Alkynes react with organoborons under a CO atmosphere in the presence of a rhodium(I) catalyst to afford mainly 5-aryl-2(5H)-furanones, α,β-unsaturated ketones, and indanones. The product selectivity can be tuned by modifying the reaction conditions.
The first cross-coupling reaction of thermally stable titanium(II)–alkyne complexes with aryl iodides in the presence of a catalytic amount of Ni(cod)2 is presented.
Nickel-Catalyzed Hydroarylation of Alkynes under Reductive Conditions with Aryl Bromides and Water
作者:E. Ryan Barber、Hannah M. Hynds、Claudia P. Stephens、Holli E. Lemons、Emily T. Fredrickson、Dale J. Wilger
DOI:10.1021/acs.joc.9b01556
日期:2019.9.20
coupling reaction utilizes commercially available alkynes and aryl bromides, along with water and Zn. An air-stable and easily synthesized Ni(II) precatalyst is the only entity used in the reaction that is not commercially available. This reductive cross-coupling reaction displays a fairly unusual anti selectivity when aryl bromides with ortho substituents are used. In addition to optimization data
Pd-catalyzed Heck reactions of aryl bromides with 1,2-diarylethenes
作者:Jones Limberger、Silvia Poersch、Adriano L Monteiro
DOI:10.1590/s0103-50532011000700026
日期:——
A catalytic system composed of Pd(OAc)(2) and P(o-tol)(3) was found to be effective for the Heck reaction of aryl bromides with diarylethylenes. Using K(2)CO(3) as a base and DMF as a solvent, trisubstituted olefins were obtained in good to excellent yields. Aryl bromides containing an electron-withdrawing group in para position were less reactive for the Heck coupling reaction and gave substantial amount of homocoupling by-product suggesting that oxidative addition is not the rate-determining step. Electron withdrawing group substituent in the para position of stilbene affects the regioselectivity of the reaction. In this case, the phenyl group from the Ph-Pd complex migrates preferentially to the same carbon of the double bond to which the phenyl is bonded. Finally, a one pot sequential double Heck arylation of styrene was performed, giving trisubstituted olefin with an overall yield of 73%.