The power of two-dimensional (2D) IR spectroscopy as a structural method with unprecedented time resolution is greatly improved by the introduction of IR polarization conditions that completely eliminate diagonal peaks from the spectra and leave only the crosspeaks needed for structure determination. This approach represents a key step forward in the applications of 2D IR to proteins, peptides,...

Furans are an important class of compounds and exhibit a diverse range of activities and properties. As such, improved synthetic access to furans is an important research goal. In the present report, a solvent- and catalyst-free reaction between 5,5-dimethyl-1,3-cyclohexanedione (dimedone), an aryl aldehyde and an isocyanide under microwave irradiation is presented. This method is significantly...

A SO3 H-containing solid acid namely SO3 H-functionalized phthalimide (SFP) was synthesized from phthalimide and chlorosulfonic acid, and identified by studying its FT-IR, 1 H and 13C NMR, Mass, XRD, TG and DTG spectra. Afterward, its catalytic activity was examined for the solvent-free condensation of dimedone (5,5-dimethyl-1,3-cyclohexanedione) (2 eq.) with arylaldehydes (1 eq.). The results ...

5. GUTFREUND, El., Trans. Faraday Sot., 61, 441 (1955). 6. WALBFI, K. A., KAUFFMAN, D. L., SAMPATH KUMAR, K. S. V., AND NEURATE, H., Proc. Natl. Ad. Sci. U. S., 51, 301 (1964). 7. WALSH, K. A., AND NEURATH, H., Proc. Nail. Acad. Sci. U. S., 52, 884 (1964). 8. MARE&GUIA, M., AND SHAW, E., Federation Proc., 22, 528 (1963). 9. CRESTFIELD, A. M., STEIN, W. H., AND MOORE, S., J. Bid. Chem., 238, 241...

Organocatalyst trityl chloride (Ph3CCl), by in situ formation of trityl carbocation with inherent instability, efficiently catalyzes the condensation of dimedone (5,5-dimethyl-1,3-cyclohexanedione) (2 equiv.) with arylaldehydes (1 equiv.) under solvent-free conditions to afford 9-aryl-1,8-dioxo-octahydroxanthenes in high to excellent yields and in relatively short reaction times. Formation of t...

an efficient synthesis of 1, 8-dioxo-octahydroxanthens and 1, 8-dioxo-decahydroacridines from the reaction of 5,5-dimethyl-1,3-cyclohexanedione (dimedone) with aromatic aldehydes bearing electron-donating or withdrawing substituents either in the presence or absence of primary amines has been described in a single pot using a catalytic amounts of aluminum tris (dodecyl sulfate) trihydrate [al(d...

SmCl3 (20 mol%) has been used as an efficient catalyst for reaction between aromatic aldehydes and 5,5-dimethyl-1,3-cyclohexanedione at 120°C to give 1,8-dioxo-octahydroxanthene derivatives in high yield. The same reaction in water, at room temperature gave only the open chain analogue of 1,8-dioxo-octahydroxanthene. Use of eco-friendly green Lewis acid, readily available catalyst and easy isol...

We report results from experiments with a pseudo-one-dimensional Belousov-Zhabotinsky reaction that employs 1,4-cyclohexanedione as its organic substrate. This excitable system shows traveling oxidation pulses and pulse trains that can undergo complex sequences of propagation failures. Moreover, we present examples for i breathing pulses that undergo periodic changes in speed and size and ii ba...