3024-05-3Relevant articles and documents
Cobalt-Catalyzed Allylic C(sp3)-H Carboxylation with CO2
Michigami, Kenichi,Mita, Tsuyoshi,Sato, Yoshihiro
, p. 6094 - 6097 (2017/05/08)
Catalytic carboxylation of the allylic C(sp3)-H bond of terminal alkenes with CO2 was developed with the aid of a Co/Xantphos complex. A wide range of allylarenes and 1,4-dienes were successfully transformed into the linear styrylacetic acid and hexa-3,5-dienoic acid derivatives in moderate to high yields, with excellent regioselectivity. The carboxylation showed remarkable functional group tolerability, so that selective addition to CO2 occurred in the presence of other carbonyl groups such as amide, ester, and ketone. Since styrylacetic acid derivatives can be readily converted into optically active γ-butyrolactones through Sharpless asymmetric dihydroxylation, this allylic C(sp3)-H carboxylation showcases a facile synthesis of γ-butyrolactones from simple allylarenes via short steps.
PROCESS FOR THE PREPARATION OF DICARBOXYLIC ACIDS OR DICARBOXYLIC ACID ESTERS BY METATHESIS
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, (2011/10/05)
The present invention relates to a process for the preparation of dicarboxylic acids or dicarboxylic acid esters comprising the following process steps: A1 provision of at least the following reactants: a1 - a first aliphatic compound having 5 to 40 carbon atoms with in each case at least one functional group of the general formula (I) and (II), wherein R1 is a saturated or unsaturated aliphatic group having 2 to 20, preferably 4 to 16 and particularly preferably 6 to 12 carbon atoms and R2 is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, preferably having 1 to 5 carbon atoms and particularly preferably having 1, 2 or 3 carbon atoms formula (I) and (II) and a2 at least one further aliphatic compound which differs from the first aliphatic compound, chosen from the group consisting of a2a a compound of the general formula (III) in which n is chosen from 1, 2, 3, 4 and 5; a2b a compound of the general formula (IV) in which R3 is a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, preferably having 1 to 5 carbon atoms and particularly preferably having 1, 2 or 3 carbon atoms and R4 and R5 independently of each other are a saturated alkylene group having 1 to 14 carbon atoms, preferably having 1 to 10 carbon atoms and very particularly preferably 1 to 5 carbon atoms; A2 provision of at least one organometallic catalyst based on ruthenium; A3 bringing into contact of the reactants and the catalyst to obtain a product mixture and the catalyst; A4 separating off of the catalyst; A5 optionally division of the product mixture into products Pi, i being a natural number, and the reactants which remain; the process being a metathesis reaction, and the dicarboxylic acid obtainable therefrom and the dicarboxylic acid ester obtainable therefrom, a process for the preparation of a polymer and the polymer obtainable by this process.