dendrimers as a catalyst for C-C cross coupling reactions.

PAMAM dendrimers of generations G2-G3 as well as a partially substituted derivative of generation G4 and a low-molecular-weight tricyclic ligand 4 were used to bind Pd(0) nanoparticles. The obtained adducts were tested as catalysts for C-C cross-coupling reactions, such as the Suzuki-Miyaura, Hiyama, Heck and Sonogashira reaction. The highest yields of the coupling product, diphenylacetylene, were obtained with all the catalysts studied in the Sonogashira coupling performed in ethanol with K₂CO₃ as base.

Selective Heck arylation of cyclohexene with homogeneous and heterogeneous palladium catalysts.

Palladium catalysts containing Pd(II) supported on Al2O3 and alumina-based mixed oxides, Al2O3-ZrO2, Al2O3-CeO2, and Al2O3-Fe2O3, are very effective in the Heck coupling of iodobenzene with cyclohexene in DMF solution. The best results, up to 81% of monoarylated products with a selectivity to 4-phenylcyclohexene (3) close to 90% were obtained with KOH as a base. The catalytic activity of palladium supported on alumina-based oxides was compared with that of homogeneous precursors, such as Pd(OAc)2 and PdCl2(PhCN)2, used in [Bu4N]Br as the reaction medium.

A chloro-bridged dinuclear phosphinitopalladium complex, di-mu-chloro-bis[(diphenoxyphosphinite-kappaP)(diphenoxyphosphinito-kappaP)palladium(II)].

The title compound, [Pd2(C12H10O3P)2Cl2(C12H11O3P)2], consists of a dinuclear mu-chloro-bridged palladium unit with two diphenoxyphosphinite groups per Pd atom, linked together by a hydrogen bond. The asymmetric unit contains one half of the molecule, with the other half generated by an inversion centre. The geometry around the P atoms may be described as distorted tetrahedral.

Chemistry of palladium phosphinite (PPh(2)(OR)) and phosphonite (P(OPh)(2)(OH)) complexes: catalytic activity in methoxycarbonylation and Heck coupling reactions.

The new phosphinite and phosphonite complexes (1-8) are very efficient catalysts for the methoxycarbonylation of iodobenzene and Heck cross-coupling of bromobenzene with butyl acrylate. High catalytic activity of these complexes can be explained by their in situ transformations during the reaction, stimulated by the presence of water, acid (HCl) or base (NEt(3)). Hydrolysis of phosphinite palladium complexes of the form trans-PdCl(2)[PPh(2)(OR)](2) (R = C(6)F(5), 2, (t)Bu 3, or O-menthyl 4) results in the formation of the dimeric complex [mu-ClPd(PPh(2)OH)(PPh(2)O)](2) 5, which is deprotonated by NEt(3), producing a polymeric complex of formula [Pd(P(O)PPh(2))(2)](n) 8.