Evidence for the Existence of Group 3 Terminal Methylidene Complexes
Evidence for the Existence of Group 3 Terminal Methylidene Complexes
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DOI：
10.1021/acs.organomet.6b00394
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发表时间：
2017-01-09
期刊：
影响因子：
2.8
通讯作者：
Andersen, Richard A.
中科院分区：
文献类型：
--
作者：
Levine, Daniel S.;Tilley, T. Don;Andersen, Richard A.
端基3亚甲基配合物是由单阴离子PNP负载的钪和钇的二烷基配合物的热分解产生的。氘标记实验和密度泛函理论计算探讨了反应机理。通过另一个从一个烷基中提取γ-氢得到金属-杂环丁烷，其经历[2 + 2]环逆转，类似于烯烃复分解反应中的关键步骤，以产生亚甲基络合物和异丁烯。在钪的情况下，所得到的亚甲基络合物二聚化，在钇的情况下分解成产物的混合物。
Terminal group 3 methylidene complexes are generated by thermolysis of monoanionic PNP-supported scandium and yttrium dialkyl complexes. The reaction mechanism has been probed by deuterium-labeling experiments and DFT calculations. Abstraction of a y-hydrogen from one alkyl group by the other affords a metal-lacyclobutane that undergoes [2 + 2] cycloreversion, analogous to a key step in the olefin metathesis reaction, to generate a methylidene complex and isobutene. The resulting methylidene complex dimerizes in the case of scandium and decomposes to a mixture of products in the case of yttrium.