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The tert-butyl cation is a relatively stable carbenium ion. [1] A carbenium ion is a positive ion with the structure RR′R″C +, that is, a chemical species with carbon atom having three covalent bonds, and it bears a +1 formal charge. Carbenium ions are a major subset of carbocations, which is a general term for diamagnetic carbon-based cations.
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 effect of the tert-butyl group on the progress of a chemical reaction is called the Thorpe–Ingold effect illustrated in the Diels-Alder reaction below. Compared to a hydrogen substituent, the tert-butyl substituent accelerates the reaction rate by a factor of 240. [2] tert-Butyl effect. The tert-butyl effect is an example of steric hindrance.
An example of a reaction taking place with an S N 1 reaction mechanism is the hydrolysis of tert-butyl bromide forming tert-butanol: This S N 1 reaction takes place in three steps: Formation of a tert-butyl carbocation by separation of a leaving group (a bromide anion) from the carbon atom: this step is slow. [5] Recombination of carbocation ...
(1984) "Gas-phase reactions of free phenylium cations with C3H6 hydrocarbons". [19] (1985) "Intramolecular selectivity of the alkylation of substituted anilines by gaseous cations". [20] (1986) "Temperature dependence of the substrate and positional selectivity of the aromatic substitution by gaseous tert-butyl cation". [21]
There are also a large number of branched or ring alkanes that have specific names, e.g., tert-butyl, bornyl, cyclohexyl, etc. There are several functional groups that contain an alkene such as vinyl group, allyl group, or acrylic group. Hydrocarbons may form charged structures: positively charged carbocations or negative carbanions.
It is able to protonate butane to form tert-butyl cation at room temperature and is the only known acid to protonate carbon dioxide to give the bridged cation, [H(CO 2) 2] +, making it possibly the strongest known acid. In particular, CO 2 does not undergo observable protonation when treated with the mixed superacids HF-SbF 5 or HSO 3 F-SbF 5 ...
tert-Butyloxycarbonyl protecting group. The tert-butyloxycarbonyl protecting group or tert-butoxycarbonyl protecting group [1] (BOC group) is an acid-labile protecting group used in organic synthesis. The BOC group can be added to amines under aqueous conditions using di-tert-butyl dicarbonate in the presence of a base such as sodium hydroxide: