General Zinc-Catalyzed Conia-Ene Reactions of 1,3-Dicarbonyl Compounds with Alkynes Including the Classically Challenging Substrates under Neat Conditions
作者:Chen-Liang Deng、Ren-Jie Song、Yi-Lin Liu、Jin-Heng Li
DOI:10.1002/adsc.200900588
日期:2009.12
products has been developed by zinc-catalyzed intramolecular Conia-enereactions of 1,3-dicarbonylcompounds with alkynes. This new route allows a wide range of dicarbonyl compounds, including the classicallychallenging 1,3-diesters and N,N′-disubstituted 1,3-keto amides, to be used for the Conia-enereaction with inexpensive zinc chloride (ZnCl2) underneatconditions.
Catalytic electronic activation as a tool for the addition of stabilised nucleophiles to allylic alcohols
作者:Phillip J. Black、Michael G. Edwards、Jonathan M.J. Williams
DOI:10.1016/j.tet.2004.10.009
日期:2005.1
describes the activation of 2-cyclohexen-1-ol (1) and 2-cyclopenten-1-ol (11) through the use of aluminium-catalysed transfer hydrogenation. The electronically activated substrates are demonstrated to undergo facile conjugate addition and, when the alcohol functional group is subsequently restored in a one-pot procedure, this leads to an indirect addition of nucleophiles to allylic alcohols. This novel
A straightforward N‐heterocycliccarbene (NHC)/LiCl‐mediated synthesis of dihydropyranones from α,β‐unsaturated carboxylic acids and 1,3‐dicarbonyl compounds was realized through the in situ activation strategy. The key advantages of this protocol include ready availability and high stability of starting materials, good yields, and excellent enantioselectivity.
Diastereo‐ and Enantioselective Inverse‐Electron‐Demand Diels–Alder Cycloaddition between 2‐Pyrones and Acyclic Enol Ethers
作者:Guanghao Huang、Régis Guillot、Cyrille Kouklovsky、Boris Maryasin、Aurélien de la Torre
DOI:10.1002/anie.202208185
日期:2022.10.17
The inverse-electron-demand Diels–Alder cycloaddition between 2-pyrones and acyclic enolethers was investigated. Bridged bicyclic lactones were obtained diastereo- and enantioselectively and converted into synthetically relevant polysubstituted enantioenriched cyclohexene and cyclohexadiene derivatives. Mechanistic evidence as well as DFT calculations point towards a stepwise mechanism.
Alkyne Polymers from Stable Butatriene Homologues: Controlled Radical Polymerization of Vinylidenecyclopropanes
作者:Bin Wu、Qian-Jun Ding、Zheng-Lin Wang、Rong Zhu
DOI:10.1021/jacs.2c12220
日期:2023.2.1
Controlledpolymerization of cumulenic monomers represents a promising yet underdeveloped strategy toward well-defined alkyne polymers. Here we report a stereoelectronic effect-inspired approach using simple vinylidenecyclopropanes (VDCPs) as butatriene homologues in controlledradical ring-opening polymerizations. While being thermally stable, VDCPs mimic butatrienes via conjugation of the cyclopropane