99058-97-6Relevant articles and documents
Synthesis of 1,3-Cycloalkadienes from Cycloalkenes: Unprecedented Reactivity of Oxoammonium Salts
Nagasawa, Shota,Sasano, Yusuke,Iwabuchi, Yoshiharu
, p. 13189 - 13194 (2016/10/30)
Few methods allow for the direct conversion of cycloalkenes into cycloalkadienes with high chemo- and regioselectivity. Herein, we report a convenient one-pot process for this transformation that involves the unprecedented N-preferential group transfer of N-oxoammonium salts to cycloalkenes, followed by Cope elimination, to afford cycloalkadienes at room temperature and pressure.
Asymmetric Hydroformylation of Heterocyclic Olefins Mediated by Supramolecularly Regulated Rhodium-Bisphosphite Complexes
Rovira, Laura,Vaquero, Mónica,Vidal-Ferran, Anton
supporting information, p. 10397 - 10403 (2015/11/03)
Rhodium complexes derived from conformationally transformable α,ω-bisphosphite ligands combined with a suitable alkali metal BArF salt as a regulation agent (RA) provide high regio- and enantioselectivities in the asymmetric hydroformylation (AHF) of three heterocyclic olefins. The outcome of the AHF could be exquisitely regulated by choosing the appropriate RA with an increase in the ee, the reversal of the regioselectivity, or the complete suppression of one byproduct.
Regioselective hydroformylation of vinylarenes in aqueous media by a sol-gel entrapped rhodium catalyst
Nairoukh, Zackaria,Blum, Jochanan
scheme or table, p. 129 - 133 (2012/06/18)
Two methods for selective hydroformylation of vinylarenes in aqueous media are described. One method relies on the application of [Rh(cod)Cl]2 and a tertiary phosphane entrapped within an ionic liquid-confined silica sol-gel support. The second method utilizes the same rhodium compound, encaged within ionic-liquid-free hydrophobicized sol-gel. Both methods are best carried out at 50 °C in aqueous emulsions or microemulsions that consist of the substrate, a surfactant, a co-surfactant and >89% water. The optimal H 2/CO ratio is between 1 and 1.1. Both methods allow the reuse of the heterogenized catalyst for several runs. While the regioselectivity and the yield are hardly affected by the electronic nature of the substrates, they are significantly dependent on the reaction temperature, on the surfactant employed, and on the hydrophobicity of the support of the catalyst. Despite the use of H2 in the reactions, no transformation of the organometallic catalyst into metallic nanoparticles could be detected.
