7029-31-4Relevant articles and documents
Three-Component Difunctionalization of Cyclohexenyl Triflates: Direct Access to Versatile Cyclohexenes via Cyclohexynes
Cho, Seoyoung,McLaren, E. J.,Wang, Qiu
supporting information, p. 26332 - 26336 (2021/11/10)
Difunctionalization of strained cyclic alkynes presents a powerful strategy to build richly functionalized cyclic alkenes in an expedient fashion. Herein we disclose an efficient and flexible approach to achieve carbohalogenation, dicarbofunctionalization, aminohalogenation and aminocarbonation of readily available cyclohexenyl triflates. We have demonstrated the novel use of zincate base/nucleophile system for effective formation of key cyclohexyne intermediates and selective addition of various carbon and nitrogen nucleophiles. Importantly, leveraging the resulting organozincates enables the incorporation of a broad range of electrophilic partners to deliver structurally diverse cyclohexene motifs. The importance and utility of this method is also exemplified by the modularity of this approach and the ease in which even highly complex polycyclic scaffolds can be accessed in one step.
Cobalt-Catalyzed α-Arylation of Substituted α-Bromo α-Fluoro β-Lactams with Diaryl Zinc Reagents: Generalization to Functionalized Bromo Derivatives
Br?se, Stefan,Chen, Hi-Yung,Cossy, Janine,Koch, Vanessa,Lei, Aiwen,Lorion, Mélanie M.,Nieger, Martin
supporting information, p. 13163 - 13169 (2020/09/23)
A cobalt-catalyzed cross-coupling of α-bromo α-fluoro β-lactams with diarylzinc or diallylzinc reagents is herein disclosed. The protocol proved to be general, chemoselective and operationally simple allowing the C4 functionalization of β-lactams. The substrate scope was expanded to α-bromo lactams and amides, α-bromo lactones and esters as well as N- and O-containing heterocycles.
One-pot Negishi cross-coupling reaction of aryldiazonium salts via Ni catalysis induced by visible-light
Wang, Lianjun,Liu, Gao
, (2019/08/29)
Visible-light induced catalysis is of high interest for its mild and environmentally benign properties. Herein, a general Ni catalysis accelerated by visible-light was successfully developed for one-pot Negishi coupling reactions at room temperature in a short reaction time (2Zn generated in situ from Grignard reagents and ZnBr2. This protocol provides a convenient access to C–C bond formation for important biaryl components. It tolerates various functional groups, and Hammett study illuminates the possiblility of Ni(III)/Ni(I) redox catalytic cycle.
Iron-Catalyzed Difluoromethylation of Arylzincs with Difluoromethyl 2-Pyridyl Sulfone
Miao, Wenjun,Zhao, Yanchuan,Ni, Chuanfa,Gao, Bing,Zhang, Wei,Hu, Jinbo
supporting information, p. 880 - 883 (2018/02/07)
We report the first iron-catalyzed difluoromethylation of arylzincs with difluoromethyl 2-pyridyl sulfone via selective C-S bond cleavage. This method employs the readily available, bench-stable fluoroalkyl sulfone reagent and inexpensive iron catalyst, allowing facile access to structurally diverse difluoromethylated arenes at low temperatures. The experiment employing a radical clock indicates the involvement of radical species in this iron-catalyzed difluoromethylation process.
Decarboxylative Negishi Coupling of Redox-Active Aliphatic Esters by Cobalt Catalysis
Liu, Xu-Ge,Zhou, Chu-Jun,Lin,Han, Xiang-Lei,Zhang, Shang-Shi,Li, Qingjiang,Wang, Honggen
supporting information, p. 13096 - 13100 (2018/09/21)
A cobalt-catalyzed decarboxylative Negishi coupling reaction of redox-active aliphatic esters with organozinc reagents was developed. The method enabled efficient alkyl–aryl, alkyl–alkenyl, and alkyl–alkynyl coupling reactions under mild reaction conditions with no external ligand or additive needed. The success of an in situ activation protocol and the facile synthesis of the drug molecule (±)-preclamol highlight the synthetic potential of this method. Mechanistic studies indicated that a radical mechanism is involved.
Exploiting Synergistic Effects in Organozinc Chemistry for Direct Stereoselective C-Glycosylation Reactions at Room Temperature
Hernán-Gómez, Alberto,Orr, Samantha A.,Uzelac, Marina,Kennedy, Alan R.,Barroso, Santiago,Jusseau, Xavier,Lemaire, Sébastien,Farina, Vittorio,Hevia, Eva
supporting information, p. 10630 - 10634 (2018/08/01)
Pairing a range of bis(aryl) zinc reagents ZnAr2 with the stronger Lewis acidic [(ZnArF2)] (ArF=C6F5), enables highly stereoselective cross-coupling between glycosyl bromides and ZnAr2 without the use of a transition metal. Reactions occur at room temperature with excellent levels of stereoselectivity, where ZnArF2 acts as a non-coupling partner although its presence is crucial for the execution of the C(sp2)–C(sp3) bond formation process. Mechanistic studies have uncovered a unique synergistic partnership between the two zinc reagents, which circumvents the need for transition-metal catalysis or forcing reaction conditions. Key to the success of the coupling is the avoidance of solvents that act as Lewis bases versus diarylzinc compounds (e.g. THF).
Organozinc-Mediated Direct C?C Bond Formation via C?N Bond Cleavage of Ammonium Salts
Wang, Dong-Yu,Morimoto, Koki,Yang, Ze-Kun,Wang, Chao,Uchiyama, Masanobu
supporting information, p. 2554 - 2557 (2017/09/25)
We report a direct cross-coupling reaction between diarylzinc (Ar2Zn) and aryltrimethylammonium salts (ArNMe3 +??OTf) in the presence of LiCl, via C?N bond cleavage. The reaction takes place smoothly upon heating in THF without any external catalyst, enabling an efficient and chemoselective formation of biaryl products. Mechanistic studies indicate that the reaction proceeds through a single electron transfer route.
Copper-Catalyzed Negishi Coupling of Diarylzinc Reagents with Aryl Iodides
Thapa, Surendra,Vangala, Adarsh S.,Giri, Ramesh
, p. 504 - 511 (2016/02/14)
We report an efficient copper(I) iodide catalyzed cross-coupling of diarylzinc reagents with aryl iodides. The reaction proceeds under ligand-free conditions at low catalyst loading (5 mol%) and tolerates a variety of functional groups.
Catalytic cycle for palladium-catalyzed decarbonylative trifluoromethylation using trifluoroacetic esters as the CF3 source
Maleckis, Ansis,Sanford, Melanie S.
, p. 2653 - 2660 (2014/06/10)
This paper demonstrates a catalytic cycle for Pd-catalyzed decarbonylative trifluoromethylation using trifluoroacetic esters as CF3 sources. The proposed cycle consists of four elementary steps: (1) oxidative addition of a trifluoroacetic ester to Pd0, (2) CO deinsertion from the resulting trifluoroacyl PdII complex, (3) transmetalation of a zinc aryl to PdII, and (4) aryl-CF3 bond-forming reductive elimination. The use of RuPhos as the supporting ligand enables each of these steps to proceed under mild conditions (3 sources.
Nickel-catalyzed direct addition of diorganozinc reagents to phthalimides: Selective formation of gamma-hydroxylactams
Dennis, Joseph M.,Calyore, Catherine M.,Sjoholm, Jessica S.,Lutz, J. Patrick,Gair, Joseph J.,Johnson, Jeffrey B.
supporting information, p. 2567 - 2570 (2013/12/04)
The nickel-catalyzed addition of diorganozinc reagents to phthalimides proceeds with excellent selectivity to provide 3-substituted-3- hydroxyisoindolin-1-one products. These 3-hydroxy-γ-lactams are produced cleanly in high yield with numerous examples of imide substitution and a broad range of diorganozinc reagents that are prepared and utilized without purification. Georg Thieme Verlag Stuttgart · New York.
