136185-86-9Relevant articles and documents
Recyclable polyisobutylene-supported pyridyl N-oxide allylation catalysts
Bergbreiter, David E.,Ortiz-Acosta, Denisse
, p. 5608 - 5610 (2008)
Polyisobutylene (PIB) is a useful soluble polymer support that facilitates catalyst recovery and recycling in liquid-liquid biphasic systems because the long polyisobutylene chain confers high phase selective solubility in the nonpolar phase of polar-nonpolar liquid-liquid biphasic systems on groups attached to the polymer's terminus. This work shows that PIB-supports that are effective with metal catalysts can also facilitate synthesis and use of organocatalysts. This is demonstrated by the use of a PIB-supported pyridyl N-oxide to promote the allylation of several aromatic aldehydes with allyltrichlorosilane. These studies show that a PIB-supported pyridyl N-oxide is a very active recyclable catalyst that promotes the allylation of aromatic aldehydes in yields of up to 99% yield. These PIB-supported pyridyl N-oxide catalysts were recovered in the hexane phase of a hexane/90% EtOH-H2O solvent system and were successfully recycled through 5 cycles with little effect on catalyst efficiency.
Highly efficient allylation of aldehydes promoted by maleic acid in aqueous media
Li, Gui-Long,Zhao, Gang
, p. 2540 - 2542 (2005)
A highly efficient promoter for allylation of aldehydes in aqueous media was developed. Under the promotion of maleic acid, the allylation of various aldehydes can be finished in a short period of reaction time to afford the corresponding homoallylic alco
o-Bis(allyldimethylsilyl)benzene as a remarkably effective allylation agent for carbonyl compounds with Bu4NF catalyst
Asao, Naoki,Shibato, Atsushi,Itagaki, Yoshifumi,Jourdan, Fabrice,Maruoka, Keiji
, p. 3177 - 3180 (1998)
A new type of fluoride ion catalyzed allylation agent, o- bis(allyldimethylsilyl)benzene (1a) and bis(allyldimethylsilyl)methane (1b), can be successfully utilized for various carbonyl substrates. The rate acceleration is ascribable to the shift of equili
Palladium-catalyzed anti-Markovnikov oxidative acetalization of activated olefins with iron(iii) sulphate as the reoxidant
Fernandes, Rodney A.,Kumar, Praveen,Yadav, Sandhya S.
, p. 427 - 443 (2022/01/20)
This paper discloses the efficient palladium-catalyzed anti-Markovnikov oxidative acetalization of activated terminal olefins with iron(iii) sulfate as the reoxidant. This methodology requires mild reaction conditions and shows high regioselectivity toward anti-Markovnikov products and compatibility with a wide range of functional groups. Iron(iii) sulphate was the sole reoxidant used in this method. Various olefins like vinylarenes, aryl-allylethers, aryl or benzyl acrylates and homoallylic alcohols all reacted well providing anti-Markovnikov acetals, some of which represent orthogonally functionalized 1,3- and 1,4-dioxygenated compounds.
Organocatalytic Asymmetric Synthesis of Cyclic Acetals with Spirooxindole Skeleton
Shikari, Amit,Mandal, Koushik,Chopra, Deepak,Pan, Subhas Chandra
supporting information, p. 58 - 63 (2021/11/09)
An organocatalytic asymmetric synthesis of cyclic acetal with spirooxindole skeleton has been developed via a domino reaction between isatin and γ-hydroxy enones. Bifunctional squaramide catalyst with adamantyl motif was found to be the most effective for the cascade reaction. With 10 mol% of the catalyst, the desired products were obtained in 1.8:1 to 9:1 diastereo- and 86% to >99% enantioselectivities from a range of substituted isatins and γ-hydroxy enones. (Figure presented.).
Visible Light-Promoted Recyclable Carbon Nitride-Catalyzed Dioxygenation of β,γ-Unsaturated Oximes
Fu, Xiao-Yang,Si, Ya-Feng,Qiao, Li-Peng,Zhao, Yu-Fen,Chen, Xiao-Lan,Yu, Bing
supporting information, p. 574 - 580 (2021/11/13)
A visible-light-induced dioxygenation of β,γ-unsaturated oximes for the synthesis of diverse useful isoxazolines bearing a hydroxyl moiety was developed by employing graphitic carbon nitride (g-C3N4) as a heterogeneous photocatalyst under an air atmosphere. Noted that, the eminent advantages of this metal-free protocol include step economy, easy operation, a recyclable photocatalyst, external reductant-/oxidant-free and mild reaction conditions. Additionally, mechanistic studies indicated hydroxyl radical was generated under the photocatalysis of g-C3N4.
Photoredox Allylation Reactions Mediated by Bismuth in Aqueous Conditions
Potenti, Simone,Gualandi, Andrea,Puggioli, Alessio,Fermi, Andrea,Bergamini, Giacomo,Cozzi, Pier Giorgio
supporting information, p. 1624 - 1627 (2021/02/05)
Organometallic allylic reagents are widely used in the construction of C?C bonds by Barbier-type reactions. In this communication, we have described a photoredox Barbier allylation of aldehydes mediated by bismuth, in absence of other metals as co-reductants. Mild reaction conditions, tolerance of oxygen, and use of aqueous solvent make this photoredox methodology attractive for green and sustainable synthesis of homoallylic alcohols.
Copper-catalyzed radical oxyallylation of olefins for the construction of alkene-containing isoxazolines
He, Xiaoxue,Qian, Lijie,Dai, Yuyu,Yan, Xinhuan,Li, Xiaoqing,Xu, Xiangsheng
supporting information, (2021/05/31)
A radical-mediated approach to alkene oxyallylation using allylic oximes is described. The reaction proceeds under copper-catalytic redox-neutral conditions and tolerates various functional groups. This protocol thus enables the synthesis of structurally valuable isoxazolines and the introduction of a versatile olefin motif in a single step.
Ni-Catalyzed 1,2-Diarylation of Alkenyl Ketones: A Comparative Study of Carbonyl-Directed Reaction Systems
Apolinar, Omar,Derosa, Joseph,Engle, Keary M.,Karunananda, Malkanthi K.,Kleinmans, Roman,Li, Zi-Qi,Tran, Van T.,Wisniewski, Steven R.
supporting information, p. 5311 - 5316 (2021/07/26)
A nickel-catalyzed 1,2-diarylation of alkenyl ketones with aryl iodides and arylboronic esters is reported. Ketones with a variety of substituents serve as effective directing groups, offering high levels of regiocontrol. A representative product is diversified into a wide range of useful products that are not readily accessible via existing 1,2-diarylation reactions. Preliminary mechanistic studies shed light on the binding mode of the substrate, and Hammett analysis reveals the effect of electronic factors on initial rates.
Catalytic Photoredox Allylation of Aldehydes Promoted by a Cobalt Complex
Gualandi, Andrea,Rodeghiero, Giacomo,Perciaccante, Rossana,Jansen, Thomas Paul,Moreno-Cabrerizo, Cristina,Foucher, Charles,Marchini, Marianna,Ceroni, Paola,Cozzi, Pier Giorgio
supporting information, p. 1105 - 1111 (2021/01/04)
The preparation of homoallylic alcohols by addition of organometallic allyl compounds to carbonyls is an important strategy in organic chemistry. Allylating organometallic cobalt species can be generated employing stoichiometric quantities of Zn acting as reductant. To avoid the employment of stoichiometric amount of Zn, we have developed an allylation reaction of aromatic and aliphatic aldehydes promoted by photoredox catalysis in the presence of a cobalt complex, and we present herein a full account of our research. In the presence of the abundant CoBr2 (10 mol %), 4,4′-di-tert-butyl-2,2′-dipyridyl (dtbbpy, 10 mol %), allyl acetate (3 equiv.), [Ir(dtbbpy)(ppy)2]PF6 (ppy=2-phenylpyridine, 2 mol %), and N,N-diisopropylethylamine (4 equiv.), an allylation of aldehydes is taking place, in moderate to good yields. Substrates scope, limitations, and photophysical investigations of this new process are reported. (Figure presented.).
