Sulfonated N-Heterocyclic Carbenes for Pd-Catalyzed Sonogashira and Suzuki-Miyaura Coupling in Aqueous Solvents
作者:Sutapa Roy、Herbert Plenio
DOI:10.1002/adsc.200900886
日期:——
of the respective disulfonated N‐heterocyclic carbene (NHC) precursors in reasonable yields (46–77%). Water‐soluble palladium catalyst complexes, in situ obtained from the respective sulfonated imidazolinium salt, sodium tetrachloropalladate (Na2PdCl4) and potassium hydroxide (KOH) in water, were successfully applied in the copper‐free Sonogashiracoupling reaction in isopropyl alcohol/water mixtures
Multi-Metal-Catalyzed Oxidative Radical Alkynylation with Terminal Alkynes: A New Strategy for C(sp<sup>3</sup>)–C(sp) Bond Formation
作者:Shan Tang、Yichang Liu、Xinlong Gao、Pan Wang、Pengfei Huang、Aiwen Lei
DOI:10.1021/jacs.8b02745
日期:2018.5.9
for C(sp3)-C(sp) cross-coupling with terminalalkynes has been developed by using a multi-metal-catalyzed reaction strategy. Alkyl radicals generated from different approaches are able to couple with terminalalkynes by judicious selection of the catalyst combination. This reaction protocol offers an efficient alternative approach for the synthesis of substituted alkynes from terminalalkynes besides
Visible light promoted coupling of alkynyl bromides and Hantzsch esters for the synthesis of internal alkynes
作者:Zhi-Yong Song、Chun-Lin Zhang、Song Ye
DOI:10.1039/c8ob02912a
日期:——
A metal-free visible light promoted C(sp3)–C(sp) coupling reaction of alkynyl bromides and Hantzsch esters was developed, giving internal alkynes with primary, secondary, tertiary alkyl or other functional groups in good to high yields.
Regio- and Stereoselective Chlorocyanation of Alkynes
作者:Alejandro G. Barrado、Adam Zieliński、Richard Goddard、Manuel Alcarazo
DOI:10.1002/anie.201705851
日期:2017.10.16
A variety of terminal and internal alkynes were converted regio‐ and stereoselectively into (Z)‐3‐chloroacrylonitriles by treatment with BCl3 in the presence of stoichiometric amounts of imidazolium thiocyanates. These products could be readily functionalized to provide useful building blocks, thus demonstrating the synthetic value of the method. Preliminary mechanistic studies suggest initial activation
Rh<sup>I</sup>/Rh<sup>III</sup> catalyst-controlled divergent aryl/heteroaryl C–H bond functionalization of picolinamides with alkynes
作者:Ángel Manu Martínez、Javier Echavarren、Inés Alonso、Nuria Rodríguez、Ramón Gómez Arrayás、Juan C. Carretero
DOI:10.1039/c5sc01885d
日期:——
Switchable site-selectivity through catalyst control is achieved in the direct functionalization of picolinamides that contain two distinct C–H sites to construct diverse scaffolds from the same starting material.