Practical and Scalable Synthesis of Borylated Heterocycles Using Bench-Stable Precursors of Metal-Free Lewis Pair Catalysts
作者:Arumugam Jayaraman、Luis C. Misal Castro、Frédéric-Georges Fontaine
DOI:10.1021/acs.oprd.8b00248
日期:2018.11.16
A practical and scalable metal-free catalytic method for the borylation and borylative dearomatization of heteroarenes has been developed. This synthetic method uses inexpensive and conveniently synthesizable bench-stable precatalysts of the form 1-NHR2-2-BF3-C6H4, commercially and synthetically accessible heteroarenes as substrates, and pinacolborane as the borylation reagent. The preparation of several
已开发出一种实用且可扩展的无杂芳烃的硼化和硼基脱芳香化的无金属催化方法。这种合成方法使用廉价且可方便合成的1-NHR 2 -2-BF 3 -C 6 H 4形式的台式稳定型预催化剂。,市售和合成途径可得到的杂芳烃作为底物,频哪醇硼烷作为硼化试剂。在无溶剂条件下,无需使用Schlenk技术或手套箱即可制备2和50 g规模的数个硼化杂环。使用这种经济高效的绿色方法还可以实现其中一种杂芳烃底物的公斤级硼化,这证明了我们的方法可以在精细化工行业中方便地实施的事实。
Organophosphorus-catalyzed relay oxidation of H-Bpin: electrophilic C–H borylation of heteroarenes
作者:Jeffrey M. Lipshultz、Yue Fu、Peng Liu、Alexander T. Radosevich
DOI:10.1039/d0sc05620k
日期:——
phosphorus triamide (1, PN[o-NMe-C6H4]2}) is shown to catalyze C–H borylation of electron-rich heteroarenes with pinacolborane (HBpin) in the presence of a mild chloroalkane reagent. C–H borylation proceeds for a range of electron-rich heterocycles including pyrroles, indoles, and thiophenes of varied substitution. Mechanistic studies implicate an initial P–N cooperative activation of HBpin by 1 to give
Zinc catalysed C3–H borylation of indoles and 1,1-diboration of terminal alkynes
作者:Binfeng Zhang、Youliang Zou、Li Wang、Hua Zhang
DOI:10.1039/d1cc04497d
日期:——
transformation represents the use of an abundant, cheap and environmentally benign zinc catalyst in catalytic direct aromatic C–H borylation and offers a simple and prompt route towards the synthesis of C3-borylated indoles. The 1,1-diboration of terminal alkynes was also achieved using the same catalytic system to produce 1,1-diborylated alkenes.
Metal-Free Arene and Heteroarene Borylation Catalyzed by Strongly Electrophilic Bis-boranes
作者:Yun-Lin Liu、Gerald Kehr、Constantin G. Daniliuc、Gerhard Erker
DOI:10.1002/chem.201701771
日期:2017.9.7
The geminal chelate bis‐borylalkanes 4 and 5 featuring strongly electrophilic B(C6F5)2 and B(C6F5) groups, respectively, serve as efficient catalysts for the borylation of arenes and heteroarenes. The borylation reactions proceed under mild conditions with liberation of dihydrogen.
具有强亲电性B(C 6 F 5)2和B(C 6 F 5)基团的双螯合双硼烷基烷 4和5可作为芳烃和杂芳烃硼化的有效催化剂。硼酸酯化反应在温和条件下进行,释放出二氢。
Cobalt-Catalyzed C–H Borylation of Alkyl Arenes and Heteroarenes Including the First Selective Borylations of Secondary Benzylic C–H Bonds
作者:Chathurika R. K. Jayasundara、Dmitrijs Sabasovs、Richard J. Staples、Jossian Oppenheimer、Milton R. Smith、Robert E. Maleczka
DOI:10.1021/acs.organomet.8b00144
日期:2018.5.29
A cobalt di-tert-butoxide complex bearing N-heterocyclic carbene (NHC) ligands has been synthesized and characterized. This complex is effective at catalyzing the selective monoborylation of the benzylic position of alkyl arenes using pinacolborane (HBpin) as the boron source. This same cobalt complex enables selective monoborylation of N-methylpyrrole, N-methylpyrazole, and N-methylindole. Catalysis