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Cooperative Lewis Acid‐1,2,3‐Triazolium‐Aryloxide Catalysis: Pyrazolone Addition to Nitroolefins as Entry to Diaminoamides.
- Source :
- Angewandte Chemie International Edition; Sep2023, Vol. 62 Issue 36, p1-12, 12p
- Publication Year :
- 2023
-
Abstract
- Pyrazolones represent an important structural motif in active pharmaceutical ingredients. Their asymmetric synthesis is thus widely studied. Still, a generally highly enantio‐ and diastereoselective 1,4‐addition to nitroolefins providing products with adjacent stereocenters is elusive. In this article, a new polyfunctional CuII‐1,2,3‐triazolium‐aryloxide catalyst is presented which enables this reaction type with high stereocontrol. DFT studies revealed that the triazolium stabilizes the transition state by hydrogen bonding between C(5)−H and the nitroolefin and verify a cooperative mode of activation. Moreover, they show that the catalyst adopts a rigid chiral cage/pore structure by intramolecular hydrogen bonding, by which stereocontrol is achieved. Control catalyst systems confirm the crucial role of the triazolium, aryloxide and CuII, requiring a sophisticated structural orchestration for high efficiency. The addition products were used to form pyrazolidinones by chemoselective C=N reduction. These heterocycles are shown to be valuable precursors toward β,γ'‐diaminoamides by chemoselective nitro and N−N bond reductions. Morphological profiling using the Cell painting assay identified biological activities for the pyrazolidinones and suggest modulation of DNA synthesis as a potential mode of action. One product showed biological similarity to Camptothecin, a lead structure for cancer therapy. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 14337851
- Volume :
- 62
- Issue :
- 36
- Database :
- Complementary Index
- Journal :
- Angewandte Chemie International Edition
- Publication Type :
- Academic Journal
- Accession number :
- 171105772
- Full Text :
- https://doi.org/10.1002/anie.202307317