Palladium-catalyzed, ligand-free S N 2’ substitution reactions of organoaluminum with propargyl acetates for the synthesis of multi-substituted allenes
作者:Xuebei Shao、Chang Wen、Gang Zhang、Kangping Cao、Ling Wu、Qinghan Li
DOI:10.1016/j.jorganchem.2018.06.020
日期:2018.9
We describe a convenient method for the synthesis of multi-substituted allenes from SN2′ substitution reactions organoaluminum with propargyl acetates: The SN2′ substitution reaction of organoaluminum (0.4 mmol) with propargyl acetates (0.5 mmol) mediated by PdCl2(dppf) (1 mol%) at 60 °C in THF without ligand could produce multi-substituted allenes in moderate to good yields (up to 98%) and high selectivities
Synthesis of multi-substituted allenes from organoalane reagents and propargyl esters by using a nickel catalyst
作者:Xue Bei Shao、Zhen Zhang、Qing Han Li、Zhi Gang Zhao
DOI:10.1039/c8ob00781k
日期:——
A highly efficient and simple route for the synthesis of multi-substituted allenes has been developed by a nickel catalyzed SN2′ substitution reaction of propargyl esters with organic aluminium reagents under mild conditions, which gave the corresponding multi-substituted allenes in good to excellent yields (up to 92%) and high selectivities (up to 99%) at 60 °C for 6 h in THF. Aryls bearing electron-donating
在温和的条件下,通过炔丙基酯与有机铝试剂的镍催化的S N 2'取代反应,开发了一种高效且简单的合成多取代的烯的方法,得到了相应的优等的多取代的烯。在THF中在60°C下反应6小时可得到高产率(最高92%)和高选择性(最高99%)。炔丙基酯中带有给电子或吸电子基团的芳基收率高。另外,带有噻吩基或吡啶基的多取代的亚丙基以95-97%的选择性获得,分离产率为72-83%。此外,S N2'取代反应也与炔丙基碳酸酯化合物有效地起作用。根据实验结果,提出了可能的催化循环。