41976-80-1Relevant academic research and scientific papers
Trityl Antimonate-Catalyzed Sequential Reactions of Epoxides with Silylated Nucleophiles. Rearrangement of Epoxides and C-C or C-O Bond Forming Nucleophilic Reaction onto the Intermediate Carbonyl Compounds
Harada, Tsunehiro,Mukaiyama, Teruaki
, p. 882 - 891 (1993)
In the presence of a catalytic amount of trityl hexafluoroantimonate, sequential reactions of epoxides with silylated nucleophiles, rearrangement of epoxides and C-C or C-O bond forming nucleophilic reaction onto the intermediate carbonyl compounds, proceed smoothly to afford the corresponding products in fairly good yields by one-pot procedure.Trityl hexafluoroantimonate (5 mol percent) efficiently promotes the above plural sequential reactions.
Structural Dependence on Photoaddition of Methanol to Arylalkenes. Solvent and Additive Effects on Photoinduced Electron Transfer Reaction
Mizuno, Kazuhiko,Nakanishi, Isao,Ichinose, Nobuyuki,Otsuji, Yoshio
, p. 1095 - 1098 (1989)
The 9,10-dicyanoanthracene(DCA)-sensitized photoaddition of methanol to arylalkenes occurred both in benzene and acetonitrile to give the corresponding anti-Markownikoff type adducts.The efficiency of the photoreaction depended on the solvents and the str
α-Alkylation of Ketones with Alkenes Enabled by Photoinduced Activation of Silyl Enol Ethers in the Presence of a Small Amount of Water
Hirata, Tsubasa,Ogasawara, Yoshihiro,Yamashita, Yasuhiro,Kobayashi, Shū
supporting information, p. 5693 - 5697 (2021/08/03)
Under blue-light irradiation conditions with a photocatalyst [1,2,3,5-tetrakis(carbazol-9-yl)-4,6-dicyanobenzene], silyl enol ethers reacted with alkenes in the presence of a small amount of water to afford the α-alkylation products in good to high yields. A thiol cocatalyst was found to expand the substrate scope of the reaction.
The Concept of Photozymes: Short Peptides with Photoredox Catalytic Activity for Nucleophilic Additions to α-Phenyl Styrenes
Sack, Daniel,Wagenknecht, Hans-Achim
, p. 6400 - 6407 (2021/11/18)
Conventional photoredox catalytic additions of alcohols to olefins require additives, like thiophenol, to promote back electron transfer. The concept of “photozymes” assumes that forward and backward electron transfer steps in a photoredox catalytic cycle
Catalytic Amination of β-(Hetero)arylethyl Ethers by Phosphazene Base t-Bu-P4
Shigeno, Masanori,Nakamura, Ryutaro,Hayashi, Kazutoshi,Nozawa-Kumada, Kanako,Kondo, Yoshinori
supporting information, p. 6695 - 6699 (2019/09/07)
We describe the catalytic amination of β-(hetero)arylethyl ethers with amines using the organic superbase t-Bu-P4 to obtain β-(hetero)arylethylamines. The reaction has a broad substrate scope and allows the transformations of electron-deficient and electron-neutral β-(hetero)arylethyl ethers with various amines including pyrrole, N-alkylaniline, diphenylamine, aniline, indole, and indoline derivatives. Mechanistic studies indicate a two-reaction pathway of MeOH elimination from the substrate to form a (hetero)arylalkene followed by the hydroamination of the alkene.
Photocatalytic Dehydrogenative Cross-Coupling of Alkenes with Alcohols or Azoles without External Oxidant
Yi, Hong,Niu, Linbin,Song, Chunlan,Li, Yiying,Dou, Bowen,Singh, Atul K.,Lei, Aiwen
supporting information, p. 1120 - 1124 (2017/01/18)
Direct cross-coupling between alkenes/R-H or alkenes/RXH is a dream reaction, especially without external oxidants. Inputting energy by photocatalysis and employing a cobalt catalyst as a two-electron acceptor, a direct C?H/X?H cross-coupling with H2evolution has been achieved for C?O and C?N bond formation. A new radical alkenylation using alkene as the redox compound is presented. A wide range of aliphatic alcohols—even long chain alcohols—are tolerated well in this system, providing a new route to multi-substituted enol ether derivatives using simple alkenes. Additionally, this protocol can also be used for N-vinylazole synthesis. Mechanistic insights reveal that the cobalt catalyst oxidizes the photocatalyst to revive the photocatalytic cycle.
Photocatalytic nucleophilic addition of alcohols to styrenes in Markovnikov and anti-Markovnikov orientation
Weiser, Martin,Hermann, Sergej,Penner, Alexander,Wagenknecht, Hans-Achim
, p. 568 - 575 (2015/06/08)
The nucleophilic addition of methanol and other alcohols to 1,1-diphenylethylene (1) and styrene (6) into the Markovnikov- and anti-Markovnikov-type products was selectively achieved with 1-(N,N-dimethylamino)pyrene (Py) and 1,7-dicyanoperylene-3,4:9,10-tetracarboxylic acid bisimide (PDI) as photoredox catalysts. The regioselectivity was controlled by the photocatalyst. For the reductive mode towards the Markovnikov-type regioselectivity, Py was applied as photocatalyst and triethylamine as electron shuttle. This approach was also used for intramolecular additions. For the oxidative mode towards the anti-Markovnikov-type regioselectivety, PDI was applied together with Ph-SH as additive. Photocatalytic additions of a variety of alcohols gave the corresponding products in good to excellent yields. The proposed photocatalytic electron transfer mechanism was supported by detection of the PDI radical anion as key intermediate and by comparison of two intramolecular reactions with different electron density. Representative mesoflow reactor experiments allowed to significantly shorten the irradiation times and to use sunlight as "green"light source.
The photochemistry of 4-halobenzonitriles and 4-haloanisoles with 1,1-diphenyiethene in methanol. Homolytic cleavage versus electron-transfer pathways
Mangion, Dino,Arnold, Donald R.
, p. 1655 - 1670 (2007/10/03)
The photochemical reactivity of a series of 4-halobenzonitriles and 4-haloanisoles with 1,1-diphenylethene in a nucleophilic solvent (methanol) has been investigated. Analysis of the photochemical reactions involving the 4-halobenzonitriles revealed formation of alkene-methanol adducts, such as 1-methoxy-2,2-diphenylethane, 1-methoxy-2,2-diphenylethene, and 1,1-dimethoxy-2,2-diphenylethane, indicative of a photochemical electron-transfer mechanism. These products were not significant in the photochemical reactions involving the 4-haloanisoles. Both the 4-halobenzonitriles and the 4-haloanisoles produced an 'arene-alkene-methanol Markovnikov adduct, 1-aryl-2-methoxy-2,2-diphenylethane (aryl = 4-cyanophenyl or 4-methoxyphenyl). This compound was shown to undergo an acid-catalysed elimination to 1-aryl-2,2-diphenylethene under the reaction conditions, which subsequently underwent a 6π-electrocyclization to the 3-substituted(cyano or methoxy)-9-phenylphenanthrene. Possible mechanisms for the observed reactivity are discussed and evaluated.
Methanol-Incorporated Photoaddition of N-Methyl-1,2-naphthalenedicarboximide with Alkenes and Dienes
Kubo, Yasuo,Mihara, Mariko,Araki, Takeo
, p. 241 - 248 (2007/10/02)
Irradiation of acetonitrile-methanol solutions of N-methyl-1,2-naphthalenedicarboximide (1b) with 1,1-diphenylethylene gave a methanol-incorporated adduct at a carbonyl carbon atom in 1b together with 2,2-diphenylethyl methyl ether as a typical electron-transfer photosensitized product.The photoreaction of 1b with α-methylstyrene, styrene (2c), or 2-methyl-2-butene in the same solvent system gave a regio-isomeric pair of a mixture of two diastereomers of methanol-incorporated adducts at carbonyl atoms.The irradiation of 1b with 2,3-dimethyl-2-butene and ethyl vinyl ether (2h) in benzene-methanol afforded methanol- incorporated adducts, although no reaction was observed for irradiation in acetonitrile-methanol.The irradiation of 1b with 2,5-dimethyl-2,4-hexadiene in acetonitrile-methanol also resulted in the formation of methanol-incorporated adducts.The values of the free-energy change associated with an electron-transfer (ΔGet) from the alkenes to the singlet excited state of 1b and fluorescence quenching rate constants support the photochemical single-electron-transfer mechanism for the addition.A preferential addition at the carbonyl carbon atom in 1b as well as that at the more sterically hindered carbonyl carbon atom in the reaction of 1b with 2c and 2h is explainable on the basis of the spin densities of the radical anion of 1b derived by a photochemical single-electron-transfer.
