960305-76-4Relevant academic research and scientific papers
An efficient method for retro-Claisen-type C-C bond cleavage of diketones with tropylium catalyst
Hussein,Huynh,Hommelsheim,Koenigs,Nguyen
supporting information, p. 12970 - 12973 (2018/11/23)
The retro-Claisen reaction is frequently used in organic synthesis to access ester derivatives from 1,3-dicarbonyl precursors. The C-C bond cleavage in this reaction is usually promoted by a number of transition-metal Lewis acid catalysts or organic Br?nsted acids/bases. Herein we report a new convenient and efficient method utilizing the tropylium ion as a mild and environmentally friendly organocatalyst to mediate retro-Claisen-type reactions. Using this method, a range of synthetically valuable substances can be accessed via solvolysis of 1,3-dicarbonyl compounds.
Indium-catalyzed synthesis of keto esters from cyclic 1,3-diketones and alcohols and application to the synthesis of seratrodast
Kuninobu, Yoichiro,Kawata, Atsushi,Noborio, Taihei,Yamamoto, Syun-Ichi,Matsuki, Takashi,Takata, Kazumi,Takai, Kazuhiko
experimental part, p. 941 - 945 (2010/07/07)
Esterification reactions from cyclic 1,3-diketones and alcohols are carried out in the presence of several Lewis acids. In particular, indium(III) triflate, In(OTf)3, iron(III) triflate, Fe-(OTf)3, copper(II) triflate, Cu(OTf)2, and silver(I) triflate, AgOTf, show high catalytic activities. These reactions proceed through the carbon-carbon bond cleavage by a retro-aldol reaction and were found to be highly regioselective even in the presence of other functional groups. This type of reaction can also be applied to the preparation of the keto esters during the synthesis of seratrodast, which is an antiasthmatic and eicosanoid antagonist.
Retro-claisen condensation with FeIII as catalyst under solvent-free conditions
Rao, Chitturi Bhujanga,Rao, Dasireddi Chandra,Babu, Dokuburra Chanti,Venkateswarlu, Yenamandra
supporting information; experimental part, p. 2855 - 2859 (2010/08/05)
An iron(III) salt catalyzed retro-Claisen condensation between an alcohol and a 1,3-diketone was investigated. The mechanism involves the formation of a metal-induced sixmembered cyclic transition state and cleavage of the C sp2-Csp3 bond. Regioselective esterification and one-pot couversion of silyl ethers into esters with good yields was observed. Simple reaction conditions, high yields, and broad scope of the reaction illustrate the good synthetic utility of this method.
Indium-catalyzed retro-claisen condensation
Kawata, Atsushi,Takata, Kazumi,Kuninobu, Yoichiro,Takai, Kazuhiko
, p. 7793 - 7795 (2008/09/18)
(Chemical Equation Presented) Retro-aldol reaction: Indium-catalyzed reaction of a 1,3-diketone with an alcohol proceeds under solvent-free conditions by nucleophilic attack of the alcohol on a carbonyl group of the 1,3-diketone and carbon-carbon bond cleavage by a retro-Claisen condensation to give an ester in high yield (see scheme). Using water and an amine as nucleophiles instead of an alcohol gave the corresponding carboxylic acid and amide.
