Put a ring on it! The arylation of aliphatic alcohols and hydroxide with diaryliodoniumsalts, to give alkyl aryl ethers and diaryl ethers, has been studied using experimental techniques and DFT calculations. Aryne formation and alcohol oxidation pathways were observed in parallel to arylation, and additives to avoid by-product formation originating from arynes have been found. A novel, direct nucleophilic
A New and Efficient Hypervalent Iodine−Benzyne Precursor, (Phenyl)[<i>o</i>-(trimethylsilyl)phenyl]iodonium Triflate: Generation, Trapping Reaction, and Nature of Benzyne
the reaction in the presence of furan indicates a quantitative generation of benzyne and its efficient capture by the furan. Similarly, methylbenzynes (22 and 27) are efficiently generated from the corresponding methyl-substituted (trimethylsilyl)phenyliodonium triflates (12 and 13). The preparation of the hypervalent iodine−benzyne precursors, the generation of benzynes, the trapping reactions, and
Transition metal-free N-arylation of secondary amides through iodonium salts as aryne precursors
作者:Ming Wang、Zhijian Huang
DOI:10.1039/c6ob01649a
日期:——
By using a diaryliodonium salt as a benzyne precursor, a transition metal-freeapproach for N-arylation of secondary amides is developed. This novel benzyne precursor, which can be prepared easily by a one step process from an aryl iodide, shows different reactivities with previous benzyne precursors in the N-arylation reaction. Mechanistic studies confirm the involvement of benzyne species (generated
An alternative method for generating arynes from ortho-silylaryl triflates using cesium carbonate and 18-crown-6 is reported. The method was efficiently applied to a variety of reactions between several arynes and arynophiles. We also demonstrated that the efficiency of aryne generation is significantly affected by the alkali metal countercation of the carbonate.
Lewis Base‐Catalyzed Cycloaddition of Heterocyclic Alkenes with 2,2,2‐Trifluorodiazoethane (CF
<sub>3</sub>
CHN
<sub>2</sub>
): Access to Trifluoromethylated Pyrazolines and Pyrazoles
作者:Tingting Cao、Zhen Yang、Yunfang Sun、Nannan Zhao、Shan Lu、Jing Zhang、Lei Wang
DOI:10.1002/ejoc.202100521
日期:2021.6.7
An efficient Lewis base catalytic protocol to biologically important trifluoromethylated pyrazolines and pyrazoles is developed through [3+2] triazene-heterocycilc alkene cycloaddition reactions of an array of oxa-/aza-benzonorbornadienes and coumarins with CF3CHN2. This approach features good functional group tolerance and scaffold diversity. Synthetic utility of the protocol is highlighted by late-stage