Catalytic Three‐Component Domino Reaction for the Preparation of Trisubstituted Oxazoles

Multicomponent reactions are attractive for assembling functionalized heterocyclic compounds. To this end, an efficient gold‐catalyzed three‐component domino reaction to form oxazoles directly from imines, alkynes, and acid chlorides is presented. The reaction proceeds in a single synthetic step by using a gold(III)–N,N′‐ethylenebis(salicylimine) (salen) catalyst to give trisubstituted oxazoles in up to 96 % yield. The substrate scope, a mechanistic study exploring the role of the gold catalyst, and the synthetic applications of the oxazole products are discussed.     

Transparent thin films and monoliths synthesized from fullerene doped mesoporous silica: evidence for embedded monodispersed C60

Thin films and monoliths of mesostructured silica containing embedded monodispersed molecules of C60 may be prepared via a sol-gel route in which the C60 is added during the synthesis or via post-synthesis adsorption; evidence from diffuse reflectance spectroscopy suggests that the embedded C60 exist predominantly in monomeric form.     

Influence of electrode rotation on the growth and impedance of a low band gap conducting polymer

Rotation of the electrode during the electrochemical polymerization of delta4,4'-di-cyclopenta[2,1-b;3',4'-b']-dithiophene results in enhanced rates of film growth on the electrode and changes in morphology from dominantly fibrilar to globular structures. The impedance of the resulting films shows their ionic conductivities to be higher than their electronic conductivities. Rotating the electrode during growth enhances electronic conductivities by as much as 2 orders of magnitude, and this is attributed to the dominance of growth of the polymer on the electrode surface (grafting) over the precipitation of material from the diffusion layer.     

New robust passivity criteria for stochastic fuzzy BAM neural networks with time-varying delays

In this paper, we consider the problem of passivity analysis issue for a class of stochastic fuzzy BAM neural networks with time varying delays. By employing the idea of delay-fractioning technique and Lyapunov stability theory, a new set of sufficient conditions are derived in terms of linear matrix inequalities for obtaining the passivity condition of the considered neural network model. First, we derive the passivity condition for stochastic fuzzy BAM neural networks with time varying delays and then the result is extended to the case with uncertainties. Two numerical examples are given to illustrate the effectiveness and conservatism of the obtained results.