Bis(imidazolin-2-ylidene-1-yl)borate Complexes of the Heavier Alkaline Earths: Synthesis and Studies of Catalytic Hydroamination
作者:Merle Arrowsmith、Michael S. Hill、Gabriele Kociok-Köhn
DOI:10.1021/om8010933
日期:2009.3.23
sufficient to maintain the metal−ligand binding in the presence of amine donors and has allowed the evaluation of the Ca and Sr complexes [H2B(ImtBu)2}MN(SiMe3)2}(THF)n] as precatalysts for the intramolecularhydroamination of aminoalkenes. While the calcium catalyst provides activities commensurate with our previously reported β-diketiminato complex, [CHC(Me)N(2,6-iPr2C6H3)}CaN(SiMe3)2}(THF)], the strontium
可以通过在[KN(SiMe 3)2 ]的存在下将硼盐配体前体进行去质子化反应,合成重金属碱土元素钙和锶的杂配物,其中双(咪唑啉-2-亚甲基-1-基)硼酸酯配体蔡2或SRI 2。甲硅烷基酰胺配合物[H 2 B(Im t Bu)2 } M N(SiMe 3)2 }(THF)n ](M = Ca,n = 1; M = Sr,n = 2),含有N-叔丁基取代的咪唑啉-2-亚烷基片段对分子间溶液重新分布稳定,尽管在M = Ca的情况下有溶液流动性的证据。尝试合成含碘化氢的杂合物种导致分离出均化化合物[H 2 B(Im t Bu)2 } 2 MTHF)n ](M = Ca,n = 1; M = Sr,n = 2)最有可能是因为卤化物大肠菌素的空间需求减少了。尽管将“一锅法”合成方法扩展到含有N-间苯二甲酰基取代的咪唑的前体会导致配体大量降解,但仍使用[Ca N(SiMe 3)2 } 2(THF)2