Novel applications of resin bound α-amino acids for the synthesis of benzodiazepines (via Wang resin) and ketopiperazines (via hydroxymethyl resin)

This communication reveals a novel application of resin bound α-amino acids coupled with the UDC (Ugi/DeBOC/cyclize) strategy. Reaction with either N-BOC-α-amino aldehydes or N-BOC anthranilic acids and subsequent acid treatment allows the preparation of highly pure and diverse arrays (approx. 10 000 in size) of 1,4-benzodiazepines (Wang resin) and ketopiperazines (hydroxymethyl resin), respectively. Notable for the benzodiazepine series of compounds are the five potential points of diversity available from this two-step protocol.