Iron-Catalyzed Highly Enantioselective Hydrogenation of Alkenes
作者:Peng Lu、Xiang Ren、Haofeng Xu、Dongpo Lu、Yufeng Sun、Zhan Lu
DOI:10.1021/jacs.1c04773
日期:2021.8.18
for the first time an iron-catalyzed highlyenantioselectivehydrogenation of minimally functionalized 1,1-disubstituted alkenes to accesschiral alkanes with full conversion and excellent ee. A novel chiral 8-oxazoline iminoquinoline ligand and its iron complex have been designed and synthesized. This protocol is operationally simple by using 1 atm of hydrogen gas and shows good functional group tolerance
Olefins are prevalent substrates and functionalities. The synthesis of olefins from readily available starting materials such as alcohols, amines and carboxylic acids is of great significance to address the sustainability concerns in organic synthesis. Metallaphotoredox-catalyzed defunctionalizations were reported to achieve such transformations under mild conditions. However, all these valuable strategies
Copper‐Catalyzed Formal [2+2+1] Heteroannulation of Alkenes, Alkylnitriles, and Water: Method Development and Application to a Total Synthesis of (±)‐Sacidumlignan D
作者:Tu M. Ha、Claire Chatalova‐Sazepin、Qian Wang、Jieping Zhu
DOI:10.1002/anie.201604528
日期:2016.8
A copper‐catalyzed three‐component reaction of alkenes, alkylnitriles, and water affords γ‐butyrolactones in good yields. The domino process involves an unprecedented hydroxy‐cyanoalkylation of alkenes and subsequent lactonization with the creation of three chemical bonds and a quaternary carbon center. The synthetic potential of this novel [2+2+1] heteroannulation reaction was illustrated by a concise
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。
Copper-Catalyzed Oxidative Heck Reactions between Alkyltrifluoroborates and Vinyl Arenes
作者:Timothy W. Liwosz、Sherry R. Chemler
DOI:10.1021/ol401220b
日期:2013.6.21
potassium alkyltrifluoroborates can be utilized in oxidative Heck-type reactions with vinyl arenes. The reaction is catalyzed by a Cu(OTf)2/1,10-phenanthroline with MnO2 as the stoichiometric oxidant. In addition to the alkyl Heck, amination, esterification, and dimerization reactions of alkyltrifluoroborates are demonstrated under analogous reaction conditions. Evidence for an alkyl radical intermediate