The catalytic ability of ZrO(2)/SO(4)(2-) to promote solventless three-component condensation reactions of a diversity of aromatic aldehydes, urea or thoiurea and ethyl acetoacetate was studied. Products resulting from Hantzsch and/or Biginelli multi-component reactions are obtained in the presence of solid acid catalysts using the same reactants but different temperature conditions. The sulfat...

1,3-dibromo-5,5-dimethylhydantoin (dbh), as a cheap and commercially available reagent, is efficiently able to catalyze the synthesis of polyhydroquinoline derivatives and 12-aryl-8,9,10,12-tetrahydro[a] xanthene-11-ones via one-pot multi-component reactions. this novel synthetic method has the advantages of low cost and availability of the catalyst, short reaction times, high to excellent yiel...

A facile and highly efficient protocol was applied successfully to synthesize 4H-pyrimido[2,1,b]benzimiazoles and 4H-pyrimido[2,1,b]benzothiazoles through one-pot three-component cyclocondensation reactions of 2-aminobenzimidazole or 2-aminobenzothiazole with dimedone and aromatic aldehydes in the presence of guanidinium chloride under solvent-free conditions. The reactions us...

While some sequential electrophilic aromatic substitution reactions, known as tandem/domino/cascade reactions, have been reported for the construction of aromatic single skeletons, one of the most interesting and challenging possibilities remains the one-pot build-up of a complex aromatic molecule from multiple starting components, i.e., ultimately multi-component electrophilic aromatic substit...

The discovery of novel chemical reactions or reaction sequences that are able to generate useful chemical products may be regarded as the heart of organic chemistry. We present here concepts and methods on how to find and explore new multi component reactions, especially with automated combinatorial methods. This "combinatorial reaction finding" provides also a powerful tool to the understandin...

Optical biosensors are often used to measure kinetic rate constants associated with chemical reactions. Such instruments operate in the surface-volume configuration, in which ligand molecules are convected through a fluid-filled volume over a surface to which receptors are confined. Currently, scientists are using optical biosensors to measure the kinetic rate constants associated with DNA tran...

We present a simple, two-component model for the charged mu'ltiplicity associated with the observed particle in an inclusive reaction. At small p T' the scattering is ascribed to a coherent or I* soft " component, whereas at large pT the production mechanism is assumed to be incoherent or " hard. l1 At fixed incident energy and missing mass, the pT-dependence of Kc is given by the relative weig...

We present a multistep direct reaction theory for analyzing nucleon-induced reactions to the continuum for incident energies up to 200 MeV. Two principal advances in multistep direct theory are studied: (1) A microscopical approach for calculating DWBA transitions to the continuum, where transitions to all accessible 1p1h shell model states are explicity determined; (2) A two-component formulat...

The analysis of kinetic data monitored using spectroscopic techniques and its resolution into its unknown components is described. Independent Component Analysis (ICA) can be considered a calibration free technique with the outcome of the analyses being the spectral profiles of the unknown species. This enables the realisation of qualitative information concerning the identification of the numb...

We consider deep-inelastic lepton scattering, Drell-Yan lepton pair and heavy quark production in the reference frame of the target. These reactions traditionally treated as hard have, however, a substantial leading twist soft contribution. One of the manifestations of such a soft component, nuclear shadowing, is overviewed. ∗Invited talk at the Workshop Hirschegg’95: Dynamical Properties of Ha...