1383675-80-6Relevant academic research and scientific papers
Development of Structurally Diverse N-Heterocyclic Carbene Ligands via Palladium-Copper-Catalyzed Decarboxylative Arylation of Pyrazolo[1,5-a]pyridine-3-carboxylic Acid
Alam, Khyarul,Kim, Seong Min,Kim, Do Joong,Park, Jin Kyoon
, p. 2661 - 2670 (2016)
A series of fused non-classical normal N-heterocyclic carbenes, Pyrpy-NHC precursors derived from pyrazolo[1,5-a]pyridines, has been prepared using palladium-copper-catalyzed decarboxylative arylation of pyrazolo[1,5-a]pyridine-3-carboxylic acid. Air-stable palladium and rhodium complexes of these ligands have been synthesized via mild transmetallation of Ag-Pyrpy-NHC. The structural properties of Rh(Pyrpy-NHC)(COD)Cl complexes were determined via X-ray analysis. The measurement of the CO stretching frequencies of dicarbonyl Rh-Pyrpy-NHC complexes revealed that the electron donating strength of Pyrpy-NHC could be tuned by varying the substituents of the aryl group. A catalytic study of the Pd-Pyrpy-NHC complexes revealed promising activity in the Suzuki–Miyaura reaction under ambient atmospheric conditions. (Figure presented.).
C-H Activation/Metalation Approaches for the Synthesis of Indolizine Derivatives
Bertallo, Camila R. d. S.,Arroio, Thais R.,Toledo, M?nica F. Z. J.,Sadler, Scott A.,Vessecchi, Ricardo,Steel, Patrick G.,Clososki, Giuliano C.
, p. 5205 - 5213 (2019/07/04)
The C–H borylation of indolizines has not previously been reported. In this communication, we describe our preliminary efforts to apply this chemistry to this scaffold and contrast this approach to directed metalation. Through these methodologies, it was possible obtain a library of substituted indolizines functionalized on both the pyridinic and pyrrole rings.
Optimized scale up of 3-pyrimidinylpyrazolo[1,5-a]pyridine via Suzuki coupling; A general method of accessing a range of 3-(hetero)arylpyrazolo[1,5-a] pyridines
Bethel, Paul A.,Campbell, Andrew D.,Goldberg, Frederick W.,Kemmitt, Paul D.,Lamont, Gillian M.,Suleman, Abid
, p. 5434 - 5444 (2012/09/08)
We have developed an improved synthesis of 3-(hetero)aryl pyrazolo[1,5-a]pyridines (such as 3-(2,5-dichloropyrimidin-4-yl)pyrazolo[1,5-a] pyridine (8)) via an optimized synthesis and Suzuki coupling of 3-pyrazolo[1,5-a]pyridine boronic ester 10. These conditions are applicable to both high throughput chemistry and large scale synthesis of these medicinally important compounds. The scope of this chemistry has been further extended to include the synthesis and coupling of a novel boronic ester, 3-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-6,7-dihydro-5H-pyrazolo[5,1-b] [1,3]oxazine (43).
