7721-49-5

Upstream product

• 109-97-7 pyrrole 
• 463-82-1 2,2-dimethylpropane 

Downstream Products

• 156245-57-7 4-tert-butylpyrrole-2-carboxaldehyde 
• 97188-41-5 5-acetyl-3-tert-butyl-1-(phenylsulfonyl)pyrrole 
• 97188-42-6 4-acetyl-3-tert-butyl-1-(phenylsulfonyl)pyrrole 
• 381665-66-3 3-(tert-butyl)pyrrolidine 

Relevant academic research and scientific papers

First Example of Predominant β-Orientation in Electrophilic Substitution of Pyrrole

The isomeric distribution of the neutral products from the gas-phase electrophilic attack of 3He3H+, CH3FCH3+, and t-C4H9+ ions on pyrrole provides the first experimental evidence for predominant β-orientation in electrophilic substitution of pyrrole .

Gas-phase Heteroaromatic Substitution. Part 4. Electrophilic Attack of t-Butyl Cation on Pyrrole, N-Methylpyrrole, Furan, and Thiophene

t-Butyl cation, obtained in the gas state from the γ-radiolysis of neopentane has been allowed to react with pyrrole (1), N-methylpyrrole (2), furan (3), and thiophene (4).Experiments have been carried out in the pressure range 50-760 Torr and in the presence of variable concentrations of a gaseous base (NMe3).The reactivity of simple heteroaromatic compounds relative to toluene in competition experiments is found to depend markedly upon the composition of the gaseous reaction environment.The apparent kS/kT ratios decrease slightly with increasing pressure.At atmospheric pressure, these ratios increase with the NMe3 concentration levelling off to a value of 1.0 (1), 2.2 (2), 2.6 (3), and 0.6 (4), at the highest base concentration (PNMe3=10 Torr).Under the same conditions, predominant β substitution occurs in the pyrroles , whereas α-attack is favoured in the case of furan (β:α=9:91) and thiophene (β:α=20:80).The gaseous elecrophile appears rather unselective between the n- and the ?-type centres of furan (O:ring=50:50) and thiophene (S:ring=40:60), while it displays no or very limited substitution on the heteroatom of pyrroles.A mechanism based upon reversible addition of the t-butyl cation to the heteroaromatic nucleus, involving premilinary formation of an electrostatic adduct, is used to account for the formation of the t-butylated products and their isomeric composition.It is concluded that the gas-phase t-butyl alkylation of simple five-membered heteroaromatic compounds is regulated by electrostatic interactions established within the encounter pair.A close correspondence exists between this rationalization of the present gas-phase results and recent theoretical and experimental evidence concerning related alkylation processes.