3461-38-9Relevant academic research and scientific papers
Copper-Catalyzed 1,2-Methoxy Methoxycarbonylation of Alkenes with Methyl Formate
Budai, Balázs,Leclair, Alexandre,Wang, Qian,Zhu, Jieping
supporting information, p. 10305 - 10309 (2019/06/27)
Reported here is a copper-catalyzed 1,2-methoxy methoxycarbonylation of alkenes by an unprecedented use of methyl formate as a source of both the methoxy and the methoxycarbonyl groups. This reaction transforms styrene and its derivatives into value-added β-methoxy alkanoates and cinnamates, as well as medicinally important five-membered heterocycles, such as functionalized tetrahydrofurans, γ-lactones, and pyrrolidines. A ternary β-diketiminato-CuI-styrene complex, fully characterized by NMR spectroscopy and X-ray crystallographic analysis, is capable of catalyzing the same transformation. These findings suggest that pre-coordination of electron-rich alkenes to copper might play an important role in accelerating the addition of nucleophilic radicals to electron-rich alkenes, and could have general implications in the design of novel radical-based transformations.
Generation of the Methoxycarbonyl Radical by Visible-Light Photoredox Catalysis and Its Conjugate Addition with Electron-Deficient Olefins
Slutskyy, Yuriy,Overman, Larry E.
supporting information, p. 2564 - 2567 (2016/07/06)
Visible-light photoredox-catalyzed fragmentation of methyl N-phthalimidoyl oxalate allows the direct construction of a 1,4-dicarbonyl structural motif by a conjugate addition of the methoxycarbonyl radical to reactive Michael acceptors. The regioselectivity of the addition of this alkoxyacyl radical species to electron-deficient olefins is heavily influenced by the electronic nature of the acceptor, behavior similar to that exhibited by nucleophilic alkyl radicals.
Palladium-catalyzed alkoxycarbonylation of terminal alkenes to produce α,β-unsaturated esters: The key role of acetonitrile as a ligand
Malkov, Andrei V.,Derrien, Nolwenn,Barlog, Maciej,Kocovsky, Pavel
supporting information, p. 4542 - 4547 (2014/05/06)
A mild protocol has been developed for the PdII-catalyzed alkoxycarbonylation of terminal olefins to produce α,β-unsaturated esters with a wide range of substrates. Key features are the use of MeCN as solvent (and/or ligand) to control the reactivity of the intermediate Pd complexes and the combination of CO with O2, which facilitates the CuII-mediated reoxidation of the Pd0 complex to Pd II and prevents double carbonylation. Acetonitrile is the key! A mild protocol has been developed for the PdII-catalyzed alkoxycarbonylation of terminal olefins to produce α,β-unsaturated esters with a wide range of substrates (see scheme). Key features are the use of MeCN as a solvent (and/or ligand) to control the reactivity of the intermediate Pd complexes and the combination of CO with O2, which facilitates the CuII-mediated reoxidation of Pd0 to PdII and prevents double carbonylation.
Highly regioselective palladium-catalysed oxidative allylic C-H carbonylation of alkenes
Chen, Huoji,Cai, Congbi,Liu, Xiaohang,Li, Xianwei,Jiang, Huanfeng
supporting information; experimental part, p. 12224 - 12226 (2011/12/14)
Pd-catalysed direct oxidative carbonylation of allylic C-H bonds with carbon monoxide was first described. This new procedure shows that the inherent requirement for a leaving group in the Tsuji-Trost palladium-catalysed allylic carbonylation can be lifted, which provides a new route for accessing more synthetically useful β-enoic acid esters with high regioselectivity. The Royal Society of Chemistry 2011.
Catalytic asymmetric formation of δ-Lactones from Unsaturated acyl halides
Tiseni, Paolo S.,Peters, Rene
supporting information; experimental part, p. 2503 - 2517 (2010/09/03)
Previously unexplored enantiopure zwitterionic ammonium dienolates have been utilized in this work as reactive intermediates that act as diene components in hetero-Diels-Alder reactions (HDAs) with aldehydes to produce optically active δ-lactones, subunits of numerous bioactive products. The dienolates were generated in situ from E/Z mixtures of a,b- unsaturated acid chlorides by use of a nucleophilic quinidine derivative and Sn (OTf)2 as co-catalyst. The latter component was not directly involved in the cycloaddition step with aldehydes and simply facilitated the formation of the reactive dienolate species. The scope of the cycloaddition was considerably improved by use of a complex formed from Er- (OTf)3 and a simple commercially available norephedrine-derived ligand that tolerated a broad range of aromatic and heteroaromatic aldehydes for a cooperative bifunctional Lewis-acid-/ Lewis-base-catalyzed reaction, providing a,b-unsaturated d-lactones with excellent enantioselectivities. Mechanistic studies confirmed the formation of the dienolate intermediates for both catalytic systems. The active ErIII complex is most likely a monomeric species. Interestingly, all lanthanides can catalyze the title reaction, but the efficiency in terms of yield and enantioselectivity depends directly on the radius of the Ln III ion. Similarly, use of the pseudolanthanides ScIII and YIII also resulted in product formation, whereas the larger La III and other transition metal salts, as well as main group metal salts, proved to be inefficient. In addition, various synthetic transformations of 6- CCl3- or 4-silyl-substituted α,β-unsaturated d-lactones, giving access to a number of valuable δ-lactone building blocks, were investigated.
Tetraphosphine/palladium-catalyzed Heck reactions of aryl halides with disubstituted alkenes
Kondolff, Isabelle,Doucet, Henri,Santelli, Maurice
, p. 8487 - 8491 (2007/10/03)
cis,cis,cis-1,2,3,4-Tetrakis(diphenylphosphinomethyl)cyclopentane/ [PdCl(C3H5)]2 efficiently catalyses the Heck reaction of disubstituted alkenes such as methyl crotonate, ethyl cinnamate, methyl methacrylate or α-methylstyrene with a variety of aryl halides. In the presence of 1,2-disubstituted alkenes the stereoselectivities of the reactions strongly depend on the substituents of the alkenes. Selectivities up to 97% in favor of E-isomers can be obtained for the addition to methyl crotonate. With the 1,1-disubstituted alkenes methyl methacrylate or α-methylstyrene mixtures of products are obtained.
Highly active Pd(II) cyclometallated imine catalysts for the Heck reaction
Ohff, Manuela,Ohff, Andreas,Milstein, David
, p. 357 - 358 (2007/10/03)
The new cyclopalladated, phosphine-free imine complexes 1-3 are exceptional catalysts for the Heck arylation, leading to more than a million turnovers in some cases; the catalysts are very thermally and air stable and are recovered unchanged after the catalysis.
Electron Transfer Profile of Cyclopropanone Acetals in the Nonirradiated Reaction with Tetracyanoethylene, Chloranil, and Dicyanodichlorobenzoquinone
Oku, Akira,Abe, Manabu,Iwamoto, Masaharu
, p. 7445 - 7452 (2007/10/02)
The donor profiles of cyclopropanone acetals 1 and 2 were examined in the reactions with electron acceptors (TCNE, DDQ, chloranil, and 1-cyanonaphthalene).With TCNE under nonirradiating conditions, an exclusive 2 + 2 cycloaddition took place stereospecifically with monosubstituted acetals 1a-c but nonstereospecifically with disubstituted acetals 1d,e.With quinones, a ring-opening of the cyclopropane and its coupling with the quinone took place to give the C (cyclopropane)-O (quinone) adduct 9 (with chloranil) or 10 (with DDQ), the latter of which underwent the elimination of a phenol to produce unsaturated esters 5 and 6.In addition, the intervention of the C (cyclopropane)-C (quinone) adduct 14 (with chloranil) or 15 (with DDQ), both as the precursor of 5 and 6, was also postulated.With 1-cyanonaphthalene, under photolysis, the cis/trans isomerization of 1 and 2 occured.The results provided evidences that cyclopropanone acetals, in general, are prone to function as donors.The mechanism of the reaction with quinones, in particular, was investigated in detail.
Formation of Unsaturated Esters in the Single Electron Transfer Reaction of Cyclopropanone Acetals with Quinones under Non-irradiated Conditions
Abe, Manabu,Oku, Akira
, p. 3551 - 3554 (2007/10/02)
Unsaturated esters were formed from cyclopropanone aceytals in the reaction with DDQ or chloranil, where ring-opened C-C and C-O bonded adducts were the intermediates formed via a SET mechanism resulting in the ester formation.
3-Aryl-3-butenoic Acids and Their Esters: Practical Synthesis from Diketene by the Palladium-Catalyzed Grignard Coupling Reaction and Application as Monomers for the Radical Copolymerization with Styrene
Itoh, Kenji,Harada, Tatsumi,Nagashima, Hideo
, p. 3746 - 3748 (2007/10/02)
Treatment of arylmagnesium bromide with an equimolar amount of zinc chloride followed by the reaction with diketene in the presence of a catalytic amount of PdCl2(PPh3)2 provided an improved synthetic method for 3-aryl-3-butenoic acid in a large scale.App
