Polymer-bound isocyanide

Samanta SK, Kylanlahti 1, Yli-Kauhaluoma J (2005) Microwave-assisted synthesis of imidazoles reaction of p-toluenesulfonylmethyl isocyanide and polymer-bound imines. Bioorg Med Chem Lett 15 3717-3719... 

Multicomponent reactions have been described for several syntheses of imidazoles. Highly efficient methods for the syntheses of spiroimidazolinones via microwave-assisted three-component one-pot sequential reactions or one-pot domino reactions have been described <06JOC3137>. Multicomponent reactions between 2-aminopyrimidine, aldehydes and isonitriles afforded imidazo[l,2-a]pyrimidines <06TL947>. Two novel one-step microwave mediated syntheses of arrays of 3-iminoaryl-imidazo[l,2-a]pyridines and imidazo[l,2-a]pyridyn-3-ylamino-2-acetonitriles were synthesized by multicomponent reactions under microwave condition in methanol by simply mixing a-aminopyridines, aldehydes, and trimethylsilylcyanide catalyzed by polymer-bound scandium triflate <06TL2989>. 3-Aminoimidazo[l,2-a]pyridines have been synthesized via the multicomponent reaction of aldehydes, isocyanides and 2-aminopyridines in the presence of the ionic liquid l-butyl-3-methylimidazolium bromide [bmim]Br<06TL3031>. 

One example of a library synthesized via MW-assisted soHd-phase MCRs is that of Hoel and Nielson [13] (Scheme 2.3-9). The authors performed Ugi-4CC (four component condensation) reactions in a monomodal MW reactor between polymer (TentaGel)-bound amines and various aldehydes, carboxylic acids, and isocyanides to yield a mini library of 18a-acylaminoamides in just 15 minutes per compound. The reaction time was reduced by a factor of three. The yields were variable, but the authors reported highly pure products (>95%). 

---