Ligand‐Controlled Palladium‐Catalyzed Carbonylation of Alkynols: Highly Selective Synthesis of α‐Methylene‐β‐Lactones
作者:Yao Ge、Fei Ye、Jiawang Liu、Ji Yang、Anke Spannenberg、Haijun Jiao、Ralf Jackstell、Matthias Beller
DOI:10.1002/anie.202006550
日期:2020.11.23
The first general and regioselective Pd‐catalyzed cyclocarbonylation to give α‐methylene‐β‐lactones is reported. Key to the success for this process is the use of a specific sterically demanding phosphine ligand based on N‐arylated imidazole (L11) in the presence of Pd(MeCN)2Cl2 as pre‐catalyst. A variety of easily available alkynols provide under additive‐free conditions the corresponding α‐methylene‐β‐lactones
报道了第一个普通的和区域选择性的Pd催化的环羰基化反应,生成α-亚甲基-β-内酯。该工艺成功的关键是在Pd(MeCN)2 Cl 2作为预催化剂的情况下,使用基于N-芳基化咪唑(L11)的特定空间要求的膦配体。在无添加剂条件下,各种容易获得的炔醇以中等至良好的产率提供相应的α-亚甲基-β-内酯,具有出色的区域选择性和非对映选择性。这种新方法的适用性通过包括天然产物在内的生物活性分子的直接羰基化得以展示。