Are activation barriers of 50-70 kcal mol accessible for transformations in organic synthesis in solution?

High-temperature organic chemistry represents a transformative approach for accessing reaction pathways previously considered unattainable under conventional conditions. This study focuses on a high-temperature synthesis as a powerful method for performing solution-phase organic reactions at temperatures up to 500 °C. Using the isomerization of -substituted pyrazoles as a model reaction, we demonstrate the ability to overcome activation energy barriers of 50-70 kcal mol, achieving product yields up to 50% within reaction times as short as five minutes.

Yellow to blue switching of fluorescence by the tuning of the pentaphenylphosphole structure: phosphorus electronic state ring conjugation.

The interaction between diphenylacetylene and dichlorophenylphosphine under various conditions is a simple method for the preparation of pentaphenylphosphole derivatives exhibiting fluorescence properties. Depending on the electronic state of the various centers of the phospholic structure, it was possible to obtain molecules with fluorescence, as in the blue area for 1,2,3,4,5-pentaphenyl-2,5-dihydro-phosphole-1-oxide (HPPPO), in the yellow area for 1,2,3,4,5-pentaphenylphosphole-1-oxide (PPPO) and in the cyan area for 1,2,3,4,5-pentaphenylphosphole (PPP). The effect of the structure and π-conjugation on the optical properties of these compounds was studied using PPP derivatives as examples.