A direct C-2 methylation reaction of indoles bearing a readily removable N-2-pyrimidyl moiety as a site-specific directing group has been developed with a palladium catalyst. This reaction relied on the use of KF to promote efficient methylation. A moderate to good yield was achieved in a range of indole substrates.
Palladium-Assisted Regioselective C–H Cyanation of Heteroarenes Using Isonitrile as Cyanide Source
作者:Shuguang Xu、Xiaomei Huang、Xiaohu Hong、Bin Xu
DOI:10.1021/ol302070t
日期:2012.9.7
A palladium-catalyzedregioselectiveC–Hcyanation of heteroarenes was achieved using tert-butyl isocyanide as “CN” source, which provides a new and unique strategy for the preparation of (hetero)aryl nitriles. Indoles, pyrroles, and aromatic rings could be efficiently cyanated through C–Hbondactivation with high regioselectivity.
‡ These authors contributed equally Dedicated to Professor Dieter Enders Abstract A cationic ruthenium(II)-complex enabled unprecedented C–H methylations on indoles and pyrroles. The versatile catalyst proved to be widely applicable and delivered the methylated heteroarenes with excellent levels of positional selectivity and ample substrate scope. The robustness of the catalysts was reflected by the
Tandem Rh(III)-Catalyzed C–H Amination/Annulation Reactions: Synthesis of Indoloquinoline Derivatives in Water
作者:Liangliang Shi、Baiquan Wang
DOI:10.1021/acs.orglett.6b01234
日期:2016.6.17
Rh(III)-catalyzed synthetic method for indoloquinoline derivatives from readily available indoles and isoxazoles was developed. This annulation procedure undergoes tandem C–H activation, cyclization, and condensation steps. In this domino cyclization reaction, water is an efficient solvent. A catalytically competent five-membered rhodacycle has been isolated and characterized, thus revealing a key intermediate
The manganese-catalyzed α-fluoroalkenylation of arenes via C–Hactivation and C–F cleavage has been described. This protocol provides a very useful method for the synthesis of monofluoroalkenes with predominant unconventional E-isomer selectivity which complements the existing strategies for the access to these molecular architectures. In addition, the selectivity of β-defluorination in the catalytic