30764-40-0Relevant articles and documents
Preparation of organocobalt(iii) complexesviaO2activation
Kongsted, Jacob,M?ller, Mads Sondrup,McKenzie, Christine J.
supporting information, p. 4819 - 4829 (2021/04/22)
The coupling of selective C-H activation with O2activation is an important goal for organic synthesis. New experimental and computational results, along with the results from experimental work accumulated over many decades, now unequivocally link O2activation with C-H activation by the classic Co(salen) complexes. A common holistic mechanistic framework can rationalise the formation of ostensibly diverse peroxo, superoxo, organo and alkoxide complexes of CoIII(salen). DFT calculations show that cobalt(iii)superoxo, dicobalt(iii)peroxo and cobalt(iii)hydroperoxo complexes are all viable intermediates as participants in hydrogen atom transfer reactions, whereas a Co(iv)oxo intermediate is unlikely. The reaction conditions will determine the pathway followed and all pathways are initiated through the initial formation of a superoxo complex, CoIII(salen)(O2?)(MeOH) (EPR:g= 2.025,A= 19 G). Organo and alkoxide ligands are derived from solvent media and the trends in reactivity reveal that combination of the pKaand BDE of the C-H of the respective solvent substrates are important. These data explain why landmark, structurally characterized, μ2-?1,?2-peroxide and ?1-superoxide Co(salen)-O2adducts were predominantly isolated from solvents with high C-H pKavalues (DMSO, DMF, DMA).
Direct Acyl Radical Addition to 2 H-Indazoles Using Ag-Catalyzed Decarboxylative Cross-Coupling of α-Keto Acids
Bogonda, Ganganna,Kim, Hun Young,Oh, Kyungsoo
supporting information, p. 2711 - 2715 (2018/05/22)
A direct acyl radical addition to 2H-indazoles has been achieved for the first time, where the less-aromatic quinonoid 2H-indazoles readily accepted radical species to the C-3 position. Motivated by the lack of direct acylation strategy for 2H-indazoles, the current method utilizes the radical acceptability of 2H-indazoles, discovering an ambient temperature reaction to provide facile access to a diverse array of 3-acyl-2H-indazoles with three points of structural diversification in 25%-83% yields.
