182809-45-6Relevant academic research and scientific papers
Direct β- and γ-C(sp3)?H Alkynylation of Free Carboxylic Acids**
Ghiringhelli, Francesca,Ghosh, Kiron Kumar,Uttry, Alexander,van Gemmeren, Manuel
supporting information, p. 23127 - 23131 (2020/10/15)
In this study we report the identification of a novel class of ligands for palladium-catalyzed C(sp3)?H activation that enables the direct alkynylation of free carboxylic acid substrates. In contrast to previous synthetic methods, no introduction/removal of an exogenous directing group is required. A broad scope of acids including both α-quaternary and challenging α-non-quaternary can be used as substrates. Additionally, the alkynylation in the distal γ-position is reported. Finally, this study encompasses preliminary findings on an enantioselective variant of the title transformation as well as synthetic applications of the products obtained.
Stoichiometric and Catalytic C?C and C?H Bond Formation with B(C6F5)3 via Cationic Intermediates
Soltani, Yashar,Wilkins, Lewis C.,Melen, Rebecca L.
supporting information, p. 11995 - 11999 (2017/09/20)
This work showcases a new catalytic cyclization reaction using a highly Lewis acidic borane with concomitant C?H or C?C bond formation. The activation of alkyne-containing substrates with B(C6F5)3 enabled the first catalytic intramolecular cyclizations of carboxylic acid substrates using this Lewis acid. In addition, intramolecular cyclizations of esters enable C?C bond formation as catalytic B(C6F5)3 can be used to effect formal 1,5-alkyl migrations from the ester functional groups to unsaturated carbon–carbon frameworks. This metal-free method was used for the catalytic formation of complex dihydropyrones and isocoumarins in very good yields under relatively mild conditions with excellent atom efficiency.
Bismuth-catalyzed intramolecular carbo-oxycarbonylation of 3-alkynyl esters
Komeyama, Kimihiro,Takahashi, Keita,Takaki, Ken
supporting information; experimental part, p. 5119 - 5122 (2009/05/30)
(Chemical Equation Presented) Borderline metal complexes, especially Bi(OTf)3, efficiently catalyze the carbo-oxycarbonylation of alkynyl esters to form multisubstituted lactones in moderate to high yields.
Lewis acid-mediated intramolecular addition of silyl enol ethers to internal unactivated alkynes
Imamura, Ken-Ichiro,Yoshikawa, Eiji,Gevorgyan, Vladimir,Sudo, Tomoko,Asao, Naoki,Yamamoto, Yoshinori
, p. 1624 - 1631 (2007/10/03)
The EtAlCl2-mediated intramolecular addition of silyl enol ethers to both terminal and internal unactivated alkynes, bearing alkyl and phenyl susbstituents at the alkyne moiety, gave mono- and bicyclic β,γ-unsaturated ketones in good to excelle
