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)(
据报道,用于β-S-取代的醛与活化的和未活化的烯烃和炔烃的分子间加氢酰化反应的组装催化剂体系简单易行。这些催化剂促进了β-S-取代的醛与具有挑战性的底物(例如内部炔烃和1-辛烯)之间的加氢酰化反应。催化剂基于[Rh(cod)(DPEphos)] [ClO(4)](DPEphos =双(2-二苯基膦基苯基)醚,cod =环辛二烯),设计用于利用DPEphos配体的半不稳定能力稳定关键的酰基氢化物中间体以防止还原性脱羰基化,从而导致催化剂死亡。醛(邻-HCOCH(2)CH(2)SMe或邻-HCOC(6)H(4)SMe)和丙烯酸甲酯向前体丙酮络合物[Rh(丙酮)(2)(DPEphos)的化学计量添加的研究] [X] [X = closo-CB(11)H(6)Cl(6)或[BAr(F)(4)](Ar(F)= 3,5-(CF(3))(2) C(6)H(3))]揭示了半不稳定的DPEphos配体的作用