Nonradical Trapping Pathway for Reactions of Nitroxides with Rhodium Porphyrin Alkyls Bearing β-Hydrogens and Subsequent Carbon−Carbon Bond Activation
摘要:
A novel nitroxide-induced hydrogen atom abstraction and beta-elimination of rhodium porphyrin alkyls has been observed. Subsequent carbon-carbon bond activation of methyl-substituted nitroxides by the rhodium(II) porphyrin radical yielded rhodium porphyrin methyl complexes.
1,2-Rearrangements of β-Nitrogen-Substituted (Porphyrinato)rhodium(III) Ethyls
摘要:
(Porphyrinato)rhodium(III) ethyls containing beta-nitrogen substituents have been showed to undergo clean, thermal 1,2-rearrangements into the alpha-nitrogen-substituted rhodium ethyls. The rates and the equilibrium positions were found to be dependent on the electronic nature of the N substituents. Complexes 1a-3a were characterized by X-ray crystallography.
Alkylation of Rhodium Porphyrin Complexes with Primary Alcohols under Basic Conditions
作者:Yongjun Bian、Chun Meng Tam、Ching Tat To、Xingyu Qu、Kin Shing Chan
DOI:10.1021/acs.organomet.9b00454
日期:2019.10.14
utilized as the alkylating reagents to conveniently access rhodium porphyrin alkyl complexes in up to 91% yields under basic conditions. Mechanistic investigations suggest two possible pathways for the C–O bond cleavage: (1) nucleophilic substitution with rhodium(I) porphyrin anion and (2) a borrowing hydrogen pathway via rhodium(III) porphyrin hydride.
Nitroxide-induced beta-hydrogen atom abstraction and beta-elimination of rhodium porphyrin alkyls have been observed. Rhodium(II) porphyrin radical were proposed intermediates to form first and subsequently reacted via aliphatic carbon–carbon bond activation with alkyl substituted nitroxides to yield rhodium porphyrin alkyl complexes.