Nickel-Catalyzed Sonogashira C(sp)–C(sp<sup>2</sup>) Coupling through Visible-Light Sensitization
作者:Da-Liang Zhu、Ruijie Xu、Qi Wu、Hai-Yan Li、Jian-Ping Lang、Hong-Xi Li
DOI:10.1021/acs.joc.0c01177
日期:2020.7.17
efficient method for visible-light-initiated, nickel-catalyzed Sonogashira C(sp)–C(sp2) coupling has been developed via an energy-transfer mode. Thioxanthen-9-one as a photosensitizer could significantly accelerate the arylation of alkynes with a wide range of (hetero)aryl halides in high yields. The cross-couplingreaction undergoes the stepwise oxidative addition of an arylhalide to nickel(0), transmetalation
An efficient and inexpensive catalytic system using a readily available CuCl/PPh3 combination for the catalytic cross-coupling reactions of alkynylsilanes with a variety of aryl iodides affords uns...
degrees C under an aerobicconditions smoothly undergoes homo-coupling to give the corresponding symmetrical 1,3-butadiynes in 70-99% yields. In addition, (arylethynyl)trimethylsilanes are found to couple with aryl triflates and chlorides in the presence of Cu(I)/Pd(0) (10 mol %/5 or 10 mol %) cocatalyst system to give the corresponding diarylethynes in 49-99% yields. The cross-coupling reaction is
Alkynylsilanes reacted with aryl or alkenyl triflates in the presence of 5 mol% of Pd(PPh3)4 and 10 mol% of CuCl in DMF to give the corresponding cross-coupling, namely “sila”-Sonogashira-Hagihara coupling, products in good to excellent yields. The present reaction is highly effective for one-pot synthesis of unsymmetrical diarylacetylenes.
Synthesis of Unsymmetrical Diarylethynes by Pd(0)/Cu(I)-cocatalyzed Sila-Sonogashira–Hagihara Coupling Reactions of Alkynylsilanes with Aryl Tosylates or Mesylates
Palladium/copper-cocatalyzed cross-coupling reactions of alkynylsilanes with aryl tosylates or mesylates afforded the corresponding unsymmetrical diarylethynes in moderate to good yields. The optimized reaction conditions to afford higher yields of cross-coupled products were found to be 5 mol % of [PdCl2(bpy)], 15 mol % of BrettPhos, and 10 mol % of CuICl in DMF as a solvent.