已经开发了一种用于将容易获得的外消旋、支链芳族烯丙酯转化为支链烯丙胺、醚和烷基的催化方案。钯催化的支链烯丙基酯异构化为末端烯丙基酯,然后依次进行铱催化的烯丙基取代,以良好的收率得到支链烯丙基产物,具有高区域异构和对映异构选择性。富电子和缺电子支化烯丙基酯均产生 >90% ee 的产物。对于来自乙酸2-噻吩酯和碳酸二烯酯的反应的产物,也观察到高对映体过量。
已经开发了一种用于将容易获得的外消旋、支链芳族烯丙酯转化为支链烯丙胺、醚和烷基的催化方案。钯催化的支链烯丙基酯异构化为末端烯丙基酯,然后依次进行铱催化的烯丙基取代,以良好的收率得到支链烯丙基产物,具有高区域异构和对映异构选择性。富电子和缺电子支化烯丙基酯均产生 >90% ee 的产物。对于来自乙酸2-噻吩酯和碳酸二烯酯的反应的产物,也观察到高对映体过量。
enantioselective C‐allylations of isoxazolinones. These occur with high regioselectivity in favor of the linear allylation products, although Ir phosphoramidite catalysts were used, which commonly results in branched isomers. Our studies suggest that this outcome is the result of a reaction cascade via an initial regio‐ and enantioselective N‐allylation to provide a branched allyl intermediate, followed
Asymmetric Redox Allylic Alkylation to Access 3,3′‐Disubstituted Oxindoles Enabled by Ni/NHC Cooperative Catalysis
作者:Tao Fan、Jin Song、Liu‐Zhu Gong
DOI:10.1002/anie.202201678
日期:2022.5.23
Chiral N-heterocyclic carbene and nickel cooperative catalysis enables asymmetric redox allylicalkylation to access 3,3′-disubstituted oxindoles with high enantioselectivity.
Iridium‐Catalyzed Asymmetric Allylic Substitution of Methyl Azaarenes
作者:Xi‐Jia Liu、Wen‐Yun Zhang、Chao Zheng、Shu‐Li You
DOI:10.1002/anie.202200164
日期:2022.5.9
An iridium-catalyzedasymmetricallylic substitution of a variety of methyl azaarenes, including (benzo)thiazole, oxazole, benzoimidazole, pyridine, and (iso)quinoline, is described. The corresponding chiral azaarene derivatives are afforded in good yields with high enantioselectivity (up to 96 % yield and 99 % ee).
Photochemical Allylation of Alkanes Enabled by Nickel Catalysis
作者:Youxiang Jin、Elvis Wang Hei Ng、Tao Fan、Hajime Hirao、Liu-Zhu Gong
DOI:10.1021/acscatal.2c02345
日期:2022.8.19
We have developed an allylicalkylation of alkanes by dual photo-HAT/nickel catalysis. In this reaction, radical-type hydrogen-atom-transfer of the alkanes is enabled by decatungstate as a photocatalyst, whereas nickel serves to cleave the C–O bond in the substrates under mild reaction conditions. This co-catalyzed reaction provides a method for direct functionalization of alkanes. Density functional
well-defined tridentate chiral sulfoxide-N-olefin ligand has been designed and applied in rhodium-catalyzed asymmetric allylicsubstitutions of racemic allyliccarbonates, providing the branched allylic products in good yields with good to high enantioselectivities and excellent regioselectivities. This reaction mechanism, which involves the possible hemilability of olefin coordination on sulfoxide-N-olefin