Hulme, C., Liang, M. a., Kumar, N. V., Krolikowski, P. H., Allen, A. C., & Labaudiniere, R. (2000). Novel applications of resin bound α-amino acids for the synthesis of benzodiazepines (via Wang resin) and ketopiperazines (via hydroxymethyl resin). Tetrahedron Letters, 41(10), 1509-1514.
Abstract:
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. 10000 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. (C) 2000 Elsevier Science Ltd.
Ayaz, M., Xu, Z., & Hulme, C. (2014). Novel succinct routes to Quinoxalines and 2-Benzimidazolylquinoxalines via the Ugi reaction. Tetrahedron letters, 55(23), 3406-3409.
This communication reveals a unique, user-friendly, concise two-step, one-pot protocol for the synthesis of highly substituted quinoxalines. Conducting the Ugi reaction with appropriately functionalized classical Ugi reagents with subsequent acid treatment of the Ugi adduct affords collections of diversified quinoxalines in good to excellent yields. The methodology exploits what may be viewed as a 'convertible carboxylic acid', which in addition may be captured in an intramolecular sense to generate structurally complex 2-benzimidazolylquinoxalines in a mere two steps.
Hulme, C., & Maggiora, G. M. (2008). Molecular diversity: from small to large, emerging to enabling. Current Opinion in Chemical Biology, 12(3), 257-259.
Hulme, C., Foley, C., & Shaw, A. (2016). Two step route to diverse N-functionalized peptidomimetic-like Isatins through an oxidation/intramolecular oxidative-amidation cascade of Ugi-azide and Ugi-3CR reaction products.. Organic Letters, 18, 4904-4907.
Hulme, C., Morrissette, M. M., Volz, F. A., & Burns, C. J. (1998). The solution phase synthesis of diketopiperazine libraries via the Ugi reaction: Novel application of Armstrong's convertible isonitrile.. Tetrahedron Letters, 39(10), 1113-1116.
Abstract:
This communication describes the generation of high-yielding solution phase diketopiperazine libraries via a '3-step, 1-pot' procedure, employing the Ugi multi-component reaction (MCR), followed by BOC deprotection and cyclization to diketopiperazine (DKP). Exploitation of Armstrong's convertible isonitrile in the Ugi reaction utilising an 'internal nucleophile' approach for diketopiperazine formation is presented.