450412-29-0Relevant articles and documents
Photocyclodehydrofluorination
Li, Zhe,Twieg, Robert J.
supporting information, p. 15534 - 15539 (2015/11/03)
Mallory-type photocyclization involves a series of photoreactions of stilbenes, o-terphenyls and related derivatives, which undergo intramolecular cyclization via dihydrophenanthrene intermediates. In typical Mallory photocyclizations, oxidants are usually needed to produce the final phenanthrene-containing product. In the research described here, appropriately fluorinated stilbenes and o-terphenyls undergo ring closure and HF is eliminated. This photocyclodehydrofluorination (PCDHF) reaction is very useful to produce a wide range of selectively fluorinated polynuclear aromatic hydrocarbons that possess a phenanthrene (or heterocyclic analogue of phenanthrene) substructure. These fluorinated products are of great interest in various aspects of the materials science.
Ring opening of aziridines with ortho-bromophenyl metal reagents: synthesis of 2-substituted indolines
Michaelis, David J.,Dineen, Thomas A.
body text, p. 1920 - 1923 (2009/08/17)
Stabilized ortho-bromo phenyllithium reagents, generated via lithium-halogen exchange of aryl iodides, undergo regioselective ring opening of mono-substituted N-Boc, N-Cbz, and N-tosyl-protected aziridines in good to excellent yields. The resulting ortho-
Generation and suppression of 3-/4-functionalized benzynes using zinc ate base (TMP-Zn-ate): New approaches to multisubstituted benzenes
Uchiyama, Masanobu,Kobayashi, Yuri,Furuyama, Taniyuki,Nakamura, Shinji,Kajihara, Yumiko,Miyoshi, Tomoko,Sakamoto, Takao,Kondo, Yoshinori,Morokuma, Keiji
, p. 472 - 480 (2008/10/09)
We present full details of our new methods for preparing functionalized benzynes with lithium di-alkyl(2,2,6,6-tetramethylpiperidino)zincate (R 2Zn(TMP)Li) through deprotonative zincation as a key reaction. In this system, by choosing appropriate ligands for the zincate, either regioselective zincation of functionalized haloaromatics or the generation of substituted benzynes can be controlled in good yields with excellent chemoselectivity, using the same substrate. Zincation with tBu 2Zn(TMP)Li followed by electrophilic trapping or zincation with Me2Zn(TMP)Li followed by nucleophilic or diene trapping is shown to be a powerful tool for the chemoselective preparation of 1,2,3-/1,2,4- trisubstituted benzene derivatives. These methods offer far greater generality than previous methods for the synthesis of multifunctionalized benzenes. Computational/theoretical studies of the reaction mechanism of this unique benzyne formation indicated that preferential coordination of the dialkylzinc moiety of zincate to halogen is the reason for the reduced activation energy of the elimination, that is, for the formation of the benzyne. The role of the ligands on Zn in accelerating/decelerating the elimination is also discussed.