Solid‐Phase, Parallel Syntheses by Ugi Multicomponent Condensation

The number and availability of starting compounds determine the structure diversity possible in a multicomponent reaction. For example, in a set of parallel reactions an amino-functionalized resin (P) was treated with 8 aldehydes, 12 carboxylic acids, and 1 isocyanide to provide 88 of the desired α-acyl amino amides [Eq. (a)]. Additional isocyanides not available commercially can be prepared from α-lithiated benzylisonitrile and used without purification. R1, R2 = alkyl, aryl.