38111-44-3Relevant academic research and scientific papers
Ultrasound assisted nitratobis(triphenyl phosphine) copper(I) catalyzed conjugate addition of alkyl or aryl bromides to α,β-unsaturated cyanoester
Pise, Ashok S.,Burungale, Arvind S.,Devkate, Santosh S.,Gawade, Ramesh B.,Jadhav, Sunil D.
, p. 348 - 352 (2019)
The α,β-unsaturated cyanoester was obtained from p-methoxy benzaldehyde and ethyl cyano acetate by reported method. The conjugated addition products were synthesized from alkyl or aryl bromides and α,β-unsaturated cyanoester in the presence of 10 mol % Cu(I) catalyst in high yields within 17-21 min under ultrasound irradiation.
Role of Electron-Deficient Olefin Ligands in a Ni-Catalyzed Aziridine Cross-Coupling to Generate Quaternary Carbons
Estrada, Jesús G.,Williams, Wendy L.,Ting, Stephen I.,Doyle, Abigail G.
supporting information, p. 8928 - 8937 (2020/05/13)
We previously reported the development of an electron-deficient olefin (EDO) ligand, Fro-DO, that promotes the generation of quaternary carbon centers via Ni-catalyzed Csp3-Csp3 cross-coupling with aziridines. By contrast, electronically and structurally similar EDO ligands such as dimethyl fumarate and electron-deficient styrenes afford primarily β-hydride elimination side reactivity. Only a few catalyst systems have been identified that promote the formation of quaternary carbons via Ni-catalyzed Csp3-Csp3 cross-coupling. Although Fro-DO represents a promising ligand in this regard, the basis for its superior performance is not well understood. Here we describe a detailed mechanistic study of the aziridine cross-coupling reaction and the role of EDO ligands in facilitating Csp3-Csp3 bond formation. This analysis reveals that cross-coupling proceeds by a Ni0/II cycle with a NiII azametallacyclobutane catalyst resting state. Turnover-limiting C-C reductive elimination occurs from a spectroscopically observable NiII-dialkyl intermediate bound to the EDO. Computational analysis shows that Fro-DO accelerates turnover limiting reductive elimination via LUMO lowering. However, it is no more effective than dimethyl fumarate at reducing the barrier to Csp3-Csp3 reductive elimination. Instead, Fro-DO's unique reactivity arises from its ability to associate favorably to NiII intermediates. Natural bond order second-order perturbation theory analysis of the catalytically relevant NiII intermediate indicates that Fro-DO binds to NiII through an additional stabilizing donor-acceptor interaction between its sulfonyl group and NiII. Design of new ligands to evaluate this proposal supports this model and has led to the development of a new and tunable ligand framework.
Fukuyama Cross-Coupling Approach to Isoprekinamycin: Discovery of the Highly Active and Bench-Stable Palladium Precatalyst POxAP
Tang, Shuang-Qi,Bricard, Jacques,Schmitt, Martine,Bihel, Frédéric
supporting information, p. 844 - 848 (2019/01/30)
An efficient and user-friendly palladium(II) precatalyst, POxAP (post-oxidative-addition precatalyst), was identified for use in Fukuyama cross-coupling reactions. Suitable for storage under air, the POxAP precatalyst allowed reaction between thioesters and organozinc reagents with turnover numbers of ～90000. A series of 23 ketones were obtained with yields ranging from 53 to 99%. As proof of efficacy, an alternative approach was developed for the synthesis of a key precursor of the natural product isoprekinamycin.
Palladium(II)/Copper(II)-Catalyzed C–H Sulfidation or Selenation of Arenes Leading to Unsymmetrical Sulfides and Selenides
Nishino, Kota,Tsukahara, Shouya,Ogiwara, Yohei,Sakai, Norio
supporting information, p. 1588 - 1593 (2019/02/09)
A novel palladium(II)/copper(II)-catalyzed sulfidation of the C–H bond in electron-rich arenes and in pentafluorobenzene with disulfides was developed. This catalytic system can be used to efficiently produce various types of either unsymmetrical aryl sulfides or alkyl aryl sulfides. The present protocol could also be applied to the direct preparation of unsymmetrical aryl selenides via C–H selenation.
Mechanochemical Activation of Zinc and Application to Negishi Cross-Coupling
Cao, Qun,Howard, Joseph L.,Wheatley, Emilie,Browne, Duncan L.
supporting information, p. 11339 - 11343 (2018/08/28)
A form independent activation of zinc, concomitant generation of organozinc species and engagement in a Negishi cross-coupling reaction via mechanochemical methods is reported. The reported method exhibits a broad substrate scope for both C(sp3)–C(sp2) and C(sp2)–C(sp2) couplings and is tolerant to many important functional groups. The method may offer broad reaching opportunities for the in situ generation organometallic compounds from base metals and their concomitant engagement in synthetic reactions via mechanochemical methods.
Generation and Cross-Coupling of Organozinc Reagents in Flow
Herath, Ananda,Molteni, Valentina,Pan, Shifeng,Loren, Jon
supporting information, p. 7429 - 7432 (2019/01/03)
A versatile flow synthesis method for in situ formation of organozinc reagents and subsequent cross-coupling with aryl halides and activated carboxylic acids is reported. Formation of organozinc reagents is achieved by pumping organic halides, in the presence of ZnCl2 and LiCl, through an activated Mg-packed column under flow conditions. This method provides efficient in situ formation of aryl, primary, secondary, and tertiary alkyl organozinc reagents, which are subsequently telescoped downstream to a Negishi or decarboxylative Negishi cross-coupling reaction. The described method offers access to a variety of C-C bond formations with organozinc reagents that are otherwise commercially unavailable or difficult to prepare under traditional batch reaction conditions.
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).
Cobalt-Catalyzed Oxidative Homocoupling of Arylzinc Species
Bourne-Branchu, Yann,Moncomble, Aurélien,Corpet, Martin,Danoun, Gregory,Gosmini, Corinne
, p. 3352 - 3356 (2016/09/12)
A novel procedure for the synthesis of functionalized symmetrical biaryl compounds is described. The reaction proceeds via the oxidative homocoupling of arylzinc species formed by cobalt catalysis in the presence of air or p-benzoquinone depending on the nature of the functional group.
Electron-deficient olefin ligands enable generation of quaternary carbons by Ni-catalyzed cross-coupling
Huang, Chung-Yang,Doyle, Abigail G.
supporting information, p. 5638 - 5641 (2015/05/20)
A Ni-catalyzed Negishi cross-coupling with 1,1-disubstituted styrenyl aziridines has been developed. This method delivers valuable β-substituted phenethylamines via a challenging reductive elimination that affords a quaternary carbon. A novel electron-deficient olefin ligand, Fro-DO, proved crucial for achieving high rates and chemoselectivity for C-C bond formation over β-H elimination. This ligand is easy to access, is stable, and presents a modular framework for reaction discovery and optimization. We expect that these attributes, combined with the fact that the ligands impart distinct electronic properties to a metal, will support the invention of new transformations not previously possible using established ligands.
α-C-Glycosides via syn Opening of 1,2-Anhydro Sugars with Organozinc Compounds in Toluene/n-Dibutyl Ether
Wagschal, Simon,Guilbaud, Johan,Rabet, Pauline,Farina, Vittorio,Lemaire, Sébastien
, p. 9328 - 9335 (2015/09/28)
The diastereoselective addition of organozinc species to 1,2-anhydro sugars in toluene/n-dibutyl ether solvent is reported. Compared to the existing methods, the reaction proceeds at 0 °C, and only a slight excess of nucleophile is required to achieve good yields. Scope was assessed with different O-protected glycals along with various nucleophiles (aryl, alkynyl). This methodology was applied to the synthesis of the α-anomer of canagliflozin.
