Intermolecular Hydroacylation: High Activity Rhodium Catalysts Containing Small-Bite-Angle Diphosphine Ligands
作者:Adrian B. Chaplin、Joel F. Hooper、Andrew S. Weller、Michael C. Willis
DOI:10.1021/ja211649a
日期:2012.3.14
rhodium complexes containing methylene bridged diphosphine ligands, viz. [Rh(C(6)H(5)F)(R(2)PCH(2)PR'(2))][BAr(F)(4)] (R, R' = (t)Bu or Cy; Ar(F) = C(6)H(3)-3,5-(CF(3))(2)), are shown to be practical and very efficient precatalysts for the intermolecularhydroacylation of a wide variety of unactivated alkenes and alkynes with β-S-substitutedaldehydes. Intermediate acyl hydride complexes [Rh((t)Bu(2)PCH
Well-Defined and Robust Rhodium Catalysts for the Hydroacylation of Terminal and Internal Alkenes
作者:Amparo Prades、Maitane Fernández、Sebastian D. Pike、Michael C. Willis、Andrew S. Weller
DOI:10.1002/anie.201503208
日期:2015.7.13
A Rh‐catalyst system based on the asymmetric ligand tBu2PCH2P(o‐C6H4OMe)2 is reported that allows for the hydroacylation of challenging internalalkenes with β‐substituted aldehydes. Mechanistic studies point to the stabilizing role of both excess alkene and the OMe‐group.
据报道,基于不对称配体t Bu 2 PCH 2 P( o -C 6 H 4 OMe) 2的 Rh 催化剂系统可以用 β 取代醛对具有挑战性的内烯烃进行加氢酰化。机理研究指出了过量烯烃和 OMe 基团的稳定作用。
Intermolecular Alkene and Alkyne Hydroacylation with β-S-Substituted Aldehydes: Mechanistic Insight into the Role of a Hemilabile P-O-P Ligand
作者:Gemma L. Moxham、Helen Randell-Sly、Simon K. Brayshaw、Andrew S. Weller、Michael C. Willis
DOI:10.1002/chem.200800738
日期:2008.9.19
complexes [Rh(CH(2)CH(2)CO(2)Me)(COC(2)H(4)SMe)(DPEphos)][X] and [Rh(CH(2)CH(2)CO(2)Me)(COC(6)H(4)SMe)(DPEphos)][X]. In these complexes, the DPEphos ligand is now cis chelating. A model for the (unobserved) transient alkene complex that would result from addition of alkene to the acyl-hydrido complexes comes from formation of the MeCN adducts [Rh(DPEphos)(MeSC(2)H(4)CO)H(MeCN)][X] and [Rh(DPEphos)(
Aryl Methyl Sulfides as Substrates for Rhodium-Catalyzed Alkyne Carbothiolation: Arene Functionalization with Activating Group Recycling
作者:Joel F. Hooper、Adrian B. Chaplin、Carlos González-Rodríguez、Amber L. Thompson、Andrew S. Weller、Michael C. Willis
DOI:10.1021/ja2108992
日期:2012.2.15
A Rh(I)-catalyzed method for the efficient functionalization of arenes is reported. Aryl methyl sulfides are combined with terminal alkynes to deliver products of carbothiolation. The overall process results in reincorporation of the original arene functional group, a methyl sulfide, into the products as an alkenyl sulfide. The carbothiolation process can be combined with an initial Rh(I)-catalyzed alkene or alkyne hydroacylation reaction in three-component cascade sequences. The utility of the alkenyl sulfide products is also demonstrated in simple carbo- and heterocycle-forming processes. We also provide mechanistic evidence for the course of this new process.
Traceless Chelation-Controlled Rhodium-Catalyzed Intermolecular Alkene and Alkyne Hydroacylation
作者:Joel F. Hooper、Rowan D. Young、Andrew S. Weller、Michael C. Willis
DOI:10.1002/chem.201204056
日期:2013.2.25
A new functional‐group tolerant, rhodium‐catalyzed, sulfide‐reduction process is combined with rhodium‐catalyzed chelation‐controlled hydroacylation reactions to give a traceless hydroacylation protocol. Aryl‐ and alkenyl aldehydes can be combined with both alkenes, alkynes and allenes to give traceless products in high yields. A preliminary mechanistic proposal is also presented.