Sterically Directed Functionalization of Aromatic C−H Bonds: Selective Borylation Ortho to Cyano Groups in Arenes and Heterocycles
作者:Ghayoor A. Chotana、Michael A. Rak、Milton R. Smith
DOI:10.1021/ja0428309
日期:2005.8.1
Ir-catalyzed borylations of 4-substituted benzonitriles are described. In contrast to electrophilic aromatic substitutions and directed ortho metalations, C-H activation/borylation enables functionalization at the 2-position, adjacent to the cyano group, when the 4-subsitutent is larger than cyano. When an excess of borane reagent is used, diborylation can be achieved with a single regioisomer being
描述了 4-取代苄腈的 Ir 催化硼化。与亲电芳香取代和定向邻位金属化相反,当 4-取代基大于氰基时,CH 活化/硼酸化能够在与氰基相邻的 2-位进行官能化。当使用过量的硼烷试剂时,在某些情况下可以通过形成单一区域异构体来实现二硼化。还报道了空间定向硼酸化扩展到氰基取代的五元和六元环杂环。
Divergent Synthesis of 2,3,5-Substituted Thiophenes by C-H Activation/Borylation/Suzuki Coupling
作者:Robert E. Maleczka、Milton R. Smith、Venkata A. Kallepalli、Luis Sánchez、Hao Li、Nathan J. Gesmundo
DOI:10.3987/com-09-s(s)135
日期:——
C-H activation/borylation has been married with Suzuki coupling to prepare DuP 697 (1) and analogs that would be otherwise difficult to obtain via the traditional synthetic route to 1.
4-(N,N-Dimethylamine)benzonitrile (DMABN) derivatives with boronic acid and boronate groups: new fluorescent sensors for saccharides and fluoride ion
Two DMABN derivatives with boronic acid/boronate groups 1 and 2 were designed and synthesized for sensing saccharides and F−, respectively. Fluorescent spectral changes were observed for 1 after reaction with fructose, galactose, mannose and glucose, and the corresponding binding constants were estimated. The results show that compound 1 can bind fructose more strongly than other saccharides tested. Interestingly, both absorption and fluorescence spectral changes occurred for compound 2 after addition of F−, indicating that compound 2 is a potentially selective sensor for F−.