%0 Journal Article
%A Ranjit, Sadananda
%A Lee, Richmond
%A Heryadi, Dodi
%A Shen, Chao
%A Wu, Ji’En
%A Zhang, Pengfei
%A Huang, Kuo-Wei
%A Liu, Xiaogang
%D 2016
%T Copper-Mediated C–H
Activation/C–S Cross-Coupling
of Heterocycles with Thiols
%U https://acs.figshare.com/articles/journal_contribution/Copper_Mediated_C_H_Activation_C_S_Cross_Coupling_of_Heterocycles_with_Thiols/2589676
%R 10.1021/jo2017444.s001
%2 https://acs.figshare.com/ndownloader/files/4236469
%K alkyl thiols
%K aryl
%K thiolation reactions
%K bond
%K hydrogen atom abstraction pathway
%K indole substrates
%K electron transfer
%K reaction mechanism
%K bipyridine
%K stoichiometric CuI
%K ThiolsWe report
%K elimination
%K Na 2CO
%K bidentate ligand
%K alkyl group
%K hydrogen atom transfer
%X We report the synthesis of a series of aryl- or alkyl-substituted
2-mercaptobenzothiazoles by direct thiolation of benzothiazoles with
aryl or alkyl thiols via copper-mediated aerobic C–H bond activation
in the presence of stoichiometric CuI, 2,2′-bipyridine and
Na2CO3. We also show that the approach can be
extended to thiazole, benzimidazole, and indole substrates. In addition,
we present detailed mechanistic investigations on the Cu(I)-mediated
direct thiolation reactions. Both computational studies and experimental
results reveal that the copper–thiolate complex [(L)Cu(SR)]
(L: nitrogen-based bidentate ligand such as 2,2′-bipyridine;
R: aryl or alkyl group) is the first reactive intermediate responsible
for the observed organic transformation. Furthermore, our computational
studies suggest a stepwise reaction mechanism based on a hydrogen
atom abstraction pathway, which is more energetically feasible than
many other possible pathways including β-hydride elimination,
single electron transfer, hydrogen atom transfer, oxidative addition/reductive
elimination, and σ-bond metathesis.
%I ACS Publications