末端炔烃的Z选择性官能化是有机化学中的有用转变,主要由贵金属催化。在这里,我们介绍了由稳定的反式-二酐铁络合物[(PC NHC P)Fe(H)2 N 2)](2)催化的末端炔烃的Z选择性氢硼化。总的来说,该反应在室温下发生,并提供接近定量的Z-乙烯基硼酸酯。有趣的是,相同的催化剂也可以提供E-在稍微升高的温度(50°C)下加热反应混合物,生成-乙烯基硼酸酯。但是,如果该反应是在不存在HBpin的情况下进行的,则会观察到快速的Z选择性炔烃二聚化,这将在本报告中进一步讨论。
An efficient Cu-catalyzed C–H alkenylation with acyclic and cyclic vinyl boronates was realized for the first time under mild conditions. The scope of the vinyl borons and the compatibility with functional groups including heterocycles are superior than Pd-catalyzed C–H coupling with vinyl borons, providing a reliable access to multisubstituted alkenes and dienes. Subsequent hydrogenation of the product
Vinylation of Benzylic Amines via C–N Bond Functionalization of Benzylic Pyridinium Salts
作者:Mary Watson、Weiye Guan、Jennie Liao
DOI:10.1055/s-0037-1610084
日期:2018.8
Published as part of the Special Topic Modern Coupling Approaches and their Strategic Applications in Synthesis Abstract Cross-couplings of benzylic pyridinium salts and vinylboronic acids or esters have been developed. Via benzylic pyridinium intermediates, benzylic amines can be engaged in these cross-couplingsthrough C–N bond functionalization. This method boasts mild reaction conditions and excellent
Practical Solvent-Free Microwave-Assisted Hydroboration of Alkynes
作者:Julia Altarejos、David Sucunza、Juan J. Vaquero、Javier Carreras
DOI:10.1002/ejoc.202000110
日期:2020.5.29
A general method for solvent‐free hydroboration of alkynes has been developed by microwave irradiation, to get (E )‐alkenyl boronates. Several functionalizations in the C–B bond can be performed sequentially without the purification of the intermediates.
Lithium compounds as single site catalysts for hydroboration of alkenes and alkynes
作者:Milan Kumar Bisai、Sandeep Yadav、Tamal Das、Kumar Vanka、Sakya S. Sen
DOI:10.1039/c9cc05783h
日期:——
The hydroboration of alkenes and alkynes using easily accessible lithium compounds [2,6-di-tert-butyl phenolatelithium (1a) and 1,1′ dilithioferrocene (1b)] has been achieved with good yields, high functional group tolerance and excellent chemoselectivity. Deuterium-labeling experiments confirm the cis-addition of pinacolborane. The methodology has been further extended to myrcene, which undergoes