Cross-Metathesis Assisted by Microwave Irradiation
摘要:
[GRAPHICS]Microwave irradiation effectively accelerates cross-coupling metathesis reactions between deactivated olefins. Reactions have been carried out with the phosphine-free Hoveyda-Grubbs catalyst and the "second generation Grubbs' catalyst." While there have been reports that a "microwave effect" is observed in various transformations, the accelerations we observe are due to the efficient and rapid heating and increased pressure in the microwave apparatus.
Cross-Metathesis Assisted by Microwave Irradiation
作者:Frédéric C. Bargiggia、William V. Murray
DOI:10.1021/jo0514624
日期:2005.11.1
[GRAPHICS]Microwave irradiation effectively accelerates cross-coupling metathesis reactions between deactivated olefins. Reactions have been carried out with the phosphine-free Hoveyda-Grubbs catalyst and the "second generation Grubbs' catalyst." While there have been reports that a "microwave effect" is observed in various transformations, the accelerations we observe are due to the efficient and rapid heating and increased pressure in the microwave apparatus.
Enantioselective N‐Heterocyclic Carbene Catalysis via the Dienyl Acyl Azolium
作者:Rachel M. Gillard、Jared E. M. Fernando、David W. Lupton
DOI:10.1002/anie.201712604
日期:2018.4.16
Herein we report the enantioselective N‐heterocycliccarbenecatalyzed (4+2) annulation of the dienyl acyl azolium with enolates. The reaction exploits readily accessible acyl fluorides and TMS enol ethers to give a range of highly enantio‐ and diastereo‐enriched cyclohexenes (most >97:3 er and >20:1 dr). The reaction was found to require high nucleophilicity NHC catalysts with mechanistic studies