step of these reactions. Electron-withdrawing as well as -donating substituents at the phenyl group increase the reaction rate. Quantum chemical computations did not reveal any correlation between either the enthalpy or Gibbs free energy of the N–C bond cleavage step and the experimentally determined first-order rate constants. Instead, the structural difference between the excitedstate generated by
A highly selective hydrogenation of alkynesusing an air-stable and readily available manganese catalyst has been achieved. The reaction proceeds under mild reaction conditions and tolerates various functional groups, resulting in (Z)-alkenes and allylic alcohols in high yields. Mechanistic experiments suggest that the reaction proceeds via a bifunctional activation involving metal–ligand cooperativity
Nickel-Mediated Inter- and Intramolecular Reductive Cross-Coupling of Unactivated Alkyl Bromides and Aryl Iodides at Room Temperature
作者:Chang-Song Yan、Yu Peng、Xiao-Bo Xu、Ya-Wen Wang
DOI:10.1002/chem.201200190
日期:2012.5.7
A nickel‐mediated intermolecular reductivecross‐coupling reaction of unactivated alkyl bromides and aryl iodides at room temperature has been developed and successfully extended to less explored intramolecular versions and tandem cyclization‐intermolecular cross‐coupling. Highly stereoselective (or stereospecific) synthesis of linear‐fused perhydrofuro[2,3‐b]furan (pyran) and spiroketal skeletons
已开发出室温下未活化的烷基溴和芳基碘的镍介导的分子间还原性交叉偶联反应,并成功地扩展到较少探索的分子内版本和串联环化-分子间交叉偶联。线性稠合的全氢呋喃[2,3- b ]呋喃(吡喃)和螺环骨架的高度立体选择性(或立体定向)合成可以快速获得这些有用的结构单元,这在相关天然产物的合成中可能具有潜在的价值。给出了形成连续立体中心的合理解释。
Nickel‐Catalysed Cross‐Electrophile Coupling of Benzyl Bromides and Sulfonium Salts towards the Synthesis of Dihydrostilbenes
作者:Roberto del Río‐Rodríguez、Laura Blanco、Alba Collado、Jose A. Fernández‐Salas、José Alemán
DOI:10.1002/chem.202201644
日期:2022.9.27
nickel-catalysed reductive cross-coupling reaction between benzyl sulfoniumsalts and benzyl bromides is reported. Simple, stable and readily available sulfoniumsalts have shown their ability as leaving groups in cross-electrophile coupling, allowing the construction of challenging sp3–sp3 carbon-carbon bonds, towards the synthesis of interesting dihydrostilbene derivatives.