4168-01-8Relevant articles and documents
Die Acylierung von Acetylenen mit β,γ-ungesaettigten Saeurechloriden. Eine neue Synthese von 5-substituierten 2-Cyclopentenonen
Karpf, Martin
, p. 73 - 85 (1984)
The acylation of acetylenes with α,α-disubstituted, β,γ-unsaturated acid chlorides under Friedel-Crafts-type conditions leads to 5-substituted 2-cyclopentenones.Phenols are formed with β,γ-unsaturated acid chlorides bearing at least one α-H-atom.These transformations are explained by the intramolecular cyclization of the initially formed vinyl cation, which, in the cases of α,α-disubstituted acid chlorides, is formed by ring contraction.The reaction leading to 2-cyclopentenones is applied to the syntesis of some spirodeca-2,6-dienones.
A Light/Ketone/Copper System for Carboxylation of Allylic C-H Bonds of Alkenes with CO2
Ishida, Naoki,Masuda, Yusuke,Uemoto, Sho,Murakami, Masahiro
supporting information, p. 6524 - 6527 (2016/05/02)
A photo-induced carboxylation reaction of allylic C-H bonds of simple alkenes with CO2 is prompted by means of a ketone and a copper complex. The unique carboxylation reaction proceeds through a sequence of an endergonic photoreaction of ketones with alkenes forming homoallyl alcohol intermediates and a thermal copper-catalyzed allyl transfer reaction from the homoallyl alcohols to CO2 through C-C bond cleavage. An allylic C-H bond of simple alkenes is carboxylated with CO2 in the presence of a substoichiometric amount of a ketone and a catalytic amount of a copper complex under UV irradiation (see scheme).
Metal-free oxyaminations of alkenes using hydroxamic acids
Schmidt, Valerie A.,Alexanian, Erik J.
supporting information; scheme or table, p. 11402 - 11405 (2011/09/16)
A radical-mediated approach to metal-free alkene oxyamination is described. This method capitalizes on the unique reactivity of the amidoxyl radical in alkene additions to furnish a general difunctionalization using simple diisopropyl azodicarboxylate (DIAD) as a radical trap. This protocol capitalizes on the intramolecular nature of the process, providing single regioisomers in all cases. Difunctionalizations of cyclic alkenes provide trans oxyamination products inaccessible using current methods with high levels of stereoselectivity, complementing cis-selective oxyamination processes.
Catalytic hydromagnesation of di- and polymethyl-substituted 1,3-butadienes
Viktorov,Zubritskii
, p. 1755 - 1765 (2007/10/03)
Hydromagnesation of di- and polymethyl-substituted 1,3-butadienes with alkylmagnesium halides in the presence of Ni(PPh3)2Cl2 and NiPy4Cl2 was studied.