A facile preparation of tetralins from arene-1,4-diones using titanium(IV) chloride and triethylsilane
摘要:
A facile method for the synthesis of tetralins has been described which uses various substituted phenylpentane-1,4-diones as starting material with a combination of TiCl4/Et3SiH. The synthesis involves three reactions under mild conditions. A mechanism has been proposed for the reductive cyclization through ionic hydrogenation, and titanium(IV) chloride catalyzed cyclization. (C) 2011 Elsevier Ltd. All rights reserved.
Facile synthesis of 1,4-diketones via palladium complex catalyzed isomerization of alkynediols
摘要:
Alkynediols isomerized under the catalysis of Pd2(dba)3.CHCl3 + 2n-Bu3P in acetonitrile at 80-degrees-C to give 1,4-diketones in high yields. This experimentally simple and economically synthetic method is illustrated with examples including substituents such as alkyl, alkenyl, and aryl groups. The order of reactivity of the substituents in this reaction is aryl greater-than-or-equal-to alkenyl > alkyl. Alkenyl-substituted alkynediols chemoselectively isomerized to the corresponding alpha,beta-unsaturated 1,4-diketones. The usefulness of this novel method is exemplified by the synthesis of dihydrojasmone.
1,4‐ and 1,5‐diols undergo cyclodehydration upon treatment with cationic N‐heterocyclic carbene (NHC)–IrIII complexes to give tetrahydrofurans and tetrahydropyrans, respectively. The mechanism was investigated, and a metal‐hydride‐driven pathway was proposed for all substrates, except for very electron‐rich ones. This contrasts with the well‐established classical pathways that involve nucleophilic
Copper-Catalyzed Decarboxylative Oxyalkylation of Alkynyl Carboxylic Acids: Synthesis of γ-Diketones and γ-Ketonitriles
作者:Yi Li、Jia-Qi Shang、Xiang-Xiang Wang、Wen-Jin Xia、Tao Yang、Yangchun Xin、Ya-Min Li
DOI:10.1021/acs.orglett.9b00520
日期:2019.4.5
A novel copper-catalyzed decarboxylative oxyalkylation of alkynyl carboxylic acids with ketones and alkylnitriles via direct C(sp3)–H bond functionalization to construct new C–C bonds and C–O double bonds was developed. This transformation is featured by wide functionalgroup compatibility and the use of readily available reagents, thus affording a general approach to γ-diketones and γ-ketonitriles
Stetter Reaction in Room Temperature Ionic Liquids and Application to the Synthesis of Haloperidol
作者:Siddam Anjaiah、Srivari Chandrasekhar、René Grée
DOI:10.1002/adsc.200404123
日期:2004.9
Imidazolium-type roomtemperatureionic liquids (RTILs) have been used for the Stetter reaction, affording the desired 1,4-dicarbonyl compounds in good yields. Thiazolium salts and Et3N are efficient catalysts for this reaction performed in ionic liquid. The possibility to recycle and reuse the solvent has been demonstrated, although it was not possible to recycle the thiazolium catalyst. This method
Formation of 1,4-diketones via bis-acylation of the conjugated carbon–carbon double bonds in acrylates, acrylamides, methyl vinyl ketone and styrenes with aroyl chlorides promoted by samarium metal in DMF
作者:Yongjun Liu、Yongmin Zhang
DOI:10.1016/j.tet.2003.08.038
日期:2003.10
Promoted by samarium in DMF, aroyl chlorides react readily with conjugated carbon–carbondoublebonds in acrylates, acrylamides, methyl vinyl ketone and styrenes in a bis-acylation manner. These reactions proceed smoothly under mild conditions without the need of pretreating or activating the metallic samarium, affording the corresponding 1,4-diketones in good to excellent yields.
Electroreductive crossed pinacol coupling of aromatic ketones with aliphatic ketones and aldehydes
作者:Naoki Kise、Yousuke Shiozawa、Nasuo Ueda
DOI:10.1016/j.tet.2007.04.050
日期:2007.6
The intermolecular crossed pinacol coupling of aromatic ketones with aliphatic aldehydes and ketones was effected by electroreduction in the presence of chlorotrimethylsilane. The best result was obtained using a Pb cathode in Bu4NPF6/THF. The electroreduction of aromatic 1,4-, 1,5-, and 1,6-diketones under the same conditions gave four-, five-, and six-membered 1,2-diols with trans-stereoselectivity