Alkaline-Earth Metal Mediated Benzene-to-Biphenyl Coupling

Mai J, Morasch M, Jedrzkiewicz D, Langer J, Rösch B, Harder S (2022)

Publication Type: Journal article

Publication year: 2022

Journal

DOI: 10.1002/anie.202212463

Abstract

Complex [(^DIPePBDI)Ca]2(C6H6), with a C6H6²⁻ dianion bridging two Ca²⁺ ions, reacts with benzene to yield [(^DIPePBDI)Ca]2(biphenyl) with a bridging biphenyl²⁻ dianion (^DIPePBDI=HC[C(Me)N-DIPeP]2; DIPeP=2,6-CH(Et)2-phenyl). The biphenyl complex was also prepared by reacting [(^DIPePBDI)Ca]2(C6H6) with biphenyl or by reduction of [(^DIPePBDI)CaI]2 with KC8 in presence of biphenyl. Benzene-benzene coupling was also observed when the deep purple product of ball-milling [(^DIPPBDI)CaI(THF)]2 with K/KI was extracted with benzene (DIPP=2,6-CH(Me)2-phenyl) giving crystalline [(^DIPPBDI)Ca(THF)]2(biphenyl) (52 % yield). Reduction of [(^DIPePBDI)SrI]2 with KC8 gave highly labile [(^DIPePBDI)Sr]2(C6H6) as a black powder (61 % yield) which reacts rapidly and selectively with benzene to [(^DIPePBDI)Sr]2(biphenyl). DFT calculations show that the most likely route for biphenyl formation is a pathway in which the C6H6²⁻ dianion attacks neutral benzene. This is facilitated by metal-benzene coordination.

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How to cite

APA:

Mai, J., Morasch, M., Jedrzkiewicz, D., Langer, J., Rösch, B., & Harder, S. (2022). Alkaline-Earth Metal Mediated Benzene-to-Biphenyl Coupling. Angewandte Chemie International Edition. https://doi.org/10.1002/anie.202212463

MLA:

Mai, Jonathan, et al. "Alkaline-Earth Metal Mediated Benzene-to-Biphenyl Coupling." Angewandte Chemie International Edition (2022).

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