Cyclopalladated Compounds with Polyhalogenated Benzylphosphanes for the Mizoroki‐Heck Reaction
作者:Cristina López‐Mosquera、Arnald Grabulosa、Mercè Rocamora、Mercè Font‐Bardia、Guillermo Muller
DOI:10.1002/ejic.202000288
日期:2020.7.7
been prepared. Treatment with norbornadiene in the presence of silver tetrafluoroborate has furnished the cationic mononuclear complexes [Pd(κ2‐C,P ‐ArXCH2PR2)(nbd)]BF4 as stable solids. These complexes and some of the bromide dimers have been used as catalytic precursors in the Mizoroki‐Heck reaction between bromobenzene and butyl acrylate. The complexes efficiently catalyse this transformation and important
制备了九个部分卤代的苄基膦Ar X CH 2 PR 2(Ar X = 3,6-二氯苯基,3,6-二氟苯基和3,4,5-三氟苯基; R = Ph,Cy,i Pr)并与钯反应乙酸,得到环金属化的二聚体[加入Pd(μ -OAc)(κ 2 - C,P -Ar X CH 2 PR 2)] 2。已使用溴化锂通过溴化物交换了乙酸酯桥,并且已对得到的二聚体进行了全面表征。非卤代膦PhCH 2 PR 2(R = Ph,iPr)也已经准备好了。处理中的四氟硼酸银的存在降冰片二烯提供装饰的阳离子单核配合物[钯(κ 2 - C,P -Ar X CH 2 PR 2)(NBD)] BF 4为稳定的固体。这些络合物和一些溴化物二聚体已被用作溴苯和丙烯酸丁酯之间的Mizoroki-Heck反应的催化前体。配合物有效地催化这种转化,并且根据配体发现活性的重要差异。通常,氟化膦比氯化类似物具有更多的活性体系。