Judith A. Olah

Heterogeneous catalysis by solid superacids: 14. Perfluorinated resinsulfonic acid (Nafion-H)-catalyzed friedel-crafts alkylation of toluene and phenol with alkyl chloroformates and oxalates☆

Abstract Perfluorinated resinsulfonic acid (Nafion-H)-catalyzed Friedel-Crafts alkylation of toluene and phenol with alkyl chloroformates and oxalates was studied, in both liquid- and gas-phase reactions. Alkylations gave good yields in clean reactions without the need for any complex decompositions or workup. No acylation side products were formed in the reactions. The question of C- versus O-alkylation is discussed.

Superacidic FSO3H/HF catalyzed butane isomerization [1]

Superacid catalyzed isomerization of butane was studied. Highly efficient isomerization of butane to 2-methylpropane (isobutane) was achieved using fluorosulfuric acid containing up to 5% of hydrogen fluoride acting as a protic co-acid. The isomerization when carried out in excess FSO3H at 21 ° C in a flow system gave ∼70% conversion to 2-methylpropane with generally less than 3% cracking. When 2-methylpropane was isomerized under similar conditions about 12% butane was formed. Attempted isomerization of pentane and hexane with prolonged reaction times in a static system results in predominant protolytic cleavage (cracking).

La regioselettività della nitrazione elettrofila degli α, α, α-trialogenometossibenzeni

Nitration of α, α, α-trihalomethoxybenzenes with nitronium tetrafluoroborate or methyl nitrate/boron trifluoride in nitromethane solution was studied and compared to that of halobenzenes. Predominantpara-substitution is observed with no formation ofmeta isomer. The substrate reactivity compared to benzene (determined in competition experiments) is 0.1 to 0.3.RiassuntoLa nitrazione degli α, α, α-trialogenometossibenzeni con nitronio tetra-fluoroborato o nitrato di metile/trifluoruro di boro in nitrometano è stata studiata e paragonata a quella degli alogenobenzeni. È stata osservata principalmente la para-sostituzione, senza formazione delľisomero meta. La reattività dei substrati relativa alla reattività del benzene è k(C6H5OCX3)/k(C6H6) = 0.1-0.3.La nitrazione degli α, α, α-trialogenometossibenzeni con nitronio tetra-fluoroborato o nitrato di metile/trifluoruro di boro in nitrometano e stata studiata e paragonata a quella degli alogenobenzeni. E stata osservata principalmente la para-sostituzione, senza formazione delľisomero meta. La reattivita dei substrati relativa alla reattivita del benzene e k(C6H5OCX3)/k(C6H6) = 0.1-0.3.

Remarks on the mechanism of ethylene formation from methyl alcohol

Comments on two recent communications are made, while the oxonium ylide mechanism of ethylene formation from methyl alcohol is re-emphasized.