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4277171 
Journal Article 
The strongest Brønsted acid: protonation of alkanes by H(CHB(11)F(11)) at room temperature 
Nava, M; Stoyanova, IV; Cummings, S; Stoyanov, ES; Reed, CA 
2014 
Yes 
Angewandte Chemie (International Edition)
ISSN: 1433-7851
EISSN: 1521-3773 
Angewandte Chemie 
53 
4 
1131-1134 
English 
24339386 
WOS:000329879500041 
What is the strongest acid? Can a simple Brønsted acid be prepared that can protonate an alkane at room temperature? Can that acid be free of the complicating effects of added Lewis acids that are typical of common, difficult-to-handle superacid mixtures? The carborane superacid H(CHB11 F11 ) is that acid. It is an extremely moisture-sensitive solid, prepared by treatment of anhydrous HCl with [Et3 SiHSiEt3 ][CHB11 F11 ]. It adds H2 O to form [H3 O][CHB11 F11 ] and benzene to form the benzenium ion salt [C6 H7 ][CHB11 F11 ]. It reacts with butane to form a crystalline tBu(+) salt and with n-hexane to form an isolable hexyl carbocation salt. Carbocations, which are thus no longer transient intermediates, react with NaH either by hydride addition to re-form an alkane or by deprotonation to form an alkene and H2 . By protonating alkanes at room temperature, the reactivity of H(CHB11 F11 ) opens up new opportunities for the easier study of acid-catalyzed hydrocarbon reforming. 
Brønsted acids; carbocations; carboranes; hydrocarbons