87167-85-9Relevant academic research and scientific papers
Direct C-H α-Arylation of Enones with ArI(O2CR)2 Reagents
Sousa E Silva, Felipe Cesar,Van, Nguyen T.,Wengryniuk, Sarah E.
, p. 64 - 69 (2020/01/22)
α-Arylation of α,β-unsaturated ketones constitutes a powerful synthetic transformation. It is most commonly achieved via cross-coupling of α-haloenones, but this stepwise strategy requires prefunctionalized substrates and expensive catalysts. Direct enone C-H α-arylation would offer an atom- and step-economical alternative, but such reports are scarce. Herein we report the metal-free direct C-H arylation of enones mediated by hypervalent iodine reagents. The reaction proceeds via a reductive iodonium Claisen rearrangement of in situ-generated β-pyridinium silyl enol ethers. The aryl groups are derived from ArI(O2CCF3)2 reagents, which are readily accessed from the parent iodoarenes. The reaction is tolerant of a wide range of substitution patterns, and the incorporated arenes maintain the valuable iodine functional handle. Mechanistic investigations implicate arylation via an umpoled "enolonium" species and show that the presence of a β-pyridinium moiety is critical for the desired C-C bond formation.
Synthesis of Functionalized Monoaryl-λ3-iodanes through Chemo- and Site-Selective ipso-Substitution Reactions
Komami, Narumi,Matsuoka, Keitaro,Nakano, Ayako,Kojima, Masahiro,Yoshino, Tatsuhiko,Matsunaga, Shigeki
supporting information, p. 1217 - 1220 (2019/01/04)
Monoaryl-λ3-iodanes are potentially attractive arylating agents. They are generally synthesized from aryl iodides via oxidation, which can cause functional group incompatibility, especially when polyfunctionalized derivatives are desired. This work describes the direct synthesis of monoaryl-λ3-iodanes through a chemoselective ipso-substitution reaction of arylgermanes and arylstannanes with iodine tris(trifluoroacetate). The generated iodanes were converted to iodonium ylides or used for further transformations in one pot. The presented method enables the preparation of polyfunctionalized monoaryl-λ3-iodanes.
