Novel bipolar bathophenanthroline containing hosts for highly efficient phosphorescent OLEDs

The electronic structures of eight bathophenanthroline derivatives were elucidated by DFT calculations, and four representatives of which CZBP, m-CZBP, m-TPAP, and BPABP were synthesized and employed as the hosts to afford highly efficient phosphorescent OLEDs. The calculated molecular orbital energies agree well with the experimental results, which further demonstrates that the localization of HOMO and LUMO at the respective hole- and electron-transporting moieties is desirable in bipolar molecular designs.     

First asymmetric total synthesis of synerazol, an antifungal antibiotic, and determination of its absolute stereochemistry

[reaction: see text] By synthesizing two possible diastereomers, the first asymmetric total synthesis of synerazol, an antifungal antibiotic, has been accomplished, allowing determination of its absolute stereochemistry. A more practical second generation route was also established. The key steps are racemization-free deprotection of a TIPS group and introduction of a methyl ether by DMD oxidation of the benzylidene moiety in a substrate having a small protecting group.     

Oxidation-Reduction Condensation a New Method for Peptide Synthesis

Organic trivalent phosphorous compounds such as trialkyl phosphites and trialkyl or triarylphosphines are well known to be powerful deoxygenation reagents and have been used in various reduction reactions. But, it is rather a new aspect to make use of their property of deoxygenation for the gsneration of active acyl groups. Since the discovery of the rezcticn of mercuric acetate with trivalent phosphorous coqounds to yield acetic anhydride, our attention has been fccused on the generation of acyl groups and several novel reactions have been found which are applicable to the preparation of acid anhydride and peptide linkages. In considering these reactions described herein, it is necessary to choose appropriate oxidation reagents together with reducing reagents (trivalent phosphcrous compounds) because these dehydration reactions essentially proceed via an oxiaation reduction process as depicted in the following scheme.     

A convenient method for the synthesis of (Z)-α-haloacrylates: Lewis base-catalyzed carbonyl olefination using α-halo-C,O-bis(trimethylsilyl)ketene acetals

A highly useful method for the stereoselective synthesis of (Z)-α-haloacrylates from various aldehydes that uses α-halogenated ethyl-C,O-bis(trimethylsilyl)ketene acetals in the presence of a Lewis base catalyst such as acetate salts was established. This procedure gives the corresponding α-halo-α,β-unsaturated esters in high yields with excellent stereoselectivity from E/Z mixtures of ketene silyl acetals under mild conditions.     

Fabrication of TiO2 using L-lysine-based organogelators as organic templates: control of the nanostructures

Using uncharged or negatively charged L-lysine-based organogelators as templates, the nanostructures of TiO2 are controllable.