decarbonylative Sonogashira coupling of terminalalkynes with carboxylic acids was achieved through palladium catalysis. This reaction did not use overstoichiometric oxidants, thus overcoming the homocoupling issue of terminalalkynes. Under the reaction conditions, a wide range of carboxylic acids including those bioactive ones could couple readily with various terminalalkynes, thus providing a relative general
Pyrrole Synthesis via Allylic sp<sup>3</sup> C−H Activation of Enamines Followed by Intermolecular Coupling with Unactivated Alkynes
作者:Souvik Rakshit、Frederic W. Patureau、Frank Glorius
DOI:10.1021/ja104305s
日期:2010.7.21
A conceptually novel pyrrole synthesis is reported, efficiently merging enamines and (unactivated) alkynes under oxidative conditions. In an intermolecular Rh catalyzed process, the challenging allylic sp(3) C-H activation of the enamine substrates is followed by the cyclization with the alkyne (R(3) = CO(2)R). Alternatively, in some cases (R(3) = CN), the enamine can be utilized for a vinylic sp(2)
LiHMDS-Promoted Palladium-Catalyzed Sonogashira Cross-Coupling of Aryl Fluorides with Terminal Alkynes
作者:Jingjing He、Kang Yang、Jianhong Zhao、Song Cao
DOI:10.1021/acs.orglett.9b03815
日期:2019.12.6
A highly efficient Pd-catalyzed Sonogashira coupling of various aryl fluorides with terminalalkynes in the presence of LiHMDS was developed. Both unreactive electron-rich fluoroarenes and electron-poor fluoroarenes proceeded smoothly and afforded the corresponding internalalkynes in moderate to excellent yields.
Microwave-Promoted Copper-Free Sonogashira-Hagihara Couplings of Aryl Imidazolylsulfonates in Water
作者:José F. Cívicos、Diego A. Alonso、Carmen Nájera
DOI:10.1002/adsc.201200629
日期:2013.1.14
Aryl imidazol‐1‐ylsulfonates have been efficiently cross‐coupled with aryl‐, alkyl‐, and silylacetylenes in neat water under copper‐free conditions at 110 °C assisted by microwave irradiation. Using 0.5 mol% of an oxime palladacycle as precatalyst, 2‐dicyclohexylphosphino‐2′,6′‐dimethoxybiphenyl (SPhos, 2 mol%) as ligand, hexadecyltrimethylammonium bromide (CTAB) as additive, and triethylamine (TEA)
The catalytic reactions proceed with good yields with a low catalyst loading (1 mol%) under aerobic and CuI-free conditions for Sonogashira and Heck reactions.