A series of N-heterocyclic carbene transition metal (molybdenum, tungsten and ruthenium) carbonyl complexes derived from 1-[2-(pyrazol-1-yl)phenyl]-imidazole have been synthesized and characterized by physico-chemical and spectroscopic methods, and the structures of five complexes have been confirmed by X-ray crystal structure analyses. The azaaryl-functionalized N-heterocyclic carbenes act as chelating N,C-bidentate ligands in these five complexes. Preliminary catalytic tests of these NHC-molybdenum (tungsten) carbonyl complexes in the oxidation of styrene have been carried out, showing that benzaldehyde was the main oxidation product when hydrogen peroxide was used as the oxidant, while 2,5-diphenyl-1,4-dioxane was obtained as the exclusive product in the oxidation by tert-butyl hydroperoxide.

A very efficient two-step synthesis was developed to prepare the key intermediate in Corey's Tamiflu synthesis. DBU (1,.0] undec-7-ene) was used as a multifunctional catalyst for a series of reactions in a one pot procedure. The new synthesis was featured by the good availability of the starting material and the ease of the synthetic steps. This method might be practical for large scale preparations.

Efficient Preparation of the Key Intermediate in Corey's Tamiflu Synthesis. -The simple two-step synthesis of the compounds (VI) which starts from easily available material and may be practical for large-scale preparations affords the title intermediate (VIc). A more facile synthesis of (VI) is also investigated but is less effective for (VIc).-(HONG*, Z.; CUI, Q.; PENG, J.; HU, H.; CHEN, Z.; Chin.