Iodofluorination of alkenes and alkynes promoted by iodine and 4-iodotoluene difluoride

—It was found that a mixture of molecular iodine and 4-iodotoluene difluoride are useful to generate in situ the couple IF that was able to add in a Markovnikov fashion and with prevalent anti-stereoselectivity to various alkenes and alkynes

Two aminobenzothiazole derivatives for Pd(II) and Zn(II) coordination

Two derivs. of 2-aminobenzothiazole are reported: an imine I (Im) potentially able to generate on deprotonation a mononeg. ligand moiety and an amide II (Am) suited to metal coordination. Both were used for producing tetracoordinated complexes of Zn(II) (ZnIm2 and ZnAm2Cl2) and Pd(II) (PdIm2 and PdAm2). The thermodn. and optical properties of ligands and complexes were analyzed by calorimetry, polarizing microscopy and an x-ray technique. In particular, the fluorescence properties of ligands and complexes were explored

Glycosylation reaction using anomeric selenoxides

Oxidation of anomeric selenides, obtained from the radical azido phenylselenenylation of glycals, generates in situ extremely reactive glycosyl donors. When a 2-azido-2-deoxy-1-phenylselenomannoside is treated at a low temperature with perfluoro-cis-2,3-dialkyloxaziridine in the presence of a glycosyl acceptor, a (1-6)-β-linked mannopyranoside is obtained free from its α-isomer. 2-Phenyl-4,5-(3,4,6,-tri-O-methyl-1,2-di-deoxy-β-D-mannopyrano)-[2,1-d]-2-o xazoline, is isolated when 2-benzamido-2-deoxy-1-phenylselenomannoside is allowed to react with m-CPBA in dichloromethane

NEW LC THIOPHENE BASED ORGANIC AND COORDINATION POLYMERS

Many five membered etherocyclic rings attract attention as their non planar structures leads to a variety of desirable unique features in the so called “banana” mesogens, for their slightly bent structures. Thiophene in particular has emerged as a core unit that is receiving increasing attention, both in organic and in coordination compounds. Thiophene based polymers are often employed in optics and opto-electronics for its unique properties. Here we present the synthesis of two types of polymers. Their LC behaviour is investigated. The polymers are characterized by the presence of flexible chains and of a thiophene unit in the rigid molecular segment: -C6H4-CH=N-2,5-(C4H2S)-N=N-C6H4-. One type of polymer is a simply organic main-chain LC polymer, eventually bearing functions suited for crosslinking. The second type is a coordination polymer of Pd(II) or Cu(II) where the coordination environment is given by two chelating N,O- moieties

Facile synthesis of new Pd(II) and Cu(II) based metallomesogens from ligands containing thiophene rings

Very simple synthetic procedures, involving use of tin/amine complex afford two new mesogenic thiophene derivatives. These can chelate palladium(II) or copper(II) producing the corresponding metallomesogens. The liquid crystal properties of all compounds were investigated by calorimetry, polarizing microscopy and X-ray diffraction techniques. Molecular and crystal structure of one ligand and two complexes were analyzed by single crystal X-ray diffraction. Connections between structural features and phase behaviour are discussed