- Synthesis and structure of group 4 symmetric amidinate complexes and their reactivity in the polymerization of α-olefins
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The steric properties of various nitrogen substituents on amidines were tuned in order to obtain group 4 mono- and bis(amidinate) dimethylamido or chloride complexes. The amidinate dimethylamido and chloride complexes were prepared, and their solid-state
- Elkin, Tatyana,Kulkarni, Naveen V.,Tumanskii, Boris,Botoshansky, Mark,Shimon, Linda J. W.,Eisen, Moris S.
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- Synthesis and structural studies of nickel(II)- and copper(II)-N,N′-diarylformamidine dithiocarbamate complexes as antimicrobial and antioxidant agents
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A series of six N′N-diarylformamidine dithiocarbamate ligands and their metal complexes of Cu(II) and Ni(II) chloride salts have been synthesized. Three symmetrical, N,N′-bis(2,6-dimethylphenyl)formamidine dithiocarbamate (DL1), N,N′-bis(2,6-disopropylphe
- Oladipo, Segun D.,Omondi, Bernard,Mocktar, Chunderika
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- Introduction of azetidinimine skeleton on C60
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The azacyclobutane structure is introduced into C60 fullerene using a photochemical reaction with formamidines. Three azetidinofullerenes (2c-2e) were synthesized; their molecular structures were characterized using 1H, 13
- Ueda, Nobuaki,Nikawa, Hidefumi,Takano, Yuta,Ishitsuka, Midori O.,Tsuchiya, Takahiro,Akasaka, Takeshi
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- Zn(ii) and Cu(ii) formamidine complexes: Structural, kinetics and polymer tacticity studies in the ring-opening polymerization of ?-caprolactone and lactides
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Treatment of N,N′-bis(2,6-dimethylphenyl)formamidine (L1), N,N′-bis(2,6-diisopropylphenyl)formamidine (L2), and N,N′-dimesitylformamidine (L3) with Zn(OAc)2·2H2O or Cu(OAc)2·H2O produced the corresponding Zn(ii)
- Akpan, Ekemini D.,Ojwach, Stephen O.,Omondi, Bernard,Nyamori, Vincent O.
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- Co(III) N,N′-diarylformamidine dithiocarbamate complexes: Synthesis, characterization, crystal structures and biological studies
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Three symmetric N,N-diarylformamidine dithiocarbamates, N,N′-bis(2,6-dimethylphenyl)formamidine dithiocarbamate (DTL1), N,N′-bis(2,6-disopropylphenyl)formamidine dithiocarbamate (DTL2) and N,N′-dimesitylformamidine dithiocarbamate (DTL3), and three unsymm
- Oladipo, Segun D.,Omondi, Bernard,Mocktar, Chunderika
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- Synthesis and Structural Characterization of Some New Magnesium Formamidinates
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[Mg(Form)2(THF)] [Form = bis(2,6-dimethylphenyl)formamidinate (XylForm) (1), bis(2,6-diethylphenyl)formamidinate, (EtForm) (2), bis(2,6-diisopropylphenyl)formamidinate (DippForm) (3)] are conveniently synthesized by treating bis(2,6-dimethylphe
- Cole, Marcus L.,Junk, Peter C.
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- Predicting molecular isomerism of symmetrical and unsymmetrical: N, N ′-diphenyl formamidines in the solid-state: Crystal structure, Hirshfeld surface analysis, pairwise interaction energy, and Δ H fusionand Δ S fusioncorrelations
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Eight N,N′-diphenylformamidines with the general formula [N-(Ar),N′-(Ar′)] were synthesized and characterized using spectroscopic and analytical techniques. Four were symmetrical (Ar = Ar′) while the other four were unsymmetrical (Ar ≠ Ar′). Five of the c
- Bongoza, Unathi,Omondi, Bernard,Zamisa, Sizwe J.
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- Impact of Electronic and Steric Changes of Ligands on the Assembly, Stability, and Redox Activity of Cu4(μ4-S) Model Compounds of the CuZ Active Site of Nitrous Oxide Reductase (N2OR)
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Model compounds have been widely utilized in understanding the structure and function of the unusual Cu4(μ4-S) active site (CuZ) of nitrous oxide reductase (N2OR). However, only a limited number of model compounds that mimic both structural and functional features of CuZ are available, limiting insights about CuZ that can be gained from model studies. Our aim has been to construct Cu4(μ4-S) clusters with tailored redox activity and chemical reactivity via modulating the ligand environment. Our synthetic approach uses dicopper(I) precursor complexes (Cu2L2) that assemble into a Cu4(μ4-S)L4 cluster with the addition of an appropriate sulfur source. Here, we summarize the features of the ligands L that stabilize precursor and Cu4(μ4-S) clusters, along with the alternative products that form with inappropriate ligands. The precursors are more likely to rearrange to Cu4(μ4-S) clusters when the Cu(I) ions are supported by bidentate ligands with 3-atom bridges, but steric and electronic features of the ligand also play crucial roles. Neutral phosphine donors have been found to stabilize Cu4(μ4-S) clusters in the 4Cu(I) oxidation state, while neutral nitrogen donors could not stabilize Cu4(μ4-S) clusters. Anionic formamidinate ligands have been found to stabilize Cu4(μ4-S) clusters in the 2Cu(I):2Cu(II) and 3Cu(I):1Cu(II) states, with both the formation of the dicopper(I) precursors and subsequent assembly of clusters being governed by the steric factor at the ortho positions of the N-aryl substituents. Phosphaamidinates, which combine a neutral phosphine donor and an anionic nitrogen donor in the same ligand, form multinuclear Cu(I) clusters unless the negative charge is valence-trapped on nitrogen, in which case the resulting dicopper precursor is unable to rearrange to a multinuclear cluster. Taken together, the results presented in this study provide design criteria for successful assembly of synthetic model clusters for the CuZ active site of N2OR, which should enable future insights into the chemical behavior of CuZ
- Hsu, Chia-Wei,Iniguez, Sarah J.,Johnson, Brittany J.,Mankad, Neal P.,Rathnayaka, Suresh C.
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p. 6496 - 6507
(2020/05/01)
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- The p: K a values of N-aryl imidazolinium salts, their higher homologues, and formamidinium salts in dimethyl sulfoxide
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A series of imidazolinium salts, their six-, seven- A nd eight-membered homologues, and the related formamidinium salts were prepared, and their pKa values were determined in DMSO at 25 °C using the bracketing indicator method. The effect of each type of structural variation on the acidity of each salt was considered, particularly noting the importance of ring size and the effect of the steric and electronic nature of the N-aryl substituents. The effect of a cyclic structure was also probed through comparing the cyclic systems with the corresponding formamidinium salts, noting the importance of conformational flexibility in the latter cases. Along with allowing choice of appropriate bases for deprotonation of these species, it is anticipated that the data presented will aid in the understanding of the nucleophilicity, and potentially catalytic efficacy, of the corresponding carbenes.
- Cole, Marcus L.,Dunn, Michelle H.,Harper, Jason B.,Konstandaras, Nicholas,Luis, Ena T.
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supporting information
p. 1910 - 1917
(2020/03/23)
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- Gold(I) Complexes Stabilized by Nine- and Ten-Membered N-Heterocyclic Carbene Ligands
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Nine- and ten-membered N-heterocyclic carbene (NHC) ligands have been developed and for the first time their gold(I) complexes were synthesized. The protonated NHC pro-ligands 2 a–h were prepared by the reaction of readily available N,N′-diarylformamidines with bis-electrophilic building blocks, followed by anion exchange. In situ deprotonation of the tetrafluoroborates 2 a–h with tBuOK in the presence of AuCl(SMe2) provided fast access to NHC-gold(I) complexes 3–10. These new NHC-gold(I) complexes show very good catalytic activity in a cycloisomerization reaction (0.1 mol % catalyst loading, up to 100 % conversion) and their solid-state structures reveal high steric hindrance around the metal atom (%Vbur up to 53.0) which is caused by their expanded-ring architecture.
- Cervantes-Reyes, Alejandro,Rominger, Frank,Rudolph, Matthias,Hashmi, A. Stephen K.
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supporting information
p. 11745 - 11757
(2019/08/20)
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- FLUORINE-SUBSTITUTED NITROGEN-CONTAINING HETEROCYCLIC COMPOUND, AND METHOD FOR PRODUCING THE SAME
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PROBLEM TO BE SOLVED: To provide a new fluorine-substituted nitrogen-containing heterocyclic compound. SOLUTION: The present invention provides a compound represented by formula (1) or a salt thereof [where A is CRp, carbene carbon, or C=RA; --- is a double bond if A is CRp, while it is a single bond if A is carbene carbon; RA is O, S, or NR; Rp is a hydrogen atom or an organic group; each R is the same or different every time it occurs and represents a hydrogen atom or an organic group; RX is a hydrogen atom, a fluorine atom, a chlorine atom, Rf, or ORf; and Rf is a fluoroalkyl group]. SELECTED DRAWING: None COPYRIGHT: (C)2018,JPOandINPIT
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Paragraph 0096
(2018/10/16)
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- A new water soluble copper N-heterocyclic carbene complex delivers mild O6G-selective RNA alkylation
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We show here that copper carbenes generated from diazo acetamides alkylate single RNAs, mRNAs, or pools of total transcriptome RNA, delivering exclusively alkylation at the O6 position in guanine (O6G). Although the reaction is effective with free copper some RNA fragmentation occurs, a problem we resolve by developing a novel water-stable copper N-heterocyclic carbene complex. Carboxymethyl adducts at O6G are known mutagenic lesions in DNA but their relevance in RNA biochemistry is unknown. As a case-in-point we re-examine an old controversy regarding whether O6G damage in RNA is susceptible to direct RNA repair.
- Rasale, Dnyaneshwar,Patil, Kiran,Sauter, Basilius,Geigle, Stefanie,Zhanybekova, Saule,Gillingham, Dennis
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supporting information
p. 9174 - 9177
(2018/08/23)
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- Dimethylamine as a Substrate in Hydroaminoalkylation Reactions
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Transition-metal-catalyzed hydroaminoalkylations of alkenes have made great progress over the last decade and are heading to become a viable alternative to the industrial synthesis of amines through hydroformylation of alkenes and subsequent reductive amination. In the past, one major obstacle of this progress has been an inability to apply these reactions to the most important amines, methylamine and dimethylamine. Herein, we report the first successful use of dimethylamine in catalytic hydroaminoalkylations of alkenes with good yields. We also report applicability for a variety of alkenes to show the tolerance of the reaction towards different functional groups. Additionally, we present a catalytic dihydroaminoalkylation reaction using dimethylamine, which has never been reported before.
- Bielefeld, Jens,Doye, Sven
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supporting information
p. 15155 - 15158
(2017/11/01)
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- Metal-free access of bulky: N, N ′-diarylcarbodiimides and their reduction: Bulky N, N ′-diarylformamidines
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A metal-free synthesis of symmetrical and unsymmetrical bulky N,N′-diaryl carbodiimides from the dehydrosulfurisation of their corresponding N,N′-diarylthiourea with 4-dimethylaminopyridine (DMAP) and iodine under mild reaction conditions with moderate to excellent yields has been established. In the literature, the classical method of dehydrosulfurisation of bulky N,N′-diarylthiourea to N,N′-diarylcarbodiimide has been reported using toxic metal oxide (HgO) and magnesium sulphate (MgSO4) under harsh reaction conditions. Furthermore, easy access to 1,3-disubstituted symmetric and unsymmetrical N,N′-diaryl formamidines involving the reaction of symmetrical and unsymmetrical N,N′-diaryl carbodiimides with sodium borohydride is described. The widely used method for the preparation of bulky N,N′-diaryl formamidines is the treatment of primary amines with triethylorthoformate in the presence of acid under high temperature reaction conditions.
- Peddarao, Thota,Baishya, Ashim,Barman, Milan Kr.,Kumar, Ajay,Nembenna, Sharanappa
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p. 7627 - 7636
(2016/09/12)
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- Structures, Electronics, and Reactivity of Strained Phosphazane Cages: A Combined Experimental and Computational Study
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A series of formamidine-bridged P2N2 cages have been prepared. Upon deprotonation, these compounds serve as valuable precursors to hybrid N-heterocyclic carbene ligands, whereas direct metalation gives rearranged dimetallic complexes as a result of cleavage of the formamidine bridge. The latter metal complexes contain an intact cyclophosphazane moiety that coordinates two distinct metal centers in a monodentate and a chelating fashion. A computational study has been carried out to elucidate the bonding within the P2N2 framework as well as the reactivity patterns. Natural bond orbital analysis indicates that the cage motif is poorly described by localized Lewis structures and that negative hyperconjugation effects govern the stability of the bicyclic framework. The donor capacity of the cyclophosphazane unit was assessed by inspection of the frontier molecular orbitals, highlighting the fact that π-back-donation from the metal fragments is crucial for effective metal-ligand binding.
- Roth, Torsten,Vasilenko, Vladislav,Wadepohl, Hubert,Wright, Dominic S.,Gade, Lutz H.
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supporting information
p. 7636 - 7644
(2015/08/11)
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- Multicomponent synthesis of 1-aryl 1,2,4-triazoles
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A multicomponent (single reactor) process for the synthesis of 1-aryl 1,2,4-triazoles was explored and developed. This transformation prepared the 1,2,4-triazole directly from anilines, amino pyridines, and pyrimidines. The reaction scope was explored with 21 different substrates, and the position of the nitrogen atoms in the newly formed ring was established by 15N labeling and NMR spectroscopy.
- Tam, Annie,Armstrong, Ian S.,La Cruz, Thomas E.
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supporting information
p. 3586 - 3589
(2013/08/23)
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- Expanded ring diaminocarbene palladium complexes: Synthesis, structure, and Suzuki-Miyaura cross-coupling of heteroaryl chlorides in water
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A series of new 6- and 7-membered N-heterocyclic carbene (NHC) complexes of palladium (NHC)Pd(cinn)Cl (cinn = cinnamyl = 3-phenylallyl) were synthesized and characterized structurally in the solid state. The influence of ring size (5, 6 or 7) and bulkiness of N-aryl substituents (Mes = 2,4,6-trimethylphenyl, or Dipp = 2,6-diisopropylphenyl) in carbenes on palladium catalysed Suzuki-Miyaura cross-coupling was revealed. Due to the unique stereoelectronic properties of expanded ring NHCs, a versatile, highly efficient green protocol of coupling of heteroaromatic chlorides and bromides with boronic acids has been developed. High quantitative yields of biaryls were achieved with water as solvent, under air, using low catalyst and phase transfer agent loadings, and with mild and environmentally benign base NaHCO3. The Royal Society of Chemistry 2013.
- Kolychev, Eugene L.,Asachenko, Andrey F.,Dzhevakov, Pavel B.,Bush, Alexander A.,Shuntikov, Viacheslav V.,Khrustalev, Victor N.,Nechaev, Mikhail S.
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p. 6859 - 6866
(2013/08/25)
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- Facile synthesis of hydroxyformamidines by the N-oxidation of their corresponding formamidines
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The N-oxidation of N,N-disubstituted amidines with MCPBA (m-chloroperoxibenzoic acid) affords a mild, rapid, and efficient route to the corresponding hydroxyamidines This novel synthetic route for the preparation of N,N-disubstituted hydroxyamidines provi
- Cibian, Mihaela,Langis-Barsetti, Sophie,Hanan, Garry S.
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supporting information; experimental part
p. 405 - 409
(2011/04/22)
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- An efficient synthesis of imidazolinium salts using vinyl sulfonium salts
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The synthesis of imidazolinium salts from the reaction of formamidines and (2-bromoethyl)diphenylsulfonium triflate is described. A variety of symmetrical and unsymmetrical imidazolinium triflate salts were synthesized in high yield in short reaction time
- McGarrigle, Eoghan M.,Fritz, Sven P.,Favereau, Ludovic,Yar, Muhammad,Aggarwal, Varinder K.
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supporting information; experimental part
p. 3060 - 3063
(2011/07/31)
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- Six- and seven-membered ring carbenes: Rational synthesis of amidinium salts, generation of carbenes, synthesis of Ag(I) and Cu(I) complexes
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Reactions of neat 1,3- and 1,4-dibromides with N,N′-diarylformamidines in the presence of diisopropylethylamine (DIPEA) afford corresponding amidinium salts in high yields (>80%). Six- and seven-membered ring amidinium salts bearing bulky Mes (2,4,6-Mesu
- Kolychev, Eugene L.,Portnyagin, Ivan A.,Shuntikov, Viacheslav V.,Khrustalev, Victor N.,Nechaev, Mikhail S.
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experimental part
p. 2454 - 2462
(2009/10/09)
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- A modular synthesis of highly substituted imidazolium salts
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A versatile and modular one-pot method for the preparation of differently substituted symmetrical and unsymmetrical imidazolium salts is reported, and 19 examples are given. In the key step, readily available formamidines and α-halo ketones are coupled to give imidazolinium salts 3, followed by imidazolium salt formation by acylation-induced elimination. For many substitution patterns of the imidazolium salt products, this efficient strategy compares favorably with well-known processes in terms of yield, ease of synthesis, and robustness.
- Hirano, Keiichi,Urban, Slawomir,Wang, Congyang,Glorius, Frank
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supporting information; experimental part
p. 1019 - 1022
(2009/07/18)
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- A facile preparation of imidazolinium chlorides
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A process for the preparation of symmetric and unsymmetric imidazolinium chlorides that involves reaction of a formamidine with dichloroethane and a base (a) is described. This method makes it possible to obtain numerous imidazolinium chlorides under solvent-free reaction conditions and in excellent yields with purification by simple filtration. Alternatively, symmetric imidazolinium chlorides can be prepared directly in moderate yields from substituted anilines by utilizing half of the formamidine Intermediate as sacrificial base (b).
- Kuhn, Kevin M.,Grubbs, Robert H.
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supporting information; experimental part
p. 2075 - 2077
(2009/04/10)
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