826-18-6Relevant articles and documents
COMPARAISON ENTRE LE ROLE DE L'EAU ET CELUI D'UN ETHER COURONNE DANS LE CADRE DE LA REACTION DE WITTIG REALISEE EN MILIEU HETEROGENE : LIQUIDE-SOLIDE
Delmas, M.,Bigot, Y. Le,Gaset, A.
, p. 4831 - 4834 (1980)
The similar results issued from the use of water and the 18-crown-6 ether for the Wittig reaction (in liquid-solid two-phase system) allowed us to obtain vary high yields in olefin starting from aromatic as well as aliphatic aldehydes.
Stereoselective Rhodium-Catalyzed Isomerization of Stereoisomeric Mixtures of Arylalkenes
Yang, Hongxuan,Dong, Wenke,Wang, Wencan,Li, Tao,Zhao, Wanxiang
supporting information, p. 2833 - 2840 (2020/10/06)
A new efficient method for the synthesis of a high ratio of E -alkenes from E / Z mixtures of alkenes with B 2pin 2in the presence of a rhodium catalyst is described. This reaction features mild reaction conditions, broad functional group tolerance, and highly great application potential.
New Insights into the Reaction Capabilities of Ionic Organic Bases in Cu-Catalyzed Amination
Lo, Quintin A.,Sale, David,Braddock, D. Christopher,Davies, Robert P.
, p. 1944 - 1951 (2019/02/19)
The application of ionic organic bases in the copper-catalyzed amination reaction (Ullmann reaction) has been studied at room temperature, with sub-mol-% catalyst loadings, and with more challenging amines at elevated temperatures. The cation present in the base has been shown to have little effect on the reaction at standard catalyst and ancillary ligand loadings, whereas the choice of anion is crucial for good reactivity. A substrate scope carried out at room temperature with the best performing bases, TBAM and TBPM, showed both bases to be highly effective under these mild reaction conditions. Moreover, under sub-mol % catalyst loadings and room temperature conditions, TBPM gave good to excellent yields for a number of different amines and functionalized aryl iodides (14 examples). However, reactions involving more challenging amines gave little or no yield. By using more forceful conditions (120 °C) moderate to excellent yields of cross-coupled products containing more challenging amines was achievable using TBPM and to a lesser extent with TBAM. As part of this work a study on the stability of the organic bases at 120 °C was undertaken. TBAM is shown to decompose to give nBu3N and mono-butylmalonate at higher temperatures, and this can be correlated to a decrease in performance in the coupling reaction. The phosphonium cations in TBPM did not undergo analogous reactivity but were shown instead to experience some degree of deprotonation at the α-CH2 to generate phosphonium ylides. This however did not lead to a significantly degradation in the activity of the TBPM in the cross-coupling reaction.
