930574-01-9

Upstream product

• 352-32-9 p-fluorotoluene 
• 205259-72-9 rhodium(III) tetrakis(4-tolyl)porphyrin chloride 
• 103533-61-5 (5,10,15,20-tetrakis-4-tolylporphyrinato)(methyl)rhodium(III) 
• 108-88-3 toluene 
• 459-56-3 4-fluorobenzylic alcohol 

Relevant academic research and scientific papers

Alkylation of Rhodium Porphyrin Complexes with Primary Alcohols under Basic Conditions

Primary alcohols were successfully 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.

Base-promoted selective activation of benzylic carbon-hydrogen bonds of toluenes with rhodium(III) porphyrin chloride: Synthetic scopes and mechanism

Toluenes underwent base-promoted selective benzylic carbon-hydrogen bond activation (CHA) with rhodium porphyrin chlorides (Rh(por)Cl). In the absence of nucleophilic base, both aryl and benzylic rhodium porphyrins were formed. In the presence of nucleophilic base, the selectivity, rates and functional group compatibilities of benzylic activation reactions were enhanced. K 2CO3 was found to be the optimal base to achieve the best yields. Ortho-, meta- and para-substituted toluenes in the presence of K 2CO3 yielded the corresponding rhodium porphyrin benzyls in high yields both in solvent-free conditions and in benzene solvent. Mechanistically, in the absence of nucleophilic base, a cationic rhodium(III) porphyrin species together with some rhodium(II) porphyrin are the most likely intermediates to account both the aryl and benzylic CHA. In the presence of a base, Rh(por)OH is generated by ligand substitution with Rh(por)Cl and rapidly undergoes reduction to give rhodium(II) porphyin dimer and H2O 2. The key rhodium porphyrin intermediates for benzylic CHA were found to be rhodium(II) porphyrin dimer and hydrides as observed by 1H NMR spectroscopy, which underwent parallel benzylic CHA reactions with the rhodium(II) porphyrin dimer being the more reactive intermediate.

Selective activation of benzylic carbon-hydrogen bonds of toluenes with rhodium(III) porphyrin methyl: Scope and mechanism

Toluenes underwent selective benzylic carbon-hydrogen bond activation (BnCHA) with rhodium(III) porphyrin methyl. The ortho-, meta-, and para-substituted toluenes yielded the corresponding rhodium porphyrin benzyls in high yields in solvent-free conditions as well as in benzene solvent. Mechanistically, Rh(ttp)Me likely undergoes a σ-bond metathesis pathway. The small value of the kinetic isotope effect (2.7) indicates a bent transition state. The negative slope (-1.1) of the linear free energy relationship Hammett plot supports that the benzylic carbon builds up a positive charge in the transition state.

Base-promoted selective activation of benzylic carbon-hydrogen bonds of toluenes by rhodium(III) porphyrins

Toluenes underwent selective benzylic carbon-hydrogen bond activation with rhodium porphyrin chlorides. Both the rates and functional group compatibility were enhanced in the presence of K2CO3.