Nickel-Catalyzed Regioselective Hydroalkynylation of Styrenes: Improved Catalyst System, Reaction Scope, and Mechanism
摘要:
Addition of the sp-C-H bond of triisopropylsilylacetylene to the carbon-carbon double bonds of styrenes bearing functional groups proceeded efficiently at room temperature in the presence of 3 mol % of Ni(cod)(2) with a PMePh2 ligand. Use of 2-deuteriotriisopropylsilylacetylene in the hydroalkynylation of styrenes resulted in regioselective incorporation of deuterium into the beta-positions of recovered styrenes, along with its regioselective introduction into the product's methyl group.
Ir-Catalyzed Regio- and Enantioselective Hydroalkynylation of Trisubstituted Alkene to Access All-Carbon Quaternary Stereocenters
作者:Su-Lei Zhang、Wen-Wen Zhang、Bi-Jie Li
DOI:10.1021/jacs.1c04493
日期:2021.6.30
substrate-directed, iridium-catalyzed enantioselective hydroalkynylations of trisubstituted alkenes to form an acyclic all-carbon quaternary stereocenter β to a nitrogen atom. The hydroalkynylation of enamide occurred with unconventional selectivity, favoring the more hindered reaction site. Homopropargyl amides with β-stereocenters were prepared in high regio- and enantioselectivities. Combined experimental and
Atom-Economical Cross-Coupling of Internal and Terminal Alkynes to Access 1,3-Enynes
作者:Mingyu Liu、Tianhua Tang、Omar Apolinar、Rei Matsuura、Carl A. Busacca、Bo Qu、Daniel R. Fandrick、Olga V. Zatolochnaya、Chris H. Senanayake、Jinhua J. Song、Keary M. Engle
DOI:10.1021/jacs.0c12565
日期:2021.3.17
synthesizing 1,3-enynes without prefunctionalized building blocks. In this transformation several classes of unactivated internal acceptor alkynes can be coupled with terminal donor alkynes to deliver 1,3-enynes in a highly regio- and stereoselective manner. The scope of compatible acceptor alkynes includes propargyl alcohols, (homo)propargyl amine derivatives, and (homo)propargyl carboxamides. This method is
Construction of Acyclic Quaternary Carbon Stereocenters by Catalytic Asymmetric Hydroalkynylation of Unactivated Alkenes
作者:Zi-Xuan Wang、Bi-Jie Li
DOI:10.1021/jacs.9b03027
日期:2019.6.12
stereocenters. We describe here an iridium catalyzed asymmetric hydroalkynylation of nonactivated trisubstituted alkene. The hydroalkynylation of β,γ-unsaturated amides occurs with high regio- and enantioselectivities to afford alkyne-substituted acyclic quaternary carbon stereocenters. Computational and experimental data suggest that the enantioselectivity is not only determined by the facial selectivity
Asymmetric addition of (triisopropylsilyl)acetylene to α,β,γ,δ-unsaturated carbonyl compounds took place in the presence of a cobalt/Duphos catalyst to give the 1,6-addition products in high yields with high regio- and enantioselectivity.
Iridium-catalyzed, ligand-controlled directed alkynylation and alkenylation of arenes with terminal alkynes
作者:Xin Sun、Wei Zhao、Bi-Jie Li
DOI:10.1039/c9cc08735d
日期:——
choice of a suitable ligand, a C-H alkynylation or alkenylation product could be obtained selectively. The directed C-H alkynylation proceeded without the need for an external oxidant, while the directed C-H alkenylation likely involves an unusual vinylidene mechanism. This divergent reactivity provides access to both alkynylation and alkenylation products from the same set of starting materials.