A site-selective amination catalyst discriminates between nearly identical C-H bonds of unsymmetrical disubstituted alkenes
A site-selective amination catalyst discriminates between nearly identical C-H bonds of unsymmetrical disubstituted alkenes
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DOI：
10.1038/s41557-020-0470-z
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发表时间：
2020-06-15
期刊：
影响因子：
21.8
通讯作者：
Rovis, Tomislav
中科院分区：
文献类型：
--
作者：
Lei, Honghui;Rovis, Tomislav
C-H活化反应使化学家能够揭示新的逆合成断开和简化传统的合成方法。C-H活化的一个长期挑战是无法区分电子和空间相似的C-H键。尽管过渡金属络合物和螯合导向基团的许多协同组合已被用于区分C-H键，但无方向的区域选择性C-H官能化策略仍然难以捉摸。本文报道了一种不对称二烷基取代烯烃的区域选择性C-H活化/胺化反应。C-H活化的区域选择性与烯丙基C-H键的电子性质相关，由相应的（1）J（CH）耦合常数表示。还确定了两个竞争烯丙基C-H键的（1）J（CH）偶合常数之差（Δ（1）J（CH））与C-H活化能垒（Δ Δ G双刃）之间的线性关系。
C-H activation reactions enable chemists to unveil new retrosynthetic disconnections and streamline conventional synthetic approaches. A long-standing challenge in C-H activation is the inability to distinguish electronically and sterically similar C-H bonds. Although numerous synergistic combinations of transition-metal complexes and chelating directing groups have been utilized to distinguish C-H bonds, undirected regioselective C-H functionalization strategies remain elusive. Here we report a regioselective C-H activation/amination reaction of various unsymmetrical dialkyl-substituted alkenes. The regioselectivity of C-H activation is correlated to the electronic properties of allylic C-H bonds indicated by the corresponding(1)J(CH)coupling constants. A linear relationship between the difference in the (1)J(CH) coupling constants of the two competing allylic C-H bonds (Delta(1)J(CH)) and the C-H activation barriers (Delta Delta G double dagger) has also been determined.