38363-23-4Relevant articles and documents
Electrophilic Etherification of α-Heteroaryl Carbanions with Monoperoxyacetals as a Route to Ketene O, O- And N, O-Acetals
Paris, Timothy J.,Schwartz, Chris,Willand-Charnley, Rachel
, p. 2369 - 2384 (2021/02/06)
Alkyl ketene acetals are useful reactants in a variety of synthetic processes, and yet, there are limited routes to their formation as isolable products. We now report the successful synthesis and isolation of heteroaryl ketene acetals through intermolecular transfer of alkoxyl (δ+OR) from electrophilic peroxides to lithiated benzofurans, indoles, and pyridines. Primary and secondary peroxyacetals enable selective transfer of the nonanomeric alkoxy group in moderate to high yield; substrates bearing an electron-donating substituent show enhanced reactivity toward electrophilic oxygen. Heteroaryl ketene acetals are remarkably stable throughout traditional purification techniques; the superior stability of ketene N,O-acetals compared to ketene O,O-acetals is presumably due to increased aromaticity of the indole and pyridine structures. The presented method overcomes typical problems associated with alkyl ketene acetal synthesis as reported products withstood workup and flash column chromatography procedures.
Regioselective Acetoxylation of Terminal Olefins Using a Palladium(II)–Thiadiazole Catalyst
Li, Xiaohan,Sun, Bin,Zhou, Jiadi,Jin, Can,Yu, Chuangming
, p. 2635 - 2638 (2019/04/04)
First-time use of a palladium(II)–thiadiazole catalyst in the allylic oxidation of terminal olefins to linear allylic acetates. Employing this strategy, a range of allylic esters (20 examples) were synthesized in 43 % to 80 % yield with excellent regio- and stereoselectivities.
A survey of sulfide ligands for allylic C-H oxidations of terminal olefins
Le, Chichip Q.,Kunchithapatham, Kamala,Henderson, William H.,Check, Christopher T.,Stambuli, James P.
supporting information, p. 11153 - 11157 (2013/09/02)
Perfect to a THT! Screening a diverse library of thioether ligands led to the discovery of tetrahydrothiophene (THT) as a highly reactive and selective ligand for Pd-catalyzed allylic C-H oxidation reactions (see scheme). This novel ligand system provides some of the highest reported yields for the formation of (E)-linear allylic acetates through allylic C-H activation chemistry (BQ = 1,4-benzoquinone). Copyright
Allylic oxidations of terminal olefins using a palladium thioether catalyst
Henderson, William H.,Check, Christopher T.,Proust, Nicolas,Stambuli, James P.
supporting information; experimental part, p. 824 - 827 (2010/04/06)
"Chemical equation presented" A palladium catalyst that converts terminal olefins to linear allylic acetates at lower catalyst loadings and faster reaction times than current systems is reported. This reaction can be conducted using benzoquinone as the oxidizing agent or catalytic amounts of copper and hydroquinone under one atmosphere of oxygen. Preliminary reactivity studies of π-allylpalladium complexes under our reaction conditions do not provide results similar to those obtained in the catalytic reaction, which may suggest an alternative reaction pathway. The palladium catalyst is ligated by an aryloxyalkyl aryl sulfide, which is identified as a new ligand for homogeneous catalysis.
Conformational mobility and preferences of Allyl-type organometallic intermediates : Dodec-2-eny lpotassium
Franzini, Livia,Moret, Etienne,Schlosser, Manfred
, p. 83 - 87 (2007/10/03)
Alk-2-enylpotassium compounds having the endo conformation are synthetically very valuable precursors of (Z)-olefinic derivatives substituted at the outward allylic position. They may be generated by "stereoconservative" metalation of the readily available (Z)-alk-2-enes by using the superbasic mixture of butyllithium and potassium terf-butoxide or by metalation under similar conditions of stereorandom mixtures of alk-2-enes or alk-1-enes followed by torsional isomerization of the concomitantly formed exo conformers to the thermodynamically more stable endo species. The principal factors that dictate the rate and the extent of the endo/exo equilibration are the substrate geometry, the solvent, the temperature, the reagent stoichiometry, and catalysis Keywords: Torsional (ZIE) isomerization / Selectivity, regio- and stereo- / Allylsilanes / Allylic oxidation VCH Verlagsgescllschaft mbH.
Regiospecific Preparation of Primary Allyl Acetates (2-Alkenyl Acetates)
Martinez, Antonio Garcia,Villalobos, Angeles Cruces,Ruiz, Manuel Oliver
, p. 58 - 60 (2007/10/02)
The reaction of primary, secondary and tertiary allyl alcohols 1 with anhydrous magnesium iodide in benzene gives regiospecifically the primary allyl iodides 2.The corresponding primary allyl acetates 3 are obtained regiospecifically by reaction of 2 with anhydrous sodium acetate in dimethylformamide.
