Gold(I)-Catalyzed Asymmetric Cyclopropenation of Internal Alkynes
摘要:
Highly enantioselective cyclopropenation of internal alkynes with aryldiazoacetates was achieved using the binuclear gold catalyst (S)-xylylBINAP(AuCl)(2), activated by silver hexafluoroantimonate.
在这项研究中,我们提出了一种使用简单的单锅法合成磁分离 Pd-Fe 3 O 4 @GO 催化剂的新方法。该催化剂用于Sonogashira偶联反应,显示出优异的结果。使用各种表征方法对催化剂进行了研究,包括X射线光电子能谱(XPS)、扫描电子显微镜-能量色散X射线能谱(SEM-EDS)图谱、TEM、X射线衍射(XRD)、FTIR、和电感耦合等离子体质谱(ICP-MS)。在无铜共催化和无配体条件下的苯乙炔-碘苯偶联反应中,Pd-Fe 3 O 4 @GO 表现出优于传统对应物的催化活性,周转频率(TOF)高达 118.3 h -1。优化的条件为各种底物(包括无活性的芳基氯和溴化物底物)带来了高产率,强调了其多功能性。此外,还提出了反应机理并开发了动力学模型。该催化剂的绿色化学潜力因其高效率、产品纯度、可回收性和易于制备而受到强调。此外,Pd-Fe 3 O 4 @GO 通过多次回收表现出令人印象
Silver Triflate-Catalyzed Cyclopropenation of Internal Alkynes with Donor-/Acceptor-Substituted Diazo Compounds
作者:John F. Briones、Huw M. L. Davies
DOI:10.1021/ol201503j
日期:2011.8.5
Silver triflate was found to be an efficient catalyst for the cyclopropenation of internal alkynes using donor-/acceptor-substituted diazo compounds as carbenoid precursors. Highly substituted cyclopropenes, which cannot be synthesized directly via rhodium(II)-catalyzed carbenoid chemistry, can now be readily accessed.