Silver-promoted cross-coupling of substituted allyl(trimethyl)silanes with aryl iodides by palladium catalysis
作者:Zhen-Lin Hou、Fan Yang、Zhibing Zhou、Yu-Fei Ao、Bo Yao
DOI:10.1016/j.tetlet.2018.11.026
日期:2018.12
A ligand-free Pd-catalyzedcross-coupling of substituted allyl(trimethyl)silanes with aryl iodides enabled by silver salts was developed. This reaction delivered allylic arenes chemoselectively and regioselectively. The study suggested that the reaction might proceed through oxidative addition of ArI to Pd(0) followed by halide abstraction to give an electrophilic complex ArPdX, which further reacted
Cobalt(II)-Catalyzed Stereoselective Olefin Isomerization: Facile Access to Acyclic Trisubstituted Alkenes
作者:Sheng Zhang、Deepika Bedi、Lu Cheng、Daniel K. Unruh、Guigen Li、Michael Findlater
DOI:10.1021/jacs.0c02101
日期:2020.5.13
Stereoselective synthesis of trisubstitutedalkenes is a long-standing challenge in organic chemistry, due to the small energy differences between E and Z isomers of trisubstitutedalkenes (compared with 1,2-disubstituted alkenes). Transition metal-catalyzed isomerization of 1,1-disubstituted alkene can serve as an alternative approach to trisubsti-tuted alkenes, but it remains underdeveloped owing
三取代烯烃的立体选择性合成是有机化学中长期存在的挑战,因为三取代烯烃的 E 和 Z 异构体之间的能量差异很小(与 1,2-二取代烯烃相比)。1,1-二取代烯烃的过渡金属催化异构化可以作为三取代烯烃的替代方法,但由于与反应效率和立体选择性有关的问题,它仍然不发达。在这里,我们展示了一种新型钴催化剂可以克服这些挑战,为获得广泛的三取代烯烃提供有效和立体选择性的途径。该协议与单烯和二烯兼容,并表现出良好的官能团耐受性和可扩展性。而且,它已被证明是构建有机发光体和氘代三取代烯烃的有用工具。对该机制的初步研究表明,该反应涉及钴氢化物途径。该反应的高立体选择性归因于 π-π 堆积效应和底物和催化剂之间的空间位阻。
Pd-catalyzed ligand-free Suzuki reaction of β-substituted allylic halides with arylboronic acids in water
The combination of Pd(TFA)2 and KOH could efficiently catalyze the reaction of β-substituted allylic halides with arylboronic acids in water.
Pd(TFA)2和KOH的组合可以有效地催化β-取代烯丙基卤化物与芳基硼酸的反应在水中进行。
Dual nickel and Lewis acid catalysis for cross-electrophile coupling: the allylation of aryl halides with allylic alcohols
作者:Xue-Gong Jia、Peng Guo、Jicheng Duan、Xing-Zhong Shu
DOI:10.1039/c7sc03140h
日期:——
selectively. The reaction tolerates a wide range of functional groups (e.g. silanes, boronates, anilines, esters, alcohols, and various heterocycles) and works with various allylicalcohols. Complementary to most current routes for the C3 allylation of an unprotected indole, this method provides access to C2 and C4–C7 allylated indoles. Preliminary mechanistic experiments reveal that the reaction might start
Oxidative cross-coupling of allyl(trimethyl)silanes with aryl boronic acids by palladium catalysis
作者:Zhibing Zhou、Zhen-Lin Hou、Fan Yang、Bo Yao
DOI:10.1016/j.tet.2018.10.055
日期:2018.12
allylsilanes with aryl boronic acids has been developed by palladium catalysis. The reaction between β-substituted allyl(trimethyl)silanes and a wide range of aryl boronic acids afforded allylarenes in moderate to good yields and excellent selectivity. On the basis of experimental results and literature reports, it was suggested that the reaction might start from transmetalation of aryl boronic acid with AgOAc