RESUMO
Variously substituted 1,3-diarylisobenzofurans have been regiospecifically prepared via palladium- and rhodium-catalysed reaction of functionalised boronic acids onto o-acylbenzaldehydes. Rhodium catalysis has furthermore been improved using microwave activation. Thus, isobenzofurans containing aryl groups substituted by halogens, unprotected amine, alcohol and even aldehyde groups, have been obtained directly in good to satisfactory yields. Divergent results have been observed when palladium-, rhodium- and MW-activated rhodium-catalysis was applied to the reaction of phenylboronic acid with an iodinated o-acylbenzaldehyde, leading principally to Suzuki coupling product and/or to iodinated isobenzofuran.
RESUMO
Efficient aerobic oxidation of benzylic compounds using NHTPPI, a new NHPI analogue, as a key catalyst combined with CuCl, have been achieved under mild conditions and using as little as 1 mol% catalyst.
RESUMO
2,2,6,6-Tetramethyl-1-piperidinyloxy catalyzes efficient oxidation of primary alcohols to aldehydes by N-chlorosuccinimide, in a biphasic dichloromethane-aqueous pH 8.6 buffer system in the presence of tetrabutylammonium chloride. Aliphatic, benzylic, and allylic alcohols are readily oxidized with no overoxidation to carboxylic acids. Secondary alcohols are oxidized to ketones with a much lower efficiency. Very high chemoselectivities are observed when primary alcohols are oxidized in the presence of secondary ones. Primary-secondary diols are selectively transformed into hydroxy aldehydes, with, in some cases, no detectable formation of the isomeric keto alcohols.
RESUMO
The emission properties of a series of substituted 1,3-diarylisobenzofurans have been studied. Most compounds exhibit very intense emission in the nanosecond timescale at room temperature as well as at 77 K. The room temperature emission is attributed to the deactivation of a twisted intramolecular charge transfer excited state, based on its energy, shape and solvent dependence. The experimental results are strongly supported by a theoretical study on one representative compound. The DFT/TD-DFT calculations demonstrate that the initial excited state relaxes toward a twisted structure.
RESUMO
A convenient, versatile, and regiospecific synthesis of functionalized 1,3-diarylisobenzofurans has been developed. It involves chemoselective addition of arylmagnesium reagents to the aldehyde function of o-aroylbenzaldehydes, themselves readily obtained by lead tetraacetate oxidation of N-aroylhydrazones of salicylaldehydes. Various functional groups, including nitro, iodo, or ester functionalities, have thus been positioned with complete regiospecificity on the 1,3-diphenylisobenzofuran backbone.
RESUMO
None of the already described CK2 inhibitors did fulfill the requirements for successful clinical settings. In order to find innovative CK2 inhibitors based on new scaffolds, we have performed a high-throughput screening of diverse chemical libraries. We report here the identification and characterization of several classes of new inhibitors. Whereas some share characteristics of previously known CK2 inhibitors, others are chemically unrelated and may represent new opportunities for the development of better CK2 inhibitors. By combining structure-activity relationships with a docking procedure, we were able to determine the binding mode of these inhibitors. Interestingly, beside the identification of several nanomolar ATP-competitive inhibitors, one class of chemical inhibitors displays a non-ATP competitive mode of inhibition, a feature that suggests that CK2 possess distinct druggable binding sites. For the most promising inhibitors, selectivity profiling was performed. We also provide evidence that some chemical compounds are inhibiting CK2 in living cells. Finally, the collected data allowed us to draw the rules about the chemical requirements for CK2 inhibition both in vitro and in a cellular context.