Chapter 2 Recent advances in the reaction of metalated aromatic heterocycles with carbonyl compounds and their imino derivatives

Novel Use of Imidazolium Ylides in an Efficient Synthesis of 2-Substituted Imidazoles

“…Imidazoles are important as heterocyclic components of many drugs and biologically active molecules. , Consequently, new, efficient methodology for the preparation of imidazole derivatives would provide a valuable tool to synthetic organic chemists. Relative to functionalizing imidazole at the 2-position, 2-lithioimidazoles are generated with strong bases (e.g., BuLi) at low temperatures and under anhydrous conditions and then captured by electrophiles. , Imidazoles can be directly acylated at the 2-position or thermally condensed with aldehydes or isocyanates, although the yields in the aldehyde reaction can be highly variable and substrate-dependent . 2-Substituted imidazoles are also prepared by reacting 2-trimethylsilyl-1-alkylimidazoles with aldehydes, typically in good yields …”