Preparation of New Microgel Polymers and Their Application as Supports in Organic Synthesis
作者:Carsten Spanka、Bruce Clapham、Kim D. Janda
DOI:10.1021/jo016362m
日期:2002.5.1
A series of soluble microgel polymers have been synthesized using solution-phase polymerization reactions. In a systematic manner, several variables such as monomer concentration, cross-linker content, reaction solvent and reaction time were examined, and this provided an optimal polymer with both solubility and precipitation characteristics suitable for synthetic applications. Thus, a chemically functionalized microgel polymer was synthesized, and the utility of this polymer in the synthesis of a small array of oxazole compounds has been demonstrated. The advantage of the microgel polymers produced was that they exhibited solution viscosities lower than those of conventional linear polymers even at higher concentrations, and this was found to be beneficial for their precipitation properties. Compounds prepared using the described microgel polymer supports were obtained in similar yields and purity when compared with insoluble resins, and more importantly, the soluble polymer bound intermediates could be analyzed at each step using standard NMR techniques.
Electrochemically promoted synthesis of polysubstituted oxazoles from β-diketone derivatives and benzylamines under mild conditions
An efficient electrochemical synthesis of poly-substituted oxazoles from readily available β-diketone derivatives and benzylamines is described. This electrochemical procedure does not need hazardous oxidants and transition metal catalysts as well as molecular I2 additives. Compared with the traditional thermo-chemical method, the present electrochemical method is greener and more efficient.