Structure and dynamics of the excited states of 1,3-diarylisobenzofurans: an experimental and theoretical study.

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.

Regiospecific synthesis of functionalised 1,3-diarylisobenzofurans via palladium- and rhodium-catalysed reaction of boronic acids with o-acylbenzaldehydes under thermal or microwave activation.

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.

Iodomethyl group as a hydroxymethyl synthetic equivalent: application to the syntheses of D-manno-hept-2-ulose and l-fructose derivatives.

The one-carbon elongation of aldoses to ketoses using iodomethyllithium as the key reagent in the homologation step is exemplified by the preparation of two carbohydrates of chemical and biological interests: d-manno-hept-2-ulose from d-mannose and l-fructose from l-arabinose.