108349-24-2Relevant academic research and scientific papers
Radical additions of acyclic and cyclic ethers to alkenes via an allyl transfer reaction involving phthalimido-N-oxyl radical
Patil, Shradha V.,Tanko, James M.
, p. 7849 - 7858 (2016)
Direct functionalization of rudimentary and cheap starting materials to yield complex value added products is of great interest to synthetic chemists. Particularly, direct functionalization of cheap commodity molecules that have been traditionally considered inert to known reactions are of widespread interest. We have previously demonstrated the functionalization of benzylic C–H bonds via an allyl transfer reaction using various allyl-phthalimido-N-oxyl substrates. In this work, we demonstrate the extension of our mild, metal-free, and neutral allyl transfer methodology to the direct functionalization of ethers. The C–H bond in α position to the ether oxygen in various acyclic and cyclic ethers was functionalized in high yields demonstrating wide substrate scope for this transformation. Furthermore, selective mono-functionalization of symmetrical cyclic ethers and regioselective functionalization of unsymmetrical ethers was achieved, thus demonstrating further utility of this reaction. Finally, kinetic chain length measurements were performed, which provided valuable insights into the initial rates and efficiency of the chain process involving the phthalimido-N-oxyl (PINO[rad]) radical.
Selective photoredox decarboxylation of α-ketoacids to allylic ketones and 1,4-dicarbonyl compounds dependent on cobaloxime catalysis
Zhang, Hong,Xiao, Qian,Qi, Xu-Kuan,Gao, Xue-Wang,Tong, Qing-Xiao,Zhong, Jian-Ji
supporting information, p. 12530 - 12533 (2020/11/02)
A photoredox/cobaloxime co-catalyzed coupling reaction of α-ketoacids and methacrylates to obtain allylic ketones is described. Without the cobaloxime catalyst, 1,4-dicarbonyl compounds are generated. The cobaloxime catalyst enables dehydrogenation to generate the formation of new olefins. The generality, good substrate scope and mild conditions are good features in the photoredox/cobaloxime catalysis protocol, and this method will provide new opportunities for the functionalization of more olefins.
Method for preparing allyl ketone compound through visible light and cobalt synergistic catalysis
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Paragraph 0039-0056, (2020/07/21)
The invention discloses a method for preparing an allyl ketone compound through visible light and cobalt synergistic catalysis. The method comprises the following steps: using alpha-carbonyl carboxylic acid and methacrylate olefin as reaction substrates; dissolving potassium tert-butoxide or 2, 6-dimethylpyridine serving as alkali, using 4-CzIPN as a visible-light-induced photocatalyst and using acobalt complex as a synergistic catalyst in a solvent to obtain a mixed solution, and irradiating the mixed solution with visible light under the protection of inert gas to obtain the allyl ketone compound. The reaction can be realized by visible light irradiation at room temperature, the method is simple and convenient to operate, the raw materials are easy to obtain, the whole reaction system is very green and environmentally friendly, reaction conditions are mild, the reaction can be completed under the action of a catalytic amount of the photocatalyst and the cobalt complex, equivalent additional oxidants are not needed, the reaction system is efficient and economical and is suitable for gram-level reaction on an amplified large scale and has huge potential large-scale application value.
Photoinduced free radical chemistry of the acyl tellurides: Generation, inter- and intramolecular trapping, and ESR spectroscopic identification of acyl radicals
Crich, David,Chen, Chen,Hwang, Jae-Taeg,Yuan, Hongwei,Papadatos, Aristotle,Walter, Robert I.
, p. 8937 - 8951 (2007/10/02)
Acyl tellurides are prepared in good to excellent yield by the reaction of sodium aryl tellurides with acyl chlorides, or mixed anhydrides, and are found to be moderately air-stable substances. In contrast to previous literature reports, acyl tellurides of aryl and vinyl carboxylic acids are found to be excellent sources of acyl radicals on photolysis with a simple white light source. The acyl radicals so generated may be trapped intermolecularly by dichalcogenides, or by TEMPO in excellent yield. Trapping by N-tert-butyl-α-phenyl nitrone produces a stable nitroxide radical which has been characterized by ESR spectroscopy. The very efficient trapping of acyl radicals by acyl tellurides themselves is demonstrated by a crossover experiment. Acyl tellurides are shown to participate in very efficient radical cyclization reactions onto alkenes with the formation of five-, six-, and eight-membered rings. The immediate products of the cyclizations onto alkenes are α-[(aryltelluro)methyl] ketones and the chemistry of these relatively unstable species is briefly described. Treatment with hydrogen peroxide affords α-methylene ketones in high yield. When elimination of the aryl telluro group is not possible the α-[(aryltelluro)methyl] ketones are stable species that may subsequently be employed in further radical chain reactions, for example with tributyltin hydride and methyl acrylate. Cyclization onto alkynes yields α-[(aryltelluro)methylene] ketones which are stable species and which take part in substitution reactions with higher order cuprates or with diphenyl diselenide.
A SIMPLE AND GENERAL APPROACH FOR THE SYNTHESIS OF 2-SUBSTITUTED 4-ETHOXYCARBONYLFURAN
Anand, Ramesh C.,Singh, Vibha
, p. 1333 - 1336 (2007/10/02)
A four step strategy has been devised to synthesize 2-substituted 4-ethoxycarbonylfuran starting from an aldehyde.
A New Method for the Preparation of α- Methylene-γ-butyrolactones Using 3-Ethoxycarbonyl-3-(phenylsulphonyl)cyclobutanone
Fujiwara, Tooru,Morita, Koichi,Takeda, Takeshi
, p. 1524 - 1527 (2007/10/02)
The reaction of 3-ethoxycarbonyl-3-(phenylsulphonyl)cyclobutanone with Grignard reagent or aryllithium gave 1-(alkyl or aryl)-3-ethoxycarbonyl)cyclobutanol which was treated with potassium hydride, reduced with LiBH4 in the presence of ZnCl2, and treated
REACTIONS RELATED TO COENZYME B12 DEPENDENT REARRANGEMENTS: METAL MEDIATED FREE RADICAL ACYL MIGRATIONS IN METHYL AND CYCLOPROPYL SUBSTITUTED MODELS
Best, Wayne M.,Widdowson, David A.
, p. 5943 - 5954 (2007/10/02)
Free radicals generated from the methylmalonylcoenzyme A mutase model substrates (3) and (4) by chromium(II) reduction, or by pyrolysis of the analogous cobaloximes, underwent -migration only in the acyl series (R=Ph, Me) and not the critical ester series (R=OEt, SBu).The mechanism of the migration was implied by incorporation into (4) of the cyclopropyl ring, the opening of which demonstrated the free radical nature of rearranged intermediate.
Reactivite de l'organozincique derive de l'α-bromomethyl acrylate d'ethyle
Alami, N. El.,Belaud, C.,Villieras, J.
, p. 157 - 168 (2007/10/02)
The organozinc derivative (2a) of ethyl α-bromomethyl acrylate is not nucleophilic towards haloalkanes but can be alkylated with chlorotrimethylsilane. 2a is unreactive towards carbon-oxygen single bonds and is unsuitable for conjugate addition (α-enones and α,β-ethylenic esters).Its acylation can be carried out in DME in the presence of palladium(0) catalyst.Reactions with carbon-oxygen and and carbon-nitrogen double bonds permit the preparation of α-methylene γ-butyrolactones and lactams without the formation of side-products.This route is especially suitable for reactions with substrates such as imines that are both nucle ophilic and electrophilic.
Reactions Potentially Related to Coenzyme B12 Dependent Rearrangements: Observations on the Radical -Acyl and -Thiol Ester Migrations
Best, Wayne M.,Cook, Anthony P. F.,Russell, James J.,Widdowson, David A.
, p. 1139 - 1144 (2007/10/02)
Reaction of 2-iodomethyl-2-methyl-3-oxo esters with tributyltin radicals, generated photochemically from hexabutylditin or tributyltin hydride in cyclohexane, or benzene-acetonitrile, resulted in a -acyl migration in 10-63percent yields dependent on the source of tin radical and substrate used.Radical migration was confirmed by the use of tributyltin deuteride.Thiol ester group migration was not observed.A new, highly efficient method for thiol ester synthesis is described.
