Palladium-Catalyzed Conversion of β,γ-Unsaturated Silyl Sulfinates into (<i>E</i>)-Alkenes: Asymmetric Synthesis of Polypropionate Fragments
作者:Xiaogen Huang、Cotinica Craita、Pierre Vogel
DOI:10.1021/jo0357622
日期:2004.6.1
At low temperature, 1-alkoxy-1,3-dienes add to sulfur dioxide activated by a Lewis or protic acid generating zwitterionic intermediates that can be quenched by enoxysilanes. The resulting β,γ-unsaturated silyl sulfinates can be desilylated by 1:1 Pd(OAc)2/PPh3 catalyst, liberating the corresponding β,γ-unsaturated sulfinic acids that undergo smooth and highly stereoselective retro-ene eliminations
Poly(fluoroalkyl acrylate)-Bound Ruthenium Carbene Complex: A Fluorous and Recyclable Catalyst for Ring-Closing Olefin Metathesis
作者:Qingwei Yao、Yiliang Zhang
DOI:10.1021/ja037394p
日期:2004.1.1
The synthesis of a fluorous olefin metathesiscatalyst derived from the Grubbs second-generation ruthenium carbene complex is described. The air stable fluorous polymer-bound ruthenium carbene complex 1 shows high reactivity in effecting the ring-closingmetathesis of a broad spectrum of diene and enyne substrates leading to the formation of di-, tri-, and tetrasubstituted cyclic olefins in minimally
Synthesis of Cyclic Sulfones by Ring-Closing Metathesis
作者:Qingwei Yao
DOI:10.1021/ol017142y
日期:2002.2.1
A general and highly efficient synthesis of cyclic sulfones based on ring-closingmetathesis has been developed. The synthetic utility of the resulting cyclic sulfones was demonstrated by their participation in stereoselective Diels-Alder reactions and transformation to cyclic dienes by the Ramberg-Bäcklund reaction.
[(NHC)(NHCewg)RuCl2(CHPh)] Complexes with Modified NHCewg Ligands for Efficient Ring-Closing Metathesis Leading to Tetrasubstituted Olefins
作者:Volodymyr Sashuk、Lars H. Peeck、Herbert Plenio
DOI:10.1002/chem.200903275
日期:2010.4.6
yield from the ruthenium precursor. To learn which one of the two NHCligands acts as the leaving group in olefinmetathesis reactions two complexes, [(FL‐NHC)(NHCewg)RuCl2(CHPh)] and [(FL‐NHCewg)(NHC)RuCl2(CHPh)], with a dansyl fluorophore (FL)‐tagged electron‐rich NHCligand (FL‐NHC) and an electron‐deficient NHCligand (FL‐NHCewg) were prepared. The fluorescence of the dansyl fluorophore is quenched
Ferrocene Redox Controlled Reversible Immobilization of Ruthenium Carbene in Ionic Liquid: A Versatile Catalyst for Ring-Closing Metathesis
作者:Guiyan Liu、Haiyan He、Jianhui Wang
DOI:10.1002/adsc.200800713
日期:2009.7
A ferrocene‐tagged rutheniumcarbene 15 that can be reversibly immobilized in an ionicliquid (IL) via the controlled oxidation and reduction of a ferrocene tag was prepared. This offers a new strategy which uses redox chemistry to controlimmobilization and to recycle both the catalyst and the IL. In this experiment, 11 recycles were performed for the ring‐closing metathesis (RCM) of a substrate using