16000-14-9Relevant academic research and scientific papers
Gold-Catalyzed Cycloisomerizations of Functionalyzed Cyclopropyl Alkynes: the Cases of Carboxamides and Alcohols
Fernández-García, Jesús M.,Garro, Hugo A.,Fernández-García, Laura,García-García, Patricia,Fernández-Rodríguez, Manuel A.,Merino, Isabel,Aguilar, Enrique
supporting information, p. 3035 - 3051 (2017/09/09)
Push-pull alkynylcyclopropane derivatives are claimed as suitable and active substrates for gold-catalyzed transformations. Thus, 2(3H)-azepinones can be readily prepared from alkynylcyclopropanecarboxamides through a nucleophilic addition/cyclopropane ring-opening cascade process and, in this manuscript, the scope and the limitations of such reaction sequence are reported. The cascade reaction is general and occurs with complete regio- and quimioselection to form the seven-membered heterocycles with the exception of primary alkyl-substituted alkynylcyclopropanecarboxamides that render 4-methoxy-6-oxo-4-enenitriles in moderate yields. Additionally, less activated alkynylcyclopropylmethanols undergo regioselective cycloisomerization at low temperature leading to oxabicyclo[4.1.0]heptanes. Notably, the cyclopropane ring opening of these adducts takes place under thermal conditions to form dihydropyranones. (Figure presented.).
Bronsted acid catalyzed cycloisomerizations of 5,2-enyne-1-ones: Highly regioselective synthesis of 2,3-dihydro-4H-pyran-4-ones
Yang, Fang,Ji, Ke-Gong,Zhao, Shu-Chun,Ali, Shaukat,Ye, Yu-Ying,Liu, Xue-Yuan,Liang, Yong-Min
, p. 6470 - 6474 (2012/06/15)
Dual-action catalyst: A Bronsted acid catalyzed regioselective cycloisomerization was found to be highly effective for the preparation of structurally diverse 2,3-dihydro-4H-pyran-4-ones in a 6-exo-trig manner from the corresponding 5,2-enyne-1-ones. In t
2,3-Dihydro-4H-pyran-4-ones and 2,3-dihydro-4-pyridinones by cyclizations of α,β-unsaturated 1,3-diketones
MacDonald, Franklyn K.,Burnell, D. Jean
experimental part, p. 6973 - 6979 (2009/12/06)
(Chemical Equation Presented) A variety of α,β-unsaturated 1,3-diketones cyclize to 2,3-dihydro-4H-pyran-4-ones in an acidic aqueous medium, with exceptions being α,β-unsaturated 1,3-diketones in which the β carbon is substituted by a phenyl group. Additi
