Multinuclear aluminum cocatalysts have been obtained by the reaction of various phenols, alcohols or diols with trimethylaluminum and were used in situ or as isolated, well-defined species, for the activation of an iron(ii) or an iron(iii) pre-catalyst for the oligomerization of ethylene. The best cocatalyst candidate involves 2,2'-biphenol () in a /AlMe3 ratio of 2/3.

An orthogonal set of Cu-catalysts for the selective mono-arylation of alkyl aryl diols using aryl iodides is presented. Picolinic acid ligated copper catalyst provided phenol O-arylation only, while alkyl aryl ethers are generated by ligand-free copper catalyst in the presence of 2 equivalents NaOt-Bu.

Certain (Z)-1,5-syn-diols 2 may be converted into 2,6-trans-5,6-dihydropyrans by using phosphonium salt 4 or phosphorane 5 as dehydrating agents. A more general four step procedure converts the (Z)-1,5-syn-endiols into enantiomeric dihydropyrans ent-3 via regioselective silylation of the allylic alcohol unit followed by mesylate formation and base-promoted nucleophilic displacement.

A simple, fast, efficient and environmentally friendly method for synthesis of benzimidazole and its 2-alkyl, aryl and heteroaryl substituted derivatives was developed using zeolite HY. Two component cyclolcondensation of 1,2-phenylenediamine (o-phenylenediamine) and commercially available carboxylic acids catalyzed by zeolite HY without any solvent, under microwave irradiation led to formation...

reaction of compound 1 with thiobenzarnide or substituted selenobenzamides afforded substituted pyrrolobenzothiazole or selenazoles (2) respectively. selenium dioxide oxidation of the semicarbazone 4 with selenium dioxide gave 6- benzenesulfonyl- 4,5-dihydro-pynolo [3,2-el benzoselenadiazole (5).

The unprecedented homogeneous hydrogenation of cyclic di-esters, in particular biomass-derived glycolide and lactide, to the corresponding 1,2-diols is catalyzed by Ru(II) PNN (1) and Ru(II) CNN (2) pincer complexes under mild hydrogen pressure and (in the case of 1) neutral conditions. No racemization was observed when a chiral di-ester was used.

Oxidation of 2-hydroxy-9,10-dialkynylanthracenes resulted in highly regioselective dimerization to furnish metastable dearomatized 1,4-diketones rather than stable aromatic diols. The 1,4-diketones were converted to oxahelicenes, which exhibited strong fluorescence both in solution and solid state as well as chiroptical properties.

In this article we show synthetic pathways to [6.8](n)cyclacenes demonstrated by the de novo synthesis of [6.8](3)cyclacene as the first purely hydrocarbon cyclacene and of precursors for [6.8](4)cyclacene. The design of the de novo synthesis by exploring alternative pathways is discussed and various precursors are shown. Crucial to the synthesis of [6.8](3)cyclacene were two cyclization steps....