4 R-40 + 3 R-134a + [Al.sub.solid] = 3 R133a + Al[F.sub.4.sup.-] + 4 C[H.sub.3] + carbocation
It turns out that particular meso-PCP+ structures involving primary carbocations
are what slow down the chain-branching steps.
This result indicates that the reactivity of the carbocationic species generated during the polymerization process, which includes the initiating carbocations
and chain propagating carbocations
, were reactive enough to polymerize the vinylether groups of the VESFA, but not so reactive that they add to double bonds of the fatty acid portion of VESFA.
These chemical reactions would involve the formation of transient carbocation
Experimental and theoretical evaluation of energetics for nucleophilic solvent participation in the solvolysis of tertiary alkyl chlorides on the basis of gas phase bridgehead carbocation
A key aspect of this synthesis was the TMSOTf-mediated epoxide opening that proceeds trough a carbocation
mechanism leading to the possibility of methyl migration and hydride shift side reactions.
This, and our detection of rearranged products (equation 2) suggest that the mechanism could involve either 1) elimination followed by addition of water and then another elimination, 2) elimination followed by protonation to form a different carbocation
which then eliminates, or 3) a mechanism that is more "E2-lik e" for the stereoisomer which readily exists in an anti-periplanar conformation while the other stereoisomer reacts by a more "E1-like" mechanism.
They believed this was possible because carbon, a close relative on the periodic table, can form a "carbocation
," which also has three bonds and a positive charge.
Considering that B1 is a secondary carbocation
, its rearrangement to B2 (a tertiary carbocation
) by means of a 1,2-alkyl shift is driven by the charge stabilization .
A reaction mechanism during the preparation was proposed, and the electron effect on the stabilization of the carbocation
According to the reaction mechanism discussed previously, the solvolytic splitting of [alpha]-aryl ether in lignin resulted in the formation of a benzylic carbocation
, which would react with different alcohols in an acidic medium.
The nitrogen stabilized carbocation
is the conjugate acid of the imine and transfer of the hydrogen atom, attached to the nitrogen, to water yields the imine.