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The Synthesis of [Sn10SiSiMe334]2- Using a Metastable SnI Halide Solution Synthesized via a Co-condensation Technique
Published on: November 28, 2016
Modulating halide leaving-group trends through recognition by bisboranes
Tong-Tong Liu1, Xiao-Wen Li1, Yun-Shu Cui1
1Department of Chemistry, Fudan University Shanghai 200438 P. R. China zjshi@fudan.edu.cn zhaidandan@fudan.edu.cn liufeng@fudan.edu.cn.
None:
Modulating the intrinsic leaving-group tendency of halides remains a long-standing challenge in synthetic chemistry. Herein, we reported dynamic anion recognition and demonstrated its application in nucleophilic substitution reactions, enabling an apparent reversal of the halide leaving-group tendency sequence. A bidentate Lewis acid-based platform was developed to selectively bind halide ions, forming host-guest complexes that were characterized by NMR spectroscopy and X-ray crystallography. Competitive experiments with the host molecule have revealed tunable binding affinities for the halides based on the cavity size of the bisboron center. Moreover, anion exchange experiments have demonstrated that the dynamic binding of halides is primarily influenced by their nucleophilicity and ion radius. The recognition of organohalides by diborane hosts induced a reversal of the leaving ability of Br- and Cl- in diborane-catalyzed transformations, which deviated from the conventional sequence.
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