Alcohols react with arenes in the presence of cationic iron(III) porphyrin catalyst. The reaction involves the formation of the C–C bond via dehydration, which is formal Lewis acid catalyzed Friedel–Craftsreaction.
Regioselective Iron‐Catalysed Cross‐Coupling Reaction of Aryl Propargylic Bromides and Aryl Grignard Reagents
作者:Inés Manjón‐Mata、M. Teresa Quirós、Elena Buñuel、Diego J. Cárdenas
DOI:10.1002/adsc.201901203
日期:2020.1.7
An iron‐catalysed Kumada‐type cross‐coupling reaction between aryl substituted propargylic bromides and arylmagnesium reagents has been developed. Propargylic coupling products were the main or only outcome, and propargyl/allene regioselectivity was shown to depend on the electronic nature of the substituents on the triple bond of the substrate and on the arylmagnesium halide. Best selectivities were
Electrophilic chemistry of propargylic alcohols in imidazolium ionic liquids: Propargylation of arenes and synthesis of propargylic ethers catalyzed by metallic triflates [Bi(OTf)3, Sc(OTf)3, Yb(OTf)3], TfOH, or B(C6F5)3
作者:Gopalakrishnan Aridoss、Viorel D. Sarca、James F. Ponder Jr、Jessica Crowe、Kenneth K. Laali
DOI:10.1039/c0ob00872a
日期:——
formed. Steric influence of the propargylic moiety on substrate selectivity is reflected in the lack of ortho propargylation for phenol and ethylbenzene by using propargylic alcohol Ia, and notable formation of the ortho isomer employing alcohol Ib. In the later case paraselectivity could be increased by running the reaction at r. t. for 10 h. The Bi(OTf)3-catalyzed reaction of 1,3-dimethoxybenzene with
Synthesis and Functionalization of Allenes by Direct Pd‐Catalyzed Organolithium Cross‐Coupling
作者:Jaime Mateos‐Gil、Anirban Mondal、Marta Castiñeira Reis、Ben L. Feringa
DOI:10.1002/anie.201913132
日期:2020.5.11
A palladium-catalyzed cross-coupling between in situ generated allenyl/propargyl-lithium species and arylbromides to yield highly functionalized allenes is reported. The direct and selective formation of allenic products preventing the corresponding isomeric propargylic product is accomplished by the choice of SPhos or XPhos based Pd catalysts. The methodology avoids the prior transmetalation to other
SOMOphilic Alkynylation of Unreactive Alkenes Enabled by Iron-Catalyzed Hydrogen Atom Transfer
作者:Binlin Zhao、Tianxiang Zhu、Mengtao Ma、Zhuangzhi Shi
DOI:10.3390/molecules27010033
日期:——
We report an efficient and practical iron-catalyzed hydrogen atom transfer protocol for assembling acetylenic motifs into functional alkenes. Diversities of internal alkynes could be obtained from readily available alkenes and acetylenic sulfones with excellent Markovnikov selectivity. An iron hydride hydrogen atom transfer catalytic cycle was described to clarify the mechanism of this reaction.