182807-30-3Relevant articles and documents
[4+3] versus [4+2] mechanisms in the dimerization of 2-boryl-1,3-butadienes. A theoretical and experimental study
Carreaux, Francois,Posseme, Francoise,Carboni, Bertrand,Arrieta, Ana,Lecea, Begona,Cossio, Fernando P.
, p. 9153 - 9161 (2002)
The thermal dimerization of 2-boryl-1,3-butadienes and the scope of this reaction to prepare six-membered rings difficult to synthesize by other methodologies have been studied. In addition, the nature of this dimerization has been studied theoretically. It has been found that the reaction coordinate associated with the formation of the cycloadduct of lowest energy has significant [4+3] character. This behavior is caused by the favorable carbon-carbon overlap and the large values of the corresponding resonance integrals. However, beyond the transition structure, the [4+2] pathway becomes the preferred one thus leading to the exclusive formation of the [4+2] cycloadduct. Aside from this effect, donating groups at the boryl moiety favor the [4+2] mechanism.
Catalytic Asymmetric Radical-Polar Crossover Hydroalkoxylation
Discolo, Christopher A.,Touney, Eric E.,Pronin, Sergey V.
, p. 17527 - 17532 (2019)
Asymmetric intramolecular hydrofunctionalization of tertiary allylic alcohols is described. This metal hydride-mediated catalytic radical-polar crossover reaction delivers corresponding epoxides in good to high enantioselectivity and constitutes the first example of asymmetric hydrogen atom transfer-initiated process. A series of modified cobalt salen complexes has proven optimal for achieving good efficiency and asymmetric induction. Experimental data suggest that cationic cobalt complexes may be involved in the enantiodetermining step, where cation-πinteractions in the catalyst contribute to the asymmetric induction.
Intramolecular cyclisations of hydroxylamines derived from limonene: Reverse-Cope or acid-catalysed reactions?
Coogan, Michael P.,Knight, David W.
, p. 6417 - 6420 (2007/10/03)
Intramolecular cyclisations of cis-4-ethenylcyclohexyl hydroxylamines [e.g. 3 derived from limonene] proceed via a reverse-Cope mechanism rather than an acid-catalysed process, as recently reported.
