Reactivity and kinetic–mechanistic studies of regioselective reactions of rhodium porphyrins with unactivated olefins in water that form β-hydroxyalkyl complexes and conversion to ketones and epoxides
作者:Jiadi Zhang、Bradford B. Wayland、Lin Yun、Shan Li、Xuefeng Fu
DOI:10.1039/b912219b
日期:——
β-hydroxyalkyl rhodium porphyrin complexes which are formed by reactions of terminal alkenes with tetra(p-sulfonatophenyl)porphyrin rhodium(III) complex. The β-hydroxyalkyl rhodium porphyrin complexes in water undergo β-C–H elimination to produce ketones in aqueous pH 9.0 solutions and O–H deprotonation in KOH/DMSO solutions resulting in the rapid and quantitative intramolecular nucleophilicdisplacement to form
Mechanistic comparison of β-H elimination, β-OH elimination, and nucleophilic displacement reactions of β-hydroxy alkyl rhodium porphyrin complexes
作者:Bing Wu、Jiadi Zhang、Lin Yun、Xuefeng Fu
DOI:10.1039/c0dt01146k
日期:——
This article reports on kinetic studies for three alternate pathways, including β-hydrogen elimination, β-hydroxy elimination, and intramolecular nucleophilic displacement reactions, for rhodium porphyrin β-hydroxy alkyl reactions in water and DMSO to form ketone, alkene, and epoxide, respectively. Comparisons of activation parameters for these processes indicate that the β-hydroxy elimination process has the lowest activation enthalpy in water, but the intramolecular nucleophilic displacement pathway predominates in DMSO.