2047-97-4Relevant academic research and scientific papers
Natural products inspired synthesis of neuroprotective agents against H2O2-induced cell death
Almaliti, Jehad,Nada, Shadia E.,Carter, Bryaune,Shah, Zahoor A.,Tillekeratne, L.M. Viranga
supporting information, p. 1232 - 1237 (2013/03/14)
Stroke is a debilitating disease and the third leading cause of death in the USA, where over 2000 new stroke cases are diagnosed every day. Treatment options for stroke-related brain damage are very limited and there is an urgent need for effective neurop
Mild conversion of propargylic alcohols to α,β-unsaturated enones in ionic liquids (ILs); A new 'metal free' life for the Rupe rearrangement
Nandi, Ganesh C.,Rathman, Benjamin M.,Laali, Kenneth K.
supporting information, p. 6258 - 6263 (2013/10/22)
A mild and selective transition metal free protocol for the conversion of propargylic alcohols to cyclic and acyclic α,β-unsaturated enones via the Rupe rearrangement is reported. The method utilizes the Br?nsted acidic ionic liquid [BMIM-SO3H][OTf] as catalyst and [BMIM][PF 6] as solvent and offers the potential for recycling and reuse of the IL solvent. The feasibility to synthesize bicyclic fused cyclopentenone derivatives via a Rupe → Aldol → Nazarov sequence utilizing this protocol has also been demonstrated.
Enabling the development of N-Heterocyclic Carbene (NHC) catalyzed reactions: Practical methods for the preparation of 1-acyl-2-alkylcycloalkenes from cycloalkanones
Ryan, Sarah J.,Candish, Lisa,Martinez, Ivn,Lupton, David W.
, p. 1148 - 1157 (2011/11/06)
The synthesis of 1-acyl-2-alkylcycloalkenes from a variety of cycloalkanones has been achieved via either-keto enol phosphates or-bromoenones. Both methods exploit simple and readily scalable transformations allowing the preparation of the desired compoun
Iridium complex-catalyzed addition of water and alcohols to non-activated terminal alkynes
Hirabayashi, Tomotaka,Okimoto, Yoshio,Saito, Akiyo,Morita, Masao,Sakaguchi, Satoshi,Ishii, Yasutaka
, p. 2231 - 2234 (2007/10/03)
The addition of water and alcohols to non-activated terminal alkynes was found to be promoted by an iridium complex combined with Lewis acid and phosphite. Thus, terminal alkynes reacted with water or alcohols to give ketones or ketals, respectively, in good to excellent yields. α,ω-Diyne like 1,7-octadiyne was converted into 1-(2-methyl-cyclopent-1-enyl)ethanone through the intramoleculer aldol condensation of the resulting 2,7-octanedione induced by Lewis acid.
A Novel Hetero-Diels-Alder Approach towards Perhydro Quinolinones Bearing an Angular Methyl Group
Stanetty, Peter,Mihovilovic, Marko D.,Mereiter, Kurt,Voellenkle, Horst,Renz, Franz
, p. 875 - 894 (2007/10/03)
The title compounds 9-11 were synthesized by a hetero Diels-Alder reaction using the sterically demanding diene 2 as a new building block. The effect of commonly used Lewis acids and the substitution pattern of various imines 5 on both the mechanism and t
Use of a Sacrificial Aluminum Anode in the Acylation of Some Olefins
Vukicevic, Rastko D.,Joksovic, Ljubinka,Konstantinovic, Stanimir,Markovic, Zoran,Mihailovic, Mihailo Lj.
, p. 899 - 904 (2007/10/03)
The acylation of some alicyclic and aliphatic alkenes by the electrochemical generation of a catalyst using a sacrificial aluminum anode was investigated. Substrates were electrolyzed in a dichloromethane solution of an appropriate electrolyte (tetraalkylammonium salts) in the presence of an acylating agent (acetyl chloride or anhydride). Thus, unsubstituted cycloalkenes, namely cyclohexene and cycloheptene, gave by that reaction conjugated ketones, i.e. the corresponding 1-acetylcycloalkenes, as the only unsaturated carbonyl compounds in moderate-to-good yields. Under the same reaction conditions their 1-methyl derivatives gave mixtures of the corresponding conjugated and β,γ-unsaturated isomeric ketones in which unconjugated compounds predominate. In both cases unsaturated ketones were accompanied by different amounts of side products. Terminal aliphatic alkenes (1-hexene, 1-heptene, and 1-dodecene) afforded only conjugated a ketone with a normal skeleton, but in lower yields. The acylation of cyclohexene was studied in more detail, altering the reaction conditions by changing the reaction temperature, the supporting electrolyte, the acylating agent and the electrochemical cell. Mechanistic considerations were made on the basis of the products distribution and some theoretical calculations being made by the MOPAC program package (version 7.0).
Phosphane Alkylenes, 53. - Synthesis of α,β-Unsaturated Cycloalkanones from Bis - A Method for the Transformation of Acid Anhydrides into Carbocyclic and Heterocyclic Compounds
Bestmann, Hans Juergen,Pichl, Rainer,Zimmermann, Reiner
, p. 725 - 732 (2007/10/02)
Alkaline hydrolysis of bis 3 leads to 2-cycloalken-1-ones 6.Intramolecular Wittig reaction of an intermediately formed monoacyl ylide 4 and intramolecular aldol condensation of a diketone 5, resulting from hydrolysis of both ylide functions, are discussed as possible reaction mechanisms.The oxidation of 3 with H2O2 * Ph3PO yields 7- and 8-membered 2-cycloalkene-1,4-diones 12, presumely via mono ylides 11 carrying an aldehyde group in the ω-position.The reactions of 3 with aldehydes (molar ratio 1:1) lead to the formation of mono Wittig compounds 15 which can cyclize affording 5- and 6-membered 3-alkenyl-2-cycloalken-1-ones 16.Since the ylides 3 are easily available from acid anhydrides the reaction sequences represent versatile approaches for the transformation of acid anhydrides into 2-cycloalken-1-ones. Key Words: Phosphonium ylides / Wittig reactions, intramolecular / Aldol condensations, intramolecular / 2-Cycloalken-1-ones / 2-Cycloalken-1,4-diones
Synthesis with Organoboranes; 4. Transformation of Olefins into Homoallylic Alcohols, β,γ- and α,β-Unsaturated Ketones via Allylic Diethylboranes
Zaidlewicz, Marek
, p. 701 - 703 (2007/10/02)
Allylic diethylboranes are obtained from 1-methylcycloalkenes and 2-alkenes, respectively, via metalation with trimethylsilylmethylpotassium (generated in situ from bis(trimethylsilylmethyl)mercury and potassium sand) and subsequent reaction with chlorodiethylborane.The allylic boranes react diastereoselectively with aldehydes to give homoallylic alcohols.The alcohols are oxidized with pyridinium dichromate to β,γ-unsaturated ketones, which in turn are isomerized with aluminum oxide to conjugated ketones.The transformation provides access to 2-methylene-1-acylcycloalkanes, 3-acyl-1-alkenes and 3-acyl-2-alkenes not readily available by Friedel-Crafts acylation of olefins.
ALUMINUM OXIDE CATALYZED ISOMERIZATION OF ACYLATED CYCLOALKENES
Hudlicky, T.,Srnak, T.
, p. 3351 - 3354 (2007/10/02)
A homologous series of cyclic olefins and their corresponding 1-methyl derivatives were acylated using acetic anhydride/zinc chloride system.The resulting mixtures were, after appropriate analysis, isomerized quantitatively to the conjugated enones by adsorption on neutral alumina.A detailed, general experimental procedure is given.
