1433269-77-2Relevant academic research and scientific papers
Cobalt(II)-Catalyzed Stereoselective Olefin Isomerization: Facile Access to Acyclic Trisubstituted Alkenes
Zhang, Sheng,Bedi, Deepika,Cheng, Lu,Unruh, Daniel K.,Li, Guigen,Findlater, Michael
supporting information, p. 8910 - 8917 (2020/12/23)
Stereoselective synthesis of trisubstituted alkenes is a long-standing challenge in organic chemistry, due to the small energy differences between E and Z isomers of trisubstituted alkenes (compared with 1,2-disubstituted alkenes). Transition metal-catalyzed isomerization of 1,1-disubstituted alkenes can serve as an alternative approach to trisubstituted alkenes, but it remains underdeveloped owing to issues relating to reaction efficiency and stereoselectivity. Here we show that a novel cobalt catalyst can overcome these challenges to provide an efficient and stereoselective access to a broad range of trisubstituted alkenes. This protocol is compatible with both mono- and dienes and exhibits a good functional group tolerance and scalability. Moreover, it has proven to be a useful tool to construct organic luminophores and a deuterated trisubstituted alkene. A preliminary study of the mechanism suggests that a cobalt-hydride pathway is involved in the reaction. The high stereoselectivity of the reaction is attributed to both a π-πstacking effect and the steric hindrance between substrate and catalyst.
Boronic acid-mediated ring-opening and Ni-catalyzed arylation of 1-arylcyclopropyl tosylates
Mills, L. Reginald,Monteith, John J.,Rousseaux, Sophie A. L.
, p. 12538 - 12541 (2020/11/02)
Herein, we describe a protocol for the ring-opening arylation of 1-arylcyclopropyl tosylates, in which boronic acids promote ring-opening and a Ni catalyst facilitates arylation in high regioselectivity. A number of 2-arylated allyl derivatives are synthesized, which are relevant motifs found in biologically active molecules.
Silver-promoted cross-coupling of substituted allyl(trimethyl)silanes with aryl iodides by palladium catalysis
Hou, Zhen-Lin,Yang, Fan,Zhou, Zhibing,Ao, Yu-Fei,Yao, Bo
supporting information, p. 4557 - 4561 (2018/11/27)
A ligand-free Pd-catalyzed cross-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 with allyl(trimethyl)silanes via electrophilic addition/desilylation/reductive elimination to afford the allyl-aryl coupling products.
Oxidative cross-coupling of allyl(trimethyl)silanes with aryl boronic acids by palladium catalysis
Zhou, Zhibing,Hou, Zhen-Lin,Yang, Fan,Yao, Bo
, p. 7228 - 7236 (2018/11/03)
The first oxidative cross-coupling of 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 followed by transmetalation with Pd(II) to give an arylpalladium acetate complex as a key intermediate. This intermediate underwent either electrophilic addition/desilylation or transmetalation with allylsilane and subsequent reductive elimination to give the final product.
Dual nickel and Lewis acid catalysis for cross-electrophile coupling: The allylation of aryl halides with allylic alcohols
Jia, Xue-Gong,Guo, Peng,Duan, Jicheng,Shu, Xing-Zhong
, p. 640 - 645 (2018/01/28)
Controlling the selectivity in cross-electrophile coupling reactions is a significant challenge, particularly when one electrophile is much more reactive. We report a general and practical strategy to address this problem in the reaction between reactive and unreactive electrophiles by a combination of nickel and Lewis acid catalysis. This strategy is used for the coupling of aryl halides with allylic alcohols to form linear allylarenes selectively. The reaction tolerates a wide range of functional groups (e.g. silanes, boronates, anilines, esters, alcohols, and various heterocycles) and works with various allylic alcohols. 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 with an aryl nickel intermediate, which then reacts with Lewis acid activated allylic alcohols in the presence of Mn.
Pd-catalyzed ligand-free Suzuki reaction of β-substituted allylic halides with arylboronic acids in water
Dong, Chaonan,Zhang, Lingjuan,Xue, Xiao,Li, Huanrong,Yu, Zhiyong,Tang, Weijun,Xu, Lijin
, p. 11152 - 11158 (2014/03/21)
The catalyst system consisting of Pd(TFA)2 and KOH allows for a wide range of β-substituted allylic halides to react efficiently with various arylboronic acids in neat water under ligand-free conditions, affording the allylated arenes in high yields with broad functional group tolerance and up to 7.4 × 105 TON and 15416 h-1 TOF.
Nickel-catalyzed reductive allylation of aryl bromides with allylic acetates
Cui, Xiaozhan,Wang, Shulin,Zhang, Yuwei,Deng, Wei,Qian, Qun,Gong, Hegui
supporting information, p. 3094 - 3097 (2013/05/23)
This paper highlights Ni-catalyzed allylation of electron-rich aryl bromides with a variety of substituted allylic carbonates using zinc as the terminal reductant, affording E-alkenes regioselectively in good to excellent yields by the addition of aryl to the less hindered allylic carbon. The electron-deficient aryl bromides and chlorides are also highly efficient coupling partners. The Royal Society of Chemistry 2013.
