14368-40-2Relevant articles and documents
Wadsworth-Emmons reaction: The unique catalytic reaction by a solid base
Choudary, Boyapati M.,Kantam, Mannepalli L.,Reddy, Chinta Reddy V.,Bharathi, Balagam,Figueras, Francois
, p. 191 - 200 (2003)
The near-stoichiometric amount of bases is used both in laboratory and industry in Wadsworth-Emmons (WE) reactions, since the by-product, (EtO) 2P(O)OH, formed in the reaction neutralizes the base into an inert salt. A strategy to design, develop, and evolve the recyclable Mg-Al-hydrotalcite-OtBu (HT-OtBu) by the interaction of KOtBu with the calcined hydrotalcite that transforms a well-defined stoichiometric WE reaction into a catalytic one in an effort to minimize the quantum of effluents released and reduce the cost of the process is described here. HT-OtBu is found to be an efficient solid base for WE reactions for the simple synthesis of α,β-unsaturated esters and nitriles for the first time. The HT-OtBu, composed of various ratios of Mg/Al (i.e., 2, 2.5, and 3) and different contents of tBuO - (Mg/Al:3), and their precursors were prepared and well characterized to draw a correlation between structure and reactivity of the hydrotalcites in WE reactions.
Palladium(0)-catalyzed ring cleavage of cyclobutanone oximes leading to nitriles via β-carbon elimination [28]
Nishimura,Uemura
, p. 12049 - 12050 (2000)
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Sulfur-controlled and rhodium-catalyzed formal (3 + 3) transannulation of thioacyl carbenes with alk-2-enals and mechanistic insights
Wu, Qiuyue,Dong, Ziyang,Xu, Jiaxi,Yang, Zhanhui
supporting information, p. 3173 - 3180 (2021/04/21)
A rhodium-catalyzed denitrogenative formal (3 + 3) transannulation of 1,2,3-thiadiazoles with alk-2-enals is achieved, producing 2,3-dihydrothiopyran-4-ones in moderate to excellent yields. An inverse KIE of 0.49 is obtained, suggesting the reversibility of the oxidative addition of thioacyl Rh(i) carbenes to alk-2-enals. The late-stage structural modifications of steroid compounds are realized. Moreover, our studies show that thioacyl carbenes have different reactivities to those of α-oxo and α-imino carbenes, and highlight the importance of heteroatoms in deciding the reactivities of heterovinyl carbenes.
Copper-Photocatalyzed Contra-Thermodynamic Isomerization of Polarized Alkenes
Bouillon, Jean-Philippe,Brégent, Thibaud,Poisson, Thomas
supporting information, p. 7688 - 7693 (2020/10/09)
The contra-thermodynamic isomerization of α- and β-substituted cinnamate derivatives catalyzed by the Cu(OAc)2/rac-BINAP complex under blue light irradiation is reported. The use of an oxazolidinone template, which favored the complexation of the copper catalyst to the substrate, allowed the E → Z isomerization of the catalytically formed chromophore under simple and robust reaction conditions in good to excellent ratios. The mechanism of this process based on the transient formation of a chromophore was also studied.