CuI-Catalyzed Coupling Reactions of 4-Iodopyrazoles and Alcohols: Application toward Withasomnine and Homologs.

The direct 4-alkoxylation of 4-iodo-1H-pyrazoles with alcohols was achieved by a CuI-catalyzed coupling protocol. The optimal reaction conditions employed excess alcohol and potassium t-butoxide (2 equiv) in the presence of CuI (20 mol%) and 3,4,7,8-tetramethyl-1,10-phenanthroline (20 mol%) at 130 °C for 1 h under microwave irradiation. The present method was efficiently applied to the synthesis of withasomnine and its six- and seven-membered cyclic homologs.

Immobilization of a Boron Center-Functionalized Scorpionate Ligand on Mesoporous Silica Supports for Heterogeneous Tp-Based Catalysts.

To develop novel immobilized metallocomplex catalysts, allyltris(3-trifluoromethylpyrazol-1-yl)borate (allyl-TpCF3) was synthesized. A boron-attached allyl group reacts with thiol to afford the desired mesoporous silica-immobilized TpCF3. Cobalt(II) is an efficient probe for estimating the structures of the immobilized metallocomplexes. The structures of the formed cobalt(II) complexes and their catalytic activity depended on the density of the organic thiol groups and on the state of the remaining sulfur donors on the supports.