874299-75-9Relevant 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
experimental part, 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.
Activation of aldehydic carbon-hydrogen bonds under aerobic conditions by masked rhodium(III) porphyrin cation
Chan, Kin Shing,Lau, Cheuk Man,Yeung, Siu Kwan,Lai, Tsz Ho
, p. 1981 - 1985 (2008/10/09)
RhIII(ttp)CH2CH2OH activated the aldehydic carbon-hydrogen bonds of functionalized aryl and enolizable aldehydes to give high yields of Rh(ttp)COR at 50 °C under both anaerobic and aerobic conditions. The Rh(ttp)(C2H4)OH intermediate was proposed to form via β-hydroxy elimination. The reactions exhibited rate and yield enhancement upon the addition of Ph3P, suggesting ligand-promoted β-elimination. The nonlinear free energy relationship of the Hammett plot suggested a multistepwise reaction with the rate-determining step (binding or activation) dependent on the electronic effect of para substituents of aryl aldehydes.
