Pyrazole-tethered arylphosphine ligands for Suzuki reactions of aryl chlorides: how important is chelation?

One-pot activation-alkynylation-cyclization synthesis of 1,5-diacyl-5-hydroxypyrazolines in a consecutive three-component fashion

A consecutive three-component activation–alkynylation–cyclization reaction of (hetero)aryl glyoxylic acids, oxalyl chloride, arylacetylenes, and hydrazides efficiently forms 1,5-diacyl-5-hydroxypyrazolines in moderate to good yields. The structures were unambiguously corroborated by comprehensive NMR spectroscopy and X-ray structure analyses of selected derivatives.

Hetero-bimetallic cooperative catalysis for the synthesis of heteroarenes

Review covering the synthesis of 5- and 6-membered as well as condensed heteroarenes, focussing on the combinations in cooperative catalytic systems in strategies used to achieve selectivity and also highlights the mode of action for the cooperative catalysis leading to the synthesis of commercially and biologically relevant heteroarenes.

A delicate case of unidirectional proton transfer from water to an aromatic heterocyclic anion

One of the hydroxyl modes of the surrounding water molecules with the lowest stretching frequency facilitates the proton transfer from water to an anion.

Sequential palladium catalyzed coupling–cyclocondensation–coupling (C3) four-component synthesis of intensively blue luminescent biarylsubstituted pyrazoles

Highly blue-fluorescent 1-, 3-, and 5-biarylsubstituted pyrazoles can be efficiently prepared by a MW-assisted consecutive four-component synthesis based upon a sequential Pd-catalyzed Sonogashira coupling–condensation–Suzuki coupling (C³) process.

Palladium catalyzed decarboxylative acylation of arylboronic acid with ethyl cyanoacetate as a new acylating agent: synthesis of alkyl aryl ketones

The versatile, one-pot synthesis of a series of alkyl aryl ketones is described using ethyl cyanoacetate as a new acylating agent.

Synthesis, characterization, and application of palladium complexes containing 8-quinolylphosphinite ligands

Palladium complexes containing 8-quinolylphosphinite ligands have been synthesized and characterized. Their solid state structures were determined by single-crystal X-ray diffraction. They were found to be active catalysts for Suzuki coupling reactions of phenylboronic acid and various aryl halides.

Ru and Os complexes containing a P,N-donor heterotopic ligand: the effect of solvent on stereochemistry

Ruthenium and osmium complexes of the general formula MCl 2(PyP) 2 (where PyP is the P,N- donor ligand 1-(2-diphenylphosphinoethyl)pyrazole) were synthesized from MCl 2(PPh 3) 3 (where M = Ru or Os). Three of the five possible stereoisomers of RuCl 2(PyP) 2 were synthesized and characterized in solution by multinuclear NMR spectroscopy, and the structure of these in the solid state was determined by X-ray crystallography. Two of the analogous Os isomers were also synthesized. It was found that different solvents induced isomerization between these stereoisomers, indicating either lability of the chloride anion or hemilability of the PyP ligand. Bimetallic complexes of the general formula [Ru(mu-Cl)(PyP) 2] 2[X] 2 were synthesized from chloride abstraction from RuCl 2(PyP) 2 using either silver (X = OSO 2CF 3, BF 4) or sodium (X = BPh 4) salts. The osmium analogue of the Ru bimetallic complexes, [Os(mu-Cl)(PyP) 2] 2[BPh 4] 2, was also synthesized. Solid-state structures were obtained using X-ray crystallography for the osmium bimetallic complex and the ruthenium bimetallic complex where X = OSO 2CF 3. The hemilability of PyP was demonstrated through the synthesis of RuCl 2(CO)(kappa (1)- P-PyP)(kappa (2)- P, N-PyP), which contains one pendant PyP ligand, bound through the P-donor atom.