256475-07-7Relevant articles and documents
(2-Ethylhexyl)sodium: A Hexane-Soluble Reagent for Br/Na-Exchanges and Directed Metalations in Continuous Flow
Annapureddy, Rajasekar Reddy,Harenberg, Johannes H.,Hoefer, Carla A.,Knochel, Paul,Weidmann, Niels,Wiegand, Alexander J.
supporting information, p. 14296 - 14301 (2021/05/07)
We report the on-demand generation of hexane-soluble (2-ethylhexyl)sodium (1) from 3-(chloromethyl)heptane (2) using a sodium-packed-bed reactor under continuous flow conditions. Thus, the resulting solution of 1 is free of elemental sodium and therefore suited for a range of synthetic applications. This new procedure avoids the storage of an alkylsodium and limits the handling of metallic sodium to a minimum. (2-Ethylhexyl)sodium (1) proved to be a very useful reagent and undergoes in-line Br/Na-exchanges as well as directed sodiations. The resulting arylsodium intermediates are subsequently trapped in batch with various electrophiles such as ketones, aldehydes, Weinreb-amides, imines, allyl bromides, disulfides and alkyl iodides. A reaction scale-up of the Br/Na-exchange using an in-line electrophile quench was also reported.
Binuclear Palladium Complex Immobilized on Mesoporous SBA-16: Efficient Heterogeneous Catalyst for the Carbonylative Suzuki Coupling Reaction of Aryl Iodides and Arylboronic Acids Using Cr(CO)6 as Carbonyl Source
Niakan, Mahsa,Asadi, Zahra,Emami, Mohammad
, p. 404 - 418 (2020/01/03)
Abstract: In this study, a binuclear palladium complex immobilized on the organo-functionalized SBA-16 was prepared and structurally characterized by routine techniques. Characterizations indicated that the mesostructure of SBA-16 was maintained after the immobilization of palladium complex. Then, the prepared nanomaterial was applied as a heterogeneous catalyst in the carbonylative Suzuki coupling reaction of aryl iodides with arylboronic acids using Cr(CO)6 as carbonyl source. The catalyst was efficiently promoted the coupling reactions of various aryl iodides and arylboronic acids to give the corresponding diaryl ketones in excellent yields. Moreover, the catalyst was readily recovered by filtration and could be reused for seven cycles without losing its structural integrity and catalytic activity. Graphic Abstract: [Figure not available: see fulltext.].
2-Methyltetrahydrofuran (2-MeTHF): A Green Solvent for Pd?NHC-Catalyzed Amide and Ester Suzuki-Miyaura Cross-Coupling by N?C/O?C Cleavage
Lei, Peng,Ling, Yun,An, Jie,Nolan, Steven P.,Szostak, Michal
supporting information, p. 5654 - 5660 (2019/11/16)
The palladium-NHC-catalyzed (NHC=N-heterocyclic carbene) Suzuki-Miyaura cross-coupling of amides and esters via highly chemoselective N?C(O) and O?C(O) cleavage with aryl boronic acids using green, sustainable and eco-friendly 2-methyltetrahydrofuran (2-MeTHF) is reported. A variety of amides and aryl esters were coupled with aryl boronic acids in high to excellent yields. This method employs commercially-available, air- and moisture-stable Pd(II) ?NHC precatalysts. Crucially, the use of 2-MeTHF leads to the highest TON reported to date in amide N?C(O) bond cross-coupling. This operationally-simple protocol was utilized in the synthesis a bioactive ketone intermediate, emphasizing the potential of 2-MeTHF as a green solvent in unconventional amide bond disconnection. Given the tremendous importance of amide bond cross-coupling strategies and the drive to maintain full sustainability in cross-coupling processes, we expect that the synthetic method will be of broad interest.
Efficient Synthesis of Diaryl Ketones by Nickel-Catalyzed Negishi Cross-Coupling of Amides by Carbon–Nitrogen Bond Cleavage at Room Temperature Accelerated by a Solvent Effect
Shi, Shicheng,Szostak, Michal
, p. 10420 - 10424 (2016/07/21)
The first Negishi cross-coupling of amides for the synthesis of versatile diaryl ketones by selective C?N bond activation under exceedingly mild conditions is reported. The cross-coupling was accomplished with bench-stable, inexpensive precatalyst [Ni(PPh3)2Cl2] that shows high functional-group tolerance and enables the synthesis of highly functionalized diaryl ketone motifs. The coupling occurred with excellent chemoselectivity favoring the ketone (cf. biaryl) products. Notably, this process represents the mildest conditions for amide N?C bond activation accomplished to date (room temperature, 10 min). Considering the versatile role of polyfunctional biaryl ketone linchpins in modern organic synthesis, availability, and excellent functional-group tolerance of organozinc reagents, this strategy provides a new platform for amide N?C bond/organozinc cross-coupling under mild conditions.
Photochemically promoted transition metal-free cross-coupling of acylsilanes with organoboronic esters
Ito, Kazuta,Tamashima, Hiroto,Iwasawa, Nobuharu,Kusama, Hiroyuki
supporting information; experimental part, p. 3716 - 3719 (2011/05/14)
Intermolecular carbon-carbon bond formation between acylsilanes and organoboronic esters was achieved by photoirradiation under almost neutral, transition metal-free conditions. In this reaction, siloxycarbenes generated by photoisomerization of acylsilanes reacted with boronic esters to give the formal B-C bond insertion intermediates, which underwent unique rearrangement to afford the cyclic α-alkoxyboronic esters. Acidic treatment of the resulting crude products under air furnished the cross-coupled ketones in good yields.
A general synthesis of diarylketones by means of a three-component cross-coupling of aryl and heteroaryl bromides, carbon monoxide, and boronic acids
Neumann, Helfried,Brennfuehrer, Anne,Beller, Matthias
experimental part, p. 3645 - 3652 (2009/04/11)
Pd(OAc)2/di-1-adamantyl-n-butylphosphine (cataCXium A) is highly active in the three-component Suzuki carbonylation and represents the most general catalyst system reported up to now. A broad range of aryl/heteroaryl bromides and aryl boronic acids can be coupled to the corresponding diarylketones at low catalyst loadings.
Reactions of 2-hydroxybenzophenones with Corey-Chaykovsky reagent
Chittimalla, Santhosh Kumar,Chang, Tsung-Che,Liu, Ting-Chun,Hsieh, Hsing-Pang,Liao, Chun-Chen
, p. 2586 - 2595 (2008/09/19)
A variety of 2-hydroxybenzophenones on reaction with Corey-Chaykovsky reagent underwent unprecedented rearrangements leading to 3-substituted benzofurans 8 and one-carbon homologated compounds 9 and 12. Compounds 9 could further be quantitatively transfor
Application of the catalytic friedel-crafts acylation reaction and regioselectivity correlations
Wilkinson, Mark C.,Saez, Fabienne,Wei, Lee Hon
, p. 1063 - 1066 (2007/10/03)
A correlation was found between electronic properties and regioselectivity in the Friedel-Crafts reaction of substituted phenylacetic and benzoic acids with anisole, utilising substoichiometric (down to 1 mol%) amounts of catalyst. Relative reactivities of selected catalysts for this reaction were also studied. Georg Thieme Verlag Stuttgart.
Synthesis of sterically hindered ortho-substituted tetraphenylethenes. Electronic effects in the McMurry olefination reaction
Chung, Mee-Kyung,Qi, Guizhong,Stryker, Jeffrey M.
, p. 1491 - 1494 (2007/10/03)
Contrary to literature consensus, the McMurry olefination reaction can be extended to the direct synthesis of sterically encumbered tetrakis(2- substituted) tetraphenylethenes from the corresponding 2,2′-disubstituted benzophenones. The reaction exploits
