The tert-butyl cation is a relatively stable carbenium ion. [1] A carbocation is an ion with a positively charged carbon atom. Among the simplest examples are the methenium CH + 3, methanium CH + 5, acylium ions RCO +, and vinyl C 2 H + 3 cations. [2] Until the early 1970s, carbocations were called carbonium ions. [3]

The tert-butyl cation, also known as the tertiary butyl cation, is a carbocation with the chemical formula (CH3)3C+. It is a highly stable and important intermediate in many organic reactions, particularly those involving the rearrangement or fragmentation of tertiary alkyl groups.

Hyperconjugation is due to the interaction of the electrons in σ bond (C-H or C-C) with adjacent empty or partly filled non-bonding p-orbital, antibonding π orbital or filled π orbital. This result in extended molecular orbital and increases the stability of the system.

Briefly, the released t-butyl carbocation is subsequently deprotonated by the anionic TFA, resulting in the formation of 2-methyl-propene. This regenerates the protonated TFA that is needed to continue the reaction, and thus the TFA is catalytic (i.e. not consumed in the reaction). The reaction is, in principle, catalytic in TFA.

2011年3月11日 · From gas phase dissociation energies, the tert butyl carbocation is about 7 kcal/mol more stable (232 kcal/mol) than the benzyl carbocation (238 kcal/mol) but substituent effects can greatly change these numbers.

2023年1月23日 · In 1962, Olah directly observed the tert-butyl carbocation by nuclear magnetic resonance as a stable species on dissolving tert-butyl fluoride in magic acid. The NMR of the norbornyl cation was first reported by Schleyer et al.[15] and it was shown to undergo proton-scrambling over a barrier by Saunders et al.[16]

We now report that tert-butyl and other simple tertiary alkyl cations can be isolated at room temperature and their X-ray structures determined.