51469-48-8Relevant academic research and scientific papers
Synthesis of Ketones by C?H Functionalization of Aldehydes with Boronic Acids under Transition-Metal-Free Conditions
Roscales, Silvia,Csáky, Aurelio G.
supporting information, p. 8728 - 8732 (2021/03/16)
A method for the synthesis of ketones from aldehydes and boronic acids via a transition-metal-free C?H functionalization reaction is reported. The method employs nitrosobenzene as a reagent to drive the simultaneous activation of the boronic acid as a boronate and the activation of the C?H bond of the aldehyde as an iminium species that triggers the key C?C bond-forming step via an intramolecular migration from boron to carbon. These findings constitute a practical, scalable, and operationally straightforward method for the synthesis of ketones.
Tin(II) chloride mediated coupling reactions between alkynes and aldehydes
Masuyama, Yoshiro,Takamura, Wataru,Suzuki, Noriyuki
, p. 8033 - 8038 (2014/01/06)
Tin(II) chloride, which is insensitive to water and air, mediated the coupling reaction between alkynes and aldehydes as a Lewis acid in nitromethane to produce (E)-α,β-unsaturated ketones by a skeletal transformation in which one alkynic carbon atom changed into an oxo carbon atom accompanied by the cleavage of a C=O bond in the starting aldehydes. This coupling reaction was promoted by a catalytic amount of a primary or secondary alkanol. The coupling reaction between 1-deuterio-2-phenylethyne and benzaldehyde with BuOH afforded 1,3-diphenyl-2-deuterio-2-propenone (2-deuteriation: 94 % D), whereas the coupling reaction between phenylethyne and benzaldehyde with BuOD afforded 1,3-diphenyl-2-propenone (2-deuteriation: 0 % D). Because almost no exchange between hydrogen and deuterium at the 2-position of 1,3-diphenyl-2-propenone occurs in either of the reactions, the coupling reaction between alkynes and aldehydes with tin(II) chloride is presumed to proceed by nucleophilic addition of alkynes to aldehydes. The cleavage of the C-O single bond generated by the nucleophilic addition might be induced by the strong oxophilicity of tin. Coupling reactions occur between alkynes and aldehydes mediated by tin(II) chloride as a Lewis acid to produce (E)-α,β-unsaturated ketones by a skeletal transformation in which an alkynic carbon atom changes into an oxo carbon atom accompanied by cleavage of the C=O bond in the starting aldehydes. This coupling reaction is promoted by a catalytic amount of a primary or secondary alkanol. Copyright
Heteropoly compound catalyzed synthesis of both z- and e-α,β- unsaturated carbonyl compounds
Egi, Masahiro,Umemura, Megumi,Kawai, Takuya,Akai, Shuji
scheme or table, p. 12197 - 12200 (2012/01/19)
An EZ switch: The cationic species of the heteropoly compounds has a critical impact on the Z/E selectivity of the Meyer-Schuster rearrangement of propargyl alcohols (see scheme). The isolation of the thermodynamically unfavorable Z-α,β-unsaturated carbonyl compounds is notable. The high Z selectivities were obtained at a reaction temperature as high as 50°C.
Mo-Au combo catalysis for rapid 1,3-rearrangement of propargyl alcohols into α,ss-unsaturated carbonyl compounds
Egi, Masahiro,Yamaguchi, Yoshiko,Fujiwara, Noboru,Akai, Shuji
supporting information; experimental part, p. 1867 - 1870 (2009/04/18)
The combination of Mo and cationic Au catalysts dramatically accelerated the rearrangement of diverse propargyl alcohols, which includes a short reaction time, mild conditions, and high product yields. A practical application to the highly challenging primary propargyl alcohols and the N-alkynyl amides is achieved.
An atom-economic and selective ruthenium-catalyzed redox isomerization of propargylic alcohols. An efficient strategy for the synthesis of leukotrienes
Trost, Barry M.,Livingston, Robert C.
supporting information; experimental part, p. 11970 - 11978 (2009/02/05)
Catalytic ruthenium complexes in conjunction with an indium cocatalyst and Broensted acid isomerize primary and secondary propargylic alcohols in good yields to provide trans enals and enones exclusively. Readily available indenylbis(triphenylphosphine)ruthenium chloride, in the presence of indium triflate and camphorsulfonic acid, gives the best turnover numbers and reactivity with the broadest range of substrates. Deuterium labeling experiments suggest that the process occurs through propargylic hydride migration followed by protic cleavage of the resultant vinylruthenium intermediate. Application of this method to the synthesis of leukotriene B4 demonstrates its utility and extraordinary selectivity.
Ring-opening of isoxazolidine nucleus: Competitive formation of α,β-enones and tetrahydro-1,3-oxazines
Casuscelli, Franco,Chiacchio, Ugo,Rescifina, Antonio,Romeo, Roberto,Romeo, Giovanni,Tommasini, Silvana,Uccella, Nicola
, p. 2979 - 2990 (2007/10/02)
Treatment of isoxazolidine derivatives with methyl iodide, followed by simple heating with aqueous NaOH, gives rise to a competitive formation of α,β-enones and tetrahydro-1,3-oxazines. The ring-opening process is controlled by the stereochemistry of H5 which represents the driving factor of two competitive reaction routes.
Allylidenetriphenylphosphorane as a Bifunctional Reagent: Synthesis of Cyclopentenones and α,β-Unsaturated Ketones with (3-(Alkoxycarbonyl)-2-ethoxy-2-propylidene)triphenylphosphorane
Hatanaka, Minoru,Himeda, Yuichiro,Imashiro, Ritsuo,Tanaka, Yasuhiro,Ueda, Ikuo
, p. 111 - 119 (2007/10/02)
When (3-(ethoxycarbonyl)-2-ethoxy-2-propenylidene)triphenylphosphorane (6) was allowed to react with α-bromo ketones 8a-d in dichloromethane in the presence of Cs2CO3 at room temperature, a annulation occured and led to the formation of the corresponding 2-ethoxycyclopentadienes 9a-d in excellent yields.Similarly, bromo thioester 8g underwent the annulation to give 4-(ethylthio)cyclopentadiene 9g.Secondary bromides 2-bromo-3-pentanone and 2-bromocyclohexanone also afforded tetrasubstituted cyclopentadienes 9e and 9f in moderate yields when 2 equiv of 6 was used.The annulation is belived to proceed through a sequence involving a stepwise alkylation at the γ position of 6 and an intramolecular Wittig reaction because of the fact that intermediate 11 was isolated.The resulting 2-ethoxycyclopentadienes 9a-g were converted quantitatively into the corresponding cyclopentenones 10a-g upon mild acid treatment.Furthermore, allylidenetriphenylphosphorane underwent a carbon elongation at both ends of the three-carbon unit via an alkylation-Wittig reaction sequence. (3-(tert-Butoxycarbonyl)-2-ethoxy-2-propenylidene)triphenylphosphorane (7) reacted first with alkyl halides and then with aldehydes in the presence of Cs2CO3 to give enol ethers 23a-f, which were converted into α,β-unsaturated ketones 20, 21, and 25c-f by hydrolysis of the enol ether and then decarboxylation.In this way, shogaol (29), the pungent principle component of ginger, was conveniently synthesized starting from 2-methoxy-4-methylphenol.
Synthesis of α,β-Unsaturated Ketones Using Allylidenetriphenylphosphorane as a Three-carbon Unit
Hatanaka, Minoru,Imashiro, Ritsuo,Ueda, Ikuo
, p. 2253 - 2256 (2007/10/02)
3-Alkoxycarbonyl-2-ethoxy-2-propenylidenetriphenylphosphorane reacts in turn with alkyl halides and aldehydes in the presence of base via a one-pot procedure to give moderate to good yields of conjugated enol ethers.Hydrolysis of the conjugated enol ethers and subsequent decarboxylation provide a novel route to α,β-unsaturated ketones.
Palladium(0)-catalyzed isomerization of α,β-epoxy ketones to β-diketones
Suzuki, M.,Watanabe, A.,Noyori, R.
, p. 230 - 236 (2007/10/02)
In the presence of catalytic amounts of tetrakis(triphenylphosphine)palladium(0) and 1,2-bis(diphenylphosphino)ethane, α,β-epoxy ketones isomerize to the corresponding β-diketones in high yields.Both open-chain and cyclic substrates can be used.Possible reaction mechanisms are discussed.
