Synergetic Catalysis for One‐pot Bis‐alkoxycarbonylation of Terminal Alkynes over Pd/Xantphos−Al(OTf)
<sub>3</sub>
Bi‐functional Catalytic System
作者:Wen‐Di Guo、Lei Liu、Shu‐Qing Yang、Xiao‐Chao Chen、Yong Lu、Giang VO‐Thanh、Ye Liu
DOI:10.1002/cctc.201901988
日期:2020.3.6
bi‐functional catalytic system containing Xantphos‐modified Pd‐complex and Lewis super‐acid of Al(OTf)3. It was found that, via the synergetic catalysis, the involved Xantphos‐modified Pd‐complex was responsible for the activation of CO and the alkynes through coordination to Pd‐center while Al(OTf)3 was in charge of the activation of the alcohol to facilitate the formation of [Pd−H]+ active species. The
炔烃的串联双烷氧基羰基化可通过两次连续的烷氧基羰基化,从炔烃和亲核醇制备2-取代的琥珀酸酯,具有100%原子经济性和简化的一锅操作的优点。本文中,炔烃的一锅串联双烷氧基羰基化反应是在含有Xantphos修饰的Pd络合物和Al(OTf)3的Lewis超强酸的双功能催化体系上完成的。结果发现,通过协同催化作用,参与的Xantphos修饰的Pd-络合物通过与Pd中心的配位而负责CO和炔烃的活化,而Al(OTf)3负责将酒精活化为Pd-络合物。促进[Pd-H] +活性物质的形成。在原位高压FT-IR分析,结合1 H / 13 C NMR光谱表征,证实引入的具有强亲氧性(通过酸碱对相互作用)的Al(OTf)3能够活化亲核MeOH成为可靠的质子-供体(即氢化物源)以保证在P + 0被H +(Pd 0 + H + →[Pd II -H] +)氧化后[Pd-H] +物种的形成和稳定性。在已开发的双功能催化