Enantioselective cyanation of benzylic C–H bonds via copper-catalyzed radical relay
作者:Wen Zhang、Fei Wang、Scott D. McCann、Dinghai Wang、Pinhong Chen、Shannon S. Stahl、Guosheng Liu
DOI:10.1126/science.aaf7783
日期:2016.9.2
sp3-hybridized carbon–hydrogen [C(sp3)–H] bonds in complex organic molecules could facilitate much more efficient preparation of therapeutics and agrochemicals. Here, we report a copper-catalyzed radical relay pathway for enantioselective conversion of benzylic C–H bonds into benzylic nitriles. Hydrogen-atom abstraction affords an achiral benzylic radical that undergoes asymmetric C(sp3)–CN bond formation upon
isoindoloisoquinolinones, pyrroloisoquinolinones, and benzo[a]quinolizinones were successfully assembled from the corresponding imides by using a TfOH-mediated (TfOH = trifluoromethanesulfonic acid) imidecarbonylactivation and cyclization strategy. By employing this simple method, the isoquinoline alkaloids crispine A, trolline/oleracein E, and erythrinarbine were successfully synthesized in racemic form. The reaction
Copper-Catalyzed Alkynylation of Benzylic C–H Bonds with Alkynylboronic Esters
作者:Søren Kramer、Mikkel B. Buendia、Jan-Georges J. Balin、Mette E. Andersen、Zhong Lian
DOI:10.1055/s-0040-1720474
日期:2022.1
method for copper-catalyzed benzylic C–Halkynylation that uses alkynylboronic esters as nucleophilic coupling partners. The catalytic system is readily available and the reaction takes place under mild conditions. Different substrates for the C–H functionalization, as well as various alkynylboronic ester nucleophiles, were evaluated. Finally, three examples of enantioselective C–Halkynylations are presented
Copper-Catalyzed Arylation of Benzylic C–H bonds with Alkylarenes as the Limiting Reagents
作者:Wen Zhang、Pinhong Chen、Guosheng Liu
DOI:10.1021/jacs.7b03781
日期:2017.6.14
A novel copper-catalyzedarylation of benzylic C-H bonds with nucleophilic arylboronic acids has been developed that provides an efficient way to synthesize various 1,1-diarylalkanes with a broad substrate scope and excellent functional group compatibility. The reactions occur at room temperature using alkylarenes as the limiting reagents, which allows access to the arylation of the more valuable and
Enantioselective Arylation of Benzylic C−H Bonds by Copper‐Catalyzed Radical Relay
作者:Wen Zhang、Lianqian Wu、Pinhong Chen、Guosheng Liu
DOI:10.1002/anie.201902191
日期:2019.5.6
A novel enantioselective copper‐catalyzed arylation of benzylic C−H bonds, using alkylarenes as a limiting reagent, has been developed. A chiral bisoxazoline ligand bearing an acetate ester moiety plays a key role in both the reactivity and enantioselectivity of the reaction. The reaction provides efficient access to various chiral 1,1‐diarylalkanes in good yields with good to excellent enantioselectivities