874299-70-4Relevant academic research and scientific papers
Mild and selective c(co)c(α) bond cleavage of ketones by rhodium(iii) porphyrins: Scope and mechanism
Fung, Hong Sang,Li, Bao Zhu,Chan, Kin Shing
, p. 570 - 579 (2012/04/10)
Rhodium(III) porphyrins were found to undergo selective C(CO)C(α) bond activation (CCA) of ketones promoted by water at temperatures as low as 50 °C. The acyl group of the ketone was transferred to the rhodium center, and the alkyl fragment was oxidized to a carbonyl moiety accordingly. The hydroxyl group of water is transferred to the rhodium porphyrin through hydrolysis of the kinetic α- carbonhydrogen bond activation (α-CHA) product to give RhIII(ttp)OH (ttp = 5,10,15,20-tetratolylporphyrinato dianion), which subsequently cleaves the C(CO)C(α) bond of ketone.
Syntheses of acyl rhodium porphyrins by aldehydic carbon-hydrogen bond activation with Rh(III) porphyrin chloride and methyl
Chan, Kin Shing,Lau, Cheuk Man
, p. 260 - 265 (2008/10/09)
Rhodium(III) porphyrin chloride reacted with aryl aldehydes in solvent-free conditions to give acyl rhodium porphyrins. Selective aldehydic without any aromatic carbon-hydrogen bond activation (CHA) was observed. At lower temperature, reduction and side products were found. Alkanals reacted poorly. On the other hand, Rh(III) porphyrin methyl reacted more cleanly with both aryl and alkyl aldehydes. These reactions provided a facile, convenient synthesis of acyl rhodium porphyrins. These activations are unique CHA by high-valent Rh(III) species. Preliminary mechanistic experiments suggested that the rhodium(III) porphyrin chloride initially formed a cationic rhodium(III) porphyrin via chloride dissociation and then underwent oxidative addition or heterolysis to yield the product. On the other hand, rhodium(III) porphyrin methyl underwent either oxidative addition or σ bond metathesis.
