103258-42-0Relevant academic research and scientific papers
Substituted functional olefins through lateral sequential lithiation/silylation/condensation of tertiary aromatic amides: A ligand for phosphane-free palladium-catalyzed Suzuki coupling reactions
Xu, Li-Wen,Chen, Xi-Huai,Shen, Hao,Deng, Yuan,Jiang, Jian-Xiong,Jiang, Kezhi,Lai, Guo-Qiao,Sheng, Chun-Qi
, p. 290 - 297 (2012)
An unprecedented lateral sequential lithiation/silylation/condensation of tertiary aromatic amides has been developed that provides an efficient method to build up functional olefins in good yields. In addition, we have established an efficient and simple method that involves UV/Vis, fluorescence, and NMR analyses, to detect the interaction between transition-metal salts and functional olefins containing tertiary amides. This has enabled a highly efficient palladium-catalyzed Suzuki coupling reaction in the presence of tertiary aromatic amide-derived olefin ligands to be developed. The best results were obtained by employing 2 mol-% Pd(OAc)2, 2 equiv. Cs 2CO3, a reaction temperature of 80 °C, dioxane as the solvent, and phosphane-free olefin 2d as ligand. Copyright
General Ambient Temperature Benzylic Metalations Using Mixed-Metal Li/K-TMP Amide
Manvar, Atul,Fleming, Patricia,O'Shea, Donal F.
, p. 8727 - 8738 (2015/09/15)
Highly regioselective benzylic metalations in hydrocarbon solvent have been achieved at rt and 0 °C using a mixed-metal Li/K-TMP amide comprised of KOtBu, BuLi, and 2,2,6,6,-tetramethylpiperidine (TMP(H)). Mixing of KOtBu, BuLi, and TMP(H) in heptane gave a solution of the base mixture which when used in deuterium labeling experiments confirmed the requirement of the three reagent components for both reactivity and selectivity. The reaction protocol is operationally straightforward and found to be applicable to a broad range of substrates. Upon generation of the metalated products, they are reacted in heptane at ambient temperature in a variety of synthetically useful ways. Illustrated examples include generation of the benzyltrimethylsilanes and α,α-bis(trimethylsilyl)toluenes reagents, which are bench-stable surrogates of benzyl anions and α-silyl carbanions utilized for nucleophilic addition and Peterson olefination reactions. Direct C-C couplings mediated by 1,2-dibromoethane provided entries into bibenzyls and [2.2]metacyclophanes. Comparison of reaction outcomes with the same reactions carried out in THF at -78 °C showed no negative effects for conducting the reactions under these milder more user-friendly conditions.
1-(Dialkylamino)isobenzofurans: Generation and Use for Annelation of Aromatic Rings
Chen, Chin-Wen,Beak, Peter
, p. 3325 - 3334 (2007/10/02)
Three methods are reported for the generation of the heretofore unreported 1-(dialkylamino)isobenzofurans.These are (1) metal-catalyzed decomposition of an o-(diazomethyl)benzamide (9 to 3), (2) fluoride-induced α elimination of an o-benzamide (48 to 3), and (3) deprotonation of a cyclic imidate salt (51 to 3).The first two reactions are consistent with the intermediacy of a carbene.The precursors for all three approaches can be synthesized from tertiary benzamides by ortho-lithiation strategies.Reaction of the transient 1-(dialkylamino)isobenzofurans with dieneophiles in a ?4s + ?2s cycloaddition is the key step in a one-pot sequence that provides annelation of an aromatic ring by a 2,3-substituted 1-(dialkylamino)-4-hydroxycyclohex-1-ene ring.The sequence of formation of the 1-(dialkylamino)isobenzofuran, regio- and stereospecific cycloaddition, ring opening, and proton transfer, is illustrated by the preparations of 15-23, 32, and 33 from N,N-diisopropylbenzamides.The ring annelation is extended to naphthalene and pyridine rings to provide 40, 41, and 44, respectively.Transformations of annelated products to higher and lower oxidation states are reported.
