65117-72-8Relevant academic research and scientific papers
Non-Decarboxylative Ruthenium-Catalyzed Rearrangement of 4-Alkylidene-isoxazol-5-ones to Pyrazole- and Isoxazole-4-carboxylic Acids
Loro, Camilla,Molteni, Letizia,Papis, Marta,Lo Presti, Leonardo,Foschi, Francesca,Beccalli, Egle M.,Broggini, Gianluigi
, p. 3092 - 3096 (2022/05/02)
Treatment of 4-(2-hydroaminoalkylidenyl)- and 4-(2-hydroxyalkylidenyl)-substituted isoxazol-5(4H)-ones with catalytic amounts of [RuCl2(p-cymene)]2, without any additive, afforded pyrazole- and isoxazole-4-carboxylic acids, respectively. The presence of an intramolecular H-bond in these substrates was the key to divert the classical mechanism toward a ring-opening non-decarboxylative path that is expected to generate a vinyl Ru-nitrenoid intermediate, the cyclization of which affords the rearranged products. A gram scale protocol demonstrated the synthetic applicability of this transformation.
Divergent Iron-Catalyzed Coupling of O-Acyloximes with Silyl Enol Ethers
Yang, Hai-Bin,Selander, Nicklas
, p. 1779 - 1783 (2017/02/15)
An iron-catalyzed coupling reaction of O-acyloximes and O-benzoyl amidoximes with silyl enol ethers is reported. The protocol provides access to functionalized pyrroles, 1,6-ketonitriles, pyrrolines and imidazolines via carbon-centered radicals generated from an initially formed iminyl radical. The intramolecular cyclization and ring-opening processes of the iminyl radical take place preferentially over reactions that proceed through a 1,3-hydrogen transfer, providing insights into iron-catalyzed reactions with oxime derivatives. The cheap and environmentally friendly iron catalyst, the broad substrate scope and the functional group compatibility make this protocol useful for synthesis of valuable nitrogen-containing products.
Ruthenium-catalyzed pyrrole synthesis via oxidative annulation of enamides and alkynes
Li, Bin,Wang, Nuancheng,Liang, Yujie,Xu, Shansheng,Wang, Baiquan
, p. 136 - 139 (2013/03/28)
An efficient and regioselective ruthenium-catalyzed oxidative annulation of enamides with alkynes via the cleavage of C(sp2)-H/N-H bonds is reported. The reactions can afford N-acetyl substituted or N-unsubstituted pyrroles by altering the reaction conditions slightly.
