Catalytic Electrophilic C-H Silylation of Pyridines Enabled by Temporary Dearomatization.
Catalytic Electrophilic C-H Silylation of Pyridines Enabled by Temporary Dearomatization.
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DOI：
10.1002/anie.201508181
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发表时间：
2015-12
影响因子：
--
通讯作者：
Simon Wübbolt;M. Oestreich
中科院分区：
文献类型：
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作者：
Simon Wübbolt;M. Oestreich
本文报道了吡啶类化合物的C-OH硅烷化反应，该反应似乎是通过亲电芳香取代（SE-Ar）进行的。2-和3-取代的吡啶与氢硅烷在催化剂存在下的反应，该催化剂将Si = H键分裂成氢化物和硅亲电体，产生相应的5-甲硅烷基化吡啶。芳族C13 H键的这种形式甲硅烷基化是三步序列的结果，包括吡啶氢化硅烷化、中间体烯胺的分解C13 H甲硅烷基化和1，4-二氢吡啶逆氢化硅烷化。通过（1）H NMR光谱检测关键中间体并通过各个步骤制备。亲电硅烷化、氢化物转移和质子提取的复杂相互作用由单一催化剂促进。
A CH silylation of pyridines that seemingly proceeds through electrophilic aromatic substitution (SE Ar) is reported. Reactions of 2- and 3-substituted pyridines with hydrosilanes in the presence of a catalyst that splits the SiH bond into a hydride and a silicon electrophile yield the corresponding 5-silylated pyridines. This formal silylation of an aromatic CH bond is the result of a three-step sequence, consisting of a pyridine hydrosilylation, a dehydrogenative CH silylation of the intermediate enamine, and a 1,4-dihydropyridine retro-hydrosilylation. The key intermediates were detected by (1) H NMR spectroscopy and prepared through the individual steps. This complex interplay of electrophilic silylation, hydride transfer, and proton abstraction is promoted by a single catalyst.