Structure-based design and subsequent optimization of 2-tolyl-(1,2,3-triazol-1-yl-4-carboxamide) inhibitors of p38 MAP kinase.

A computer-aided drug design strategy leads to the identification of a new class of p38 inhibitors based on the 2-tolyl-(1,2,3-triazol-1-yl-4-carboxamide) scaffold. The tolyl triazole amides provided a potent platform amenable to optimization. Further exploration leads to compounds with greater than 100-fold improvement in binding affinity to p38. Derivatives prepared to alter the physicochemical properties produced inhibitors with IC(50)'s in human whole blood as low as 83 nM.

Stereoselective preparation of (Z)-2-(trialkylsilyloxy)-2-alkenals by retrocycloaddition reactions of 4H-4-Alkyl-5-(trialkylsilyloxy)-1,3-dioxins. Useful reactants for Lewis acid catalyzed [4 + 3] cyclizations.

[reaction: see text]. Retrocycloadditions of 4H-4-alkyl-5-(trialkylsilyloxy)-1,3-dioxins proceed smoothly in refluxing toluene to afford (Z)-2-(trialkylsilyloxy)-2-alkenals with complete stereoselectivity. These enals undergo Sasaki-type [4 + 3] cyclizations with dienes in the presence of Lewis acids, in many instances with excellent regio- and/or stereoselectivity.

Total synthesis of the sesquiterpene (+/-)-illudin C via an intramolecular nitrile oxide cycloaddition.

[reaction: see text] A convergent total synthesis of illudin C is described. The tricyclic ring system of the natural product was quickly assembled from cyclopropane and cyclopentene precursors via a novel oxime dianion coupling reaction and a subsequent intramolecular nitrile oxide-olefin cycloaddition.