62912-75-8Relevant academic research and scientific papers
Highly Regio- and Enantioselective Alkoxycarbonylative Amination of Terminal Allenes Catalyzed by a Spiroketal-Based Diphosphine/Pd(II) Complex
Liu, Jiawang,Han, Zhaobin,Wang, Xiaoming,Wang, Zheng,Ding, Kuiling
, p. 15346 - 15349 (2015/12/26)
An enantioselective alkoxycarbonylation-amination cascade process of terminal allenes with CO, methanol, and arylamines has been developed. It proceeds under mild conditions (room temperature, ambient pressure CO) via oxidative Pd(II) catalysis using an aromatic spiroketal-based diphosphine (SKP) as a chiral ligand and a Cu(II) salt as an oxidant and affords a wide range of α-methylene-β-arylamino acid esters (36 examples) in good yields with excellent enantioselectivity (up to 96% ee) and high regioselectivity (branched/linear > 92:8). Preliminary mechanistic studies suggested that the reaction is likely to proceed through alkoxycarbonylpalladation of the allene followed by an amination process. The synthetic utility of the protocol is showcased in the asymmetric construction of a cycloheptene-fused chiral β-lactam.
Fe(0)-mediated synthesis of tri- and tetra-substituted olefins from carbonyls: An environmentally friendly alternative to Cr(II)
Falck,Bejot, Romain,Barma, Deb K.,Bandyopadhyay, Anish,Joseph, Suju,Mioskowski, Charles
, p. 8178 - 8182 (2007/10/03)
Fe(0) was investigated as a cost-effective, environmentally friendly alternative to Cr(II) for the olefination of carbonyls by activated polyhalides. In many instances, Fe(0) was equivalent or superior to Cr(II). Notably, Fe(0), but not Cr(II), proved com
Preparation of Functionalized Cyclobutenones and Phenolic Compounds from α-Diazo β-ketophosphonates
Andriamiadanarivo, Rindra,Pujol, Bernard,Chantegrel, Bernard,Deshayes, Christian,Doutheau, Alain
, p. 7923 - 7924 (2007/10/02)
When heated in refluxing benzene or toluene, α-diazo β-ketophosphonates 2, prepared in three steps from aldehydes or ketones, gave rise to functionalized cyclobutenones 4 or phenolic compounds 5.These products are formed by electrocyclisation respectively of a vinyl or dienylketene, resulting from a Wolff rearrangement.
The Allopolarization Principle and its Applications, VI. The Alkylation of Enolate Anions: Polarity and Regioselectivity
Gompper, Rudolf,Vogt, Hans-Hubert,Wagner, Hans-Ulrich
, p. 1644 - 1652 (2007/10/02)
The O/C methylation ratio in the reaction of sodium enolates with dimethylsulfate depends on the polar (electronic) effect of substituents.The relative ?-charge density Px/y = lx/ly can be used as a measure for the polarity of ambifunctional anions; in case of enolate anions PO/C = lO/lC.The change of the regioselectivity Sf = log QO/QC in the alkylation of enolates is a function of a change in the polarity PO/C; ΔSf=f(ΔPx/y).The polar effect of substituents influences the charge control during the alkylation process via a change of the polarity of the enolate system: The higher the polarity of the anion, the stronger the charge control and the higher the yield of enol ether (O-alkylation). - Keywords: Alkylation, Enolate Anions
