Base-Promoted, Selective Aliphatic Carbon−Carbon Bond Cleavage of Ethers by Rhodium(III) Porphyrin Complexes
作者:Tsz Ho Lai、Kin Shing Chan
DOI:10.1021/om900270v
日期:2009.12.28
Base-promoted, selective aliphatic carbon(α)−carbon(β) bond activation (CCA) of ethers by (5,10,15,20-tetramesitylporphyrinato)rhodium(III) iodide was achieved.
Room-Temperature Selective Aliphatic Carbon–Carbon Bond Activation and Functionalization of Ethers by Rhodium(II) Porphyrin
作者:Siu Yin Lee、Tsz Ho Lai、Kwong Shing Choi、Kin Shing Chan
DOI:10.1021/om200280w
日期:2011.7.25
Selective aliphatic carbon(alpha)-carbon(beta) bond activation of ethers by (5,10,15,20-tetramesitylporphyrinato)rhodium (II) (Rh(tmp) (1)) was achieved at room temperature to yield corresponding rhodium porphyrin alkyls and the functionalized esters. Rh(tmp)OH was the proposed intermediate responsible for cleaving the C(alpha)-C(beta) bond. The reaction is general for both straight- and branch-chain ethers.
Mechanistic Studies of Si−CN and C−NC Bond Activation of Silylnitriles and Alkyl Isonitriles by Rhodium Porphyrin Radical: Novel Cyanide Transfer
作者:Lirong Zhang、Chun Wah Fung、Kin Shing Chan
DOI:10.1021/om0605276
日期:2006.10.1
The Si-CN and C-NC bonds of silylnitriles and alkyl isonitriles were activated by (tetramesitylporphyrinato) rhodium(II), Rh(tmp), to give rhodium porphyrin silyls or alkyls and rhodium porphyrin cyanide, respectively. Pyridine and triphenylphosphine promoted the rates and yields of the reactions with silylnitriles, but inhibited the rates and yields of the reactions with isonitriles. The reaction of Rh( tmp) with Me3SiCN exhibited second-order kinetics (rate = k(obs)[Rh(tmp)][Me3SiCN]) at a sufficiently high concentration of pyridine. The reaction with BuNC showed fourth-order kinetics, second-order in each of the reactants; rate = k(obs)[Rh(tmp)](2)[BuNC](2). A novel cyanide transfer rate-determining step was proposed to account for the reaction mechanism.
Facile Aerobic Alkylation of Rhodium Porphyrins with Alkyl Halides
作者:Wu Yang、Huiping Zuo、Wai Yan Lai、Shiyu Feng、Yat Sing Pang、Kai En Hung、Chu Yi Yu、Yin Fan Lau、Ho Yin Tsoi、Kin Shing Chan
DOI:10.1021/acs.organomet.5b00488
日期:2015.8.24
Ligand-Enhanced Aliphatic Carbon−Carbon Bond Activation of Nitroxides by Rhodium(II) Porphyrin
作者:Kin Shing Chan、Xin Zhu Li、Siu Yin Lee
DOI:10.1021/om1000869
日期:2010.7.12
Rh(tmp) underwent Ph3P-enhanced aliphatic carbon carbon bond activation with various nitroxides. (Ph3P)Rh(tmp), rapidly formed from Rh(tmp) and Ph3P, enhanced the rate, selectivity, and yield in comparison to Rh(tmp). From kinetic studies, the rate of reaction showed a first-order dependence on both Rh(tmp) and TEMPO (TEMPO = 2,2,6,6-tetramethylpiperidine-1-oxyl) and saturation kinetics on Ph3P. The rate enhancement of (Ph3P)Rh(tmp) over Rh(tmp) was estimated to be about 11 at 70 degrees C.