Glyoxylic acid and MP-glyoxylate: efficient formaldehyde equivalents in the 3-CC of 2-aminoazines, aldehydes, and isonitriles.

[reaction: see text] Glyoxylic acid, either in solution or immobilized on MP-carbonate (MP-glyoxylate), participates in an uncatalyzed 3-CC with 2-aminoazines and isonitriles to afford novel 2-unsubstituted-3-amino-imidazoheterocycles. MP-glyoxylate serves as a particularly efficient and experimentally convenient formaldehyde equivalent and readily liberates products through decarboxylation/self-release from the resin. These examples furthermore constitute the first application in which MP-CO3 serves as a solid support for transformations involving carboxylic acids.