Roberts, S. A., Martinez-Ariza, G., Dietrich, J., & Hulme, C. (2012). 2,4-Diphenyl-6-trifluoromethyl-2,3-dihydro-1H,5H-pyrrolo-[3,4-c]pyrrole-1, 3-dione. Acta Crystallographica Section E: Structure Reports Online, 68(2), o496-o497.
PMID: 22347098;PMCID: PMC3275242;Abstract:
The asymmetric unit of the title compound, C 19H 11F 3N 2O 2, contains two crystallographically unique mol-ecules which differ in the rotation of a phenyl ring and a -CF3 substituent. The dihedral angles involving the pyrrole ring and the attached phenyl ring are 62.82 (8) and 71.54 (7)° in the two molecules. The difference in the rotation of the CF3 groups with respect to the pyrrolo rings to which they are attached is 23.5(1)°. For one mol-ecule, there is a close contact between an H atom and the centroid of the phenyl ring of an adjacent mol-ecule (2.572 Å). A similar contact is lacking in the second mol-ecule. In the crystal, N - H⋯O inter-actions connect adjacent mol-ecules into a chain normal to (01 ). Crystallographically unique mol-ecules alternate along the hydrogen-bonded chains.
Hulme, C., Medda, F., & Martinez-Ariza, G. (2015). A facile and rapid route toward the synthesis of novel imidazo-tetrazolodiazepinones via post-condensation modifications of the Ugi-azide adduct.. Tetrahedron Letters, 56, 5295-5298.
Gunawan, S., & Hulme, C. (2013). Construction of functionalized tricyclic dihydropyrazino-quinazolinedione chemotypes via an Ugi/N-acyliminium ion cyclization cascade. Tetrahedron Letters, 54(33), 4467-4470.
Abstract:
Dihydropyrazino-quinazolinedione chemotypes are complex and structurally challenging structures of biological interest, being found in the marine alkaloids such as brevianamide M-N and fumiquinazolines A-C. Herein we report the synthesis of this tricyclic system in three synthetic operations by means of an Ugi multi-component reaction (MCR) followed by a tandem N-acyliminium ion cyclization-intramolecular nucleophilic addition reaction sequence. Additional structural diversification for further library enrichment was also accomplished via sequential N-alkylation and N-acylation/sulfonation. © 2013 Elsevier Ltd. All rights reserved.
Nixey, T., Tempest, P., & Hulme, C. (2002). Two-step solution-phase synthesis of novel quinoxalinones utilizing a UDC (Ugi/de-Boc/cyclize) strategy. Tetrahedron Letters, 43(9), 1637-1639.
Abstract:
The novel solution-phase synthesis of an array of biologically relevant quinoxalinones in a simple two-step procedure is revealed. Transformations are carried out in excellent yield by condensation of mono-Boc protected ortho-phenylene di-amine, glyoxylic acids and supporting Ugi reagents. Subsequent acid treatment and evaporation affords quinoxalinones in good to excellent yields. © 2002 Elsevier Science Ltd. All rights reserved.
Hulme, C., Peng, J., Morton, G., Salvino, J. M., Herpin, T., & Labaudiniere, R. (1998). Novel safety-catch linker and its application with a Ugi/De- BOC/cyclization (UDC) strategy to access carboxylic acids, 1,4- benzodiazepines, diketopiperazines, ketopiperazines and dihydroquinoxalinones. Tetrahedron Letters, 39(40), 7227-7230.
Abstract:
This communication reveals the synthesis and application of a novel resin bound isonitrile. The resin is an example of a novel safety-catch linker which upon BOC-activation can be resin cleaved with a variety of nucleophiles. Use of this polymer supported isonitrile in the Ugi multi- component reaction (MCR), followed by resin clipping and cyclization allows access to diverse arrays of 1,4-benzodiazepine-2,5-diones, diketopiperazines and ketopiperazines respectively. The methoxide safety-catch clipping strategy and subsequent solution phase cyclization offers similar advantages to a traceless linker.