An efficient, general palladium catalyst for C–O bond-forming reactions of secondary and primary alcohols with a range of aryl halides has been developed. Use of a catalyst based on a single bulky biarylphosphine ligand L4 (RockPhos, soon to be commercially available) has expanded this chemistry to allow the transformation of a variety of heteroaryl halides, and for the first time, allows for t...

A. S. Shawali, M. A . A bdallah , and M. E. M. Z ay ed Department of Chemistry, Faculty of Science, University of Cairo, Giza, Egypt Reprint requests to Dr. A. S. Shawali. E-mail: [email protected] Z. Naturforsch. 55b, 546-552 (2000); received February 4. 2000 Ring-Chain Tautomerism. Heterocyclic Ring Transformation, 1,3,4-Thiadiazoles The synthesis and antimicrobial activity of a s...

The title complexes [mu-(E)-4,4'-(ethene-1,2-diyl)dipyridine-kappa(2)N:N']bis[halotris(4-methylphenyl)tin(IV)], [Sn(2)(C(7)H(7))(6)X(2)(C(12)H(10)N(2))], where halo is chloro (X = Cl) and bromo (X = Br) are isostructural. In both crystals, the molecules lie on inversion centers, and there are voids of ca 80 A(3) that could, but apparently do not, accommodate water molecules. The corresponding i...

We describe the functionalization of α-amino C-H bonds with aryl halides using a combination of nickel and photoredox catalysis. This direct C-H, C-X coupling uses inexpensive and readily available starting materials to generate benzylic amines, an important class of bioactive molecules. Mechanistically, this method features the direct arylation of α-amino radicals mediated by a nickel catalyst...

To date more than 3650 organohalogen compounds are known to be naturally produced by biogeochemical processes [1]. The current understanding of the abiotic formation of organohalogens during early diagenetic processes in soils and sediments are reviewed. Next to volatile alkyl halides and polar organohalogens such as haloacetates there is evidence that even semivolatile organohalogens (e.g. pol...

Accurate calculations are made for the hydration energies of the alkali halides, using the most recent data. These results, and the average of theoretical calculations made by others for the individual ions, are used to determine the most probable hydration energy of the individual ions. These in turn are the basis for calculating the absolute enthalpy of formation of aqueous H: 98.6 kcal/g-equ...

Copper(I) halides are employed as ‘phosphine sponges’ to sequester phosphor-ylides when using phosphine-based Grubb’s metathesis catalysis in polar protic solvents and under heat. These cuprous halides are hypothesized to significantly slow the formation of the ruthenium hydride olefin isomerization catalyst. We demonstrate their use in both cross metathesis and ring-closing metathesis.

An efficient method for the construction of fused yne-substituted aryl halides by reaction of unactivated linear tetraynes with allyl halides via domino C-C coupling and formation of C-X bonds in the presence of Pd(OAc)2/PPh3 was developed.

The various biological activities namely anthelmintic, antiarthropodal, antiviral, antimicrobial, herbicidal, antisarcoptic, acaricidal, insecticidal and miticidal activities exhibited by the hydrazonoyl halides are surveyed. Also, the uses of such halides as pesticides, weed controlling and antihypertensive agents as well as lipoxygenase and cyclooxygenase inhibitors are presented. Furthermore...