42069-01-2Relevant academic research and scientific papers
Cobalt-catalyzed cross-coupling reactions of aryl- And alkylaluminum derivatives with (hetero)aryl and alkyl bromides
Dilauro, Giuseppe,Messa, Francesco,Bona, Fabio,Perrone, Serena,Salomone, Antonio
supporting information, p. 10564 - 10567 (2021/10/19)
A simple cobalt complex, such as Co(phen)Cl2, turned out to be a highly efficient and cheap precatalyst for a host of cross-coupling reactions involving aromatic and aliphatic organoaluminum reagents with aryl, heteroaryl and alkyl bromides. New C(sp2)-C(sp2) and C(sp2)-C(sp3) bonds were formed in good to excellent yields and with high chemoselectivity, under mild reaction conditions.
Redox inactive metal ion triggered N-dealkylation by an iron catalyst with dioxygen activation: A lesson from lipoxygenases
Zhang, Jisheng,Wang, Yujuan,Luo, Nengchao,Chen, Zhuqi,Wu, Kangbing,Yin, Guochuan
, p. 9847 - 9859 (2015/06/08)
Utilization of dioxygen as the terminal oxidant at ambient temperature is always a challenge in redox chemistry, because it is hard to oxidize a stable redox metal ion like iron(iii) to its high oxidation state to initialize the catalytic cycle. Inspired by the dioxygenation and co-oxidase activity of lipoxygenases, herein, we introduce an alternative protocol to activate the sluggish iron(iii) species with non-redox metal ions, which can promote its oxidizing power to facilitate substrate oxidation with dioxygen, thus initializing the catalytic cycle. In oxidations of N,N-dimethylaniline and its analogues, adding Zn(OTf)2 to the [Fe(TPA)Cl2]Cl catalyst can trigger the amine oxidation with dioxygen, whereas [Fe(TPA)Cl2]Cl alone is very sluggish. In stoichiometric oxidations, it has also been confirmed that the presence of Zn(OTf)2 can apparently improve the electron transfer capability of the [Fe(TPA)Cl2]Cl complex. Experiments using different types of substrates as trapping reagents disclosed that the iron(iv) species does not occur in the catalytic cycle, suggesting that oxidation of amines is initialized by electron transfer rather than hydrogen abstraction. Combined experiments from UV-Vis, high resolution mass spectrometry, electrochemistry, EPR and oxidation kinetics support that the improved electron transfer ability of iron(iii) species originates from its interaction with added Lewis acids like Zn2+ through a plausible chloride or OTf- bridge, which has promoted the redox potential of iron(iii) species. The amine oxidation mechanism was also discussed based on the available data, which resembles the co-oxidase activity of lipoxygenases in oxidative dealkylation of xenobiotic metabolisms where an external electron donor is not essential for dioxygen activation.
A general method for N-methylation of amines and nitro compounds with dimethylsulfoxide
Jiang, Xue,Wang, Chao,Wei, Yawen,Xue, Dong,Liu, Zhaotie,Xiao, Jianliang
supporting information, p. 58 - 63 (2014/01/17)
DMSO methylates a broad range of amines in the presence of formic acid, providing a novel, green and practical method for amine methylation. The protocol also allows the one-pot transformation of aromatic nitro compounds into dimethylated amines in the presence of a simple iron catalyst. Not just a solvent: DMSO methylates a broad range of amines in the presence of formic acid, providing a novel, green and practical method for amine methylation. The protocol also allows the one-pot transformation of aromatic nitro compounds into dimethylated amines in the presence of a simple iron catalyst. Copyright
Electrophilic fluorination of N,N-dimethylaniline, N,N-dimethylnaphthalen- 1-amine and 1,8-bis(dimethylamino)naphthalene with N-F reagents
Sorokin, Vladimir I.,Pozharskii, Alexander F.,Ozeryanskii, Valery A.
, p. 67 - 72 (2013/11/06)
Reaction of N,N-dimethylaniline, N,N-dimethylnaphthalen-1-amine and 1,8-bis(dimethylamino)- naphthalene (proton sponge) with 1-chloromethyl-4- fluorodiazonia-bicyclo[2.2.2]octane bis(tetrafluoroborate) (Selectfluor) and N-fluorobenzenesulfonimide (NFSI) h
Oxidant-dependent Cu-catalyzed alkynylation and aminomethylation: C-H versus C-C cleavage in TMEDA
Shen, Qi,Zhang, Lei,Zhou, Yu-Ren,Li, Jian-Xin
, p. 6725 - 6728 (2013/11/19)
Oxidant-dependent Cu-catalyzed alkynylation and aminomethylation reactions have been achieved under facile and mild conditions. TMEDA coupled with various terminal alkynes via C-H bond cleavage in good yields using atmospheric oxygen as an oxidant. Switching from air to TBHP afforded aminomethylation products of terminal alkynes through C-C bond cleavage of TMEDA. The protocol provided a novel strategy to prepare bi/tridentate N-ligand.
Ultrasound induced, copper mediated homocoupling using polymer supported aryltrifluoroborates
Musolino, Bryan,Quinn, Michael,Hall, Kelly,Coltuclu, Vitali,Kabalka, George W.
, p. 4080 - 4082 (2013/07/25)
Using Dowex polymer supported aryltrifluoroborates, we are able to achieve homocoupling for a variety of compounds. The reactions were completed in 6 h, while producing high yields of the desired products. The reaction proceeds under mild conditions, using ultrasound as the energy source, copper acetate as the metal co-reactant, and aqueous ethanol as solvent.
Synthesis of N,N,N',N'-tetraalkylbenzidines through oxidative coupling of N,N-dialkylarylamines induced by SbCl5
Vitale, Paola,Di Nunno, Leonardo,Scilimati, Antonio
, p. 36 - 48 (2013/05/09)
The oxidative coupling to 4,4'-N,N,N',N'-tetraalkylbenzidines is the main reaction observed during a study on the reactivity of N,N-dialkylanilines with SbCl5. A possible reaction mechanism is presented and discussed in comparison with the N,N-dialkylanilines oxidative coupling achieved with other Lewis acids. ARKAT-USA, Inc.
Palladium catalytic systems with hybrid pyrazole ligands in C-C coupling reactions. Nanoparticles versus molecular complexes
Peral, Daniel,Gomez-Villarraga, Fernando,Sala, Xavier,Pons, Josefina,Carles Bayon,Ros, Josep,Guerrero, Miguel,Vendier, Laure,Lecante, Pierre,Garcia-Anton, Jordi,Philippot, Karine
, p. 475 - 489 (2013/03/14)
This paper reports the comparison of the chemoselectivity of two different Pd catalytic systems, namely molecular and colloidal systems, in C-C coupling reactions. For this purpose, new hybrid pyrazole derived ligands containing alkylether, alkylthioether or alkylamino moieties have been synthesized and used to form Pd(ii) complexes and to stabilize Pd nanoparticles (Pd NPs). With the aim of studying the coordination mode of the ligands and further to understand their role in catalysis, both types of Pd species were characterized by appropriate techniques. In C-C coupling reactions promoted by different Pd colloidal systems, several reports evidenced that active species are molecular catalysts leached from Pd NPs. The most important feature of this work relies on the differences observed in the output of C-C coupling reactions, depending on the colloidal or molecular nature of the catalyst employed. Thus, molecular systems carry out typical Suzuki-Miyaura cross-coupling, together with the dehalogenation of the substrate in different proportions. In contrast, Pd NPs catalyze either Suzuki-Miyaura or C-C homocoupling reactions depending on the haloderivative used. Interestingly, Pd NPs catalyze the quantitative dehalogenation of 4-iodotoluene. Differences observed in the chemoselectivity of these two catalytic systems support that reactions carried out with Pd NPs stabilized with the hybrid pyrazole ligands employed here take place on the surface of the colloids. The Royal Society of Chemistry 2013.
Negishi cross-coupling reaction catalyzed by an aliphatic, phosphine based pincer complex of palladium. biaryl formation via cationic pincer-type Pd IV intermediates
Gerber, Roman,Blacque, Olivier,Frech, Christian M.
experimental part, p. 8996 - 9003 (2011/10/31)
The aliphatic, phosphine-based pincer complex [(C10H 13-1,3-(CH2P(Cy2)2)Pd(Cl)] (1) is a highly active Negishi catalyst, enable to quantitatively couple various electronically activated, non-activated, deactivated, sterically hindered and functionalized aryl bromides with various diarylzinc reagents within short reaction times and low catalyst loadings. Experimental observations strongly indicate that a molecular mechanism is operative with initial chloride dissociation of 1 and formation of the cationic T-shaped 14e- complex [(C10H13-1,3-(CH2P(C6H 11)2)2)Pd]+ (B), which undergoes oxidative addition of an aryl bromide (Ar′Br) to yield the cationic, penta-coordinated aryl bromide pincer complexes of type [(C10H 13-1,3-(CH2P(Cy2)2)Pd(Br) (aryl′)]+ (C) with the metal center in the oxidation state of +IV and the aryl unit in cis position relative to the aliphatic pincer core. Subsequent transmetalation with Zn(aryl)2 result in the cationic diaryl pincer complexes of type [(C10H13-1,3-(CH 2P(Cy2)2)Pd(aryl)(aryl′)]+ (D), which reductively eliminate the coupling products, thereby regenerating the catalyst. The neutral square planar aryl pincer complex - a possible key intermediate in the catalytic cycle - was found to be reversibly formed in the reaction mixture but is not involved in the catalytic mechanism. Similarly, palladium nanoparticles as the catalytically active form of 1 could have been excluded. The Royal Society of Chemistry 2011.
