- Make It Green: Copper-Catalyzed Olefin Aziridination in Water with an Iminoiodonane
-
The copper complex Tp(CF3)2,BrCu(NCMe) efficiently catalyses the aziridination of olefins in water using PhI=NTs as the nitrene source, with identical activity than that observed when using dichloromethane as the solvent, under the same experim
- Borrego, Elena,Pérez, Pedro J.,Caballero, Ana
-
p. 5091 - 5095
(2021/12/09)
-
- A Dicopper Nitrenoid by Oxidation of a CuICuICore: Synthesis, Electronic Structure, and Reactivity
-
A dicopper nitrenoid complex was prepared by formal oxidative addition of the nitrenoid fragment to a dicopper(I) center by reaction with the iminoiodinane PhINTs (Ts = tosylate). This nitrenoid complex, (DPFN)Cu2(μ-NTs)[NTf2]2 (DPFN = 2,7-bis(fluorodi(2-pyridyl)methyl)-1,8-naphthyridine), is a powerful H atom abstractor that reacts with a range of strong C-H bonds to form a mixed-valence Cu(I)/Cu(II) μ-NHTs amido complex in the first example of a clean H atom transfer to a dicopper nitrenoid core. In line with this reactivity, DFT calculations reveal that the nitrenoid is best described as an iminyl (NR radical anion) complex. The nitrenoid was trapped by the addition of water to form a mixed-donor hydroxo/amido dicopper(II) complex, which was independently obtained by reaction of a Cu2(μ-OH)2 complex with an amine through a protonolysis pathway. This mixed-donor complex is an analogue for the proposed intermediate in copper-catalyzed Chan-Evans-Lam coupling, which proceeds via C-X (X = N or O) bond formation. Treatment of the dicopper(II) mixed donor complex with MgPh2(THF)2 resulted in generation of a mixture that includes both phenol and a previously reported dicopper(I) bridging phenyl complex, illustrating that both reduction of dicopper(II) to dicopper(I) and concomitant C-X bond formation are feasible.
- Desnoyer, Addison N.,Nicolay, Amélie,Ziegler, Micah S.,Lakshmi,Cundari, Thomas R.,Tilley, T. Don
-
supporting information
p. 7135 - 7143
(2021/05/31)
-
- Is the Electrophilicity of the Metal Nitrene the Sole Predictor of Metal-Mediated Nitrene Transfer to Olefins? Secondary Contributing Factors as Revealed by a Library of High-Spin Co(II) Reagents
-
Recent research has highlighted the key role played by the electron affinity of the active metal-nitrene/imido oxidant as the driving force in nitrene additions to olefins to afford valuable aziridines. The present work showcases a library of Co(II) reage
- Kalra, Anshika,Bagchi, Vivek,Paraskevopoulou, Patrina,Das, Purak,Ai, Lin,Sanakis, Yiannis,Raptopoulos, Grigorios,Mohapatra, Sudip,Choudhury, Amitava,Sun, Zhicheng,Cundari, Thomas R.,Stavropoulos, Pericles
-
p. 1974 - 1996
(2021/06/28)
-
- Manganese-catalyzed aziridination of olefins with chloramine-T in water and buffered aqueous solutions
-
A water-soluble, manganese-porphyrin complex was used to catalytically generate aziridines from olefins in moderate to good yields (up to 93%) upon optimization at room temperature and in aqueous media. Reactions using chloramine-T at slightly acidic to n
- Wolgemuth, Daniel K.,Elmore, Sydnee D.,Cope, James D.,Sheridan, Patrick E.,Stokes, Sean L.,Emerson, Joseph P.
-
-
- Ni-Catalyzed Carboxylation of Aziridines en Route to β-Amino Acids
-
A Ni-catalyzed reductive carboxylation of N-substituted aziridines with CO2 at atmospheric pressure is disclosed. The protocol is characterized by its mild conditions, experimental ease, and exquisite chemo- and regioselectivity pattern, thus unlocking a new catalytic blueprint to access β-amino acids, important building blocks with considerable potential as peptidomimetics.
- Davies, Jacob,Janssen-Müller, Daniel,Zimin, Dmitry P.,Day, Craig S.,Yanagi, Tomoyuki,Elfert, Jonas,Martin, Ruben
-
supporting information
p. 4949 - 4954
(2021/04/07)
-
- Zwitterion-Catalyzed Intermolecular Bromoesterifications
-
Intermolecular haloesterification is an important class of transformations. The resulting products are valuable building blocks. However, it is often necessary to use super-stoichiometric amount of acid in order to compensate the low reactivity. Herein, we report a zwitterion-catalyzed intermolecular bromoesterification using acid and olefin in an equimolar ratio. Mechanistic study revealed that the charge pair in the zwitterion works synergistically in activating both NBS and carboxylic acid.
- Ng, Wing-Hin,Hu, Rong-Bin,Lam, Ying-Pong,Yeung, Ying-Yeung
-
supporting information
p. 5572 - 5576
(2020/07/24)
-
- Synthesis of β-Phenethylamines via Ni/Photoredox Cross-Electrophile Coupling of Aliphatic Aziridines and Aryl Iodides
-
A photoassisted Ni-catalyzed reductive cross-coupling between tosyl-protected alkyl aziridines and commercially available (hetero)aryl iodides is reported. This mild and modular method proceeds in the absence of stoichiometric heterogeneous reductants and uses an inexpensive organic photocatalyst to access medicinally valuable β-phenethylamine derivatives. Unprecedented reactivity was achieved with the activation of cyclic aziridines. Mechanistic studies suggest that the regioselectivity and reactivity observed under these conditions are a result of nucleophilic iodide ring opening of the aziridine to generate an iodoamine as the active electrophile. This strategy also enables cross-coupling with Boc-protected aziridines.
- Steiman, Talia J.,Liu, Junyi,Mengiste, Amanuella,Doyle, Abigail G.
-
supporting information
p. 7598 - 7605
(2020/04/21)
-
- Metal-free cascade reactions of aziridines with arylalkynes and aryldiazoniums: Facile access to arylazopyrrolines
-
A novel and facile approach to synthesize arylazopyrroline scaffolds via metal-free cascade reactions of aziridines with arylalkynes and aryldiazoniums has been developed, providing access to a variety of 4-arylazo-2-pyrrolines in a highly concise fashion. This efficient process, which can be performed at the gram scale, enjoys operational simplicity and mild and metal-free conditions.
- Rong, Jing,Jiang, Hao,Wang, Sijing,Su, Zhenni,Wang, Huiyan,Tao, Chuanzhou
-
supporting information
p. 3149 - 3157
(2020/05/08)
-
- An Electron-Poor Dioxa-[2.1.1]-(2,6)-pyridinophane Ligand and Its Application in Cu-Catalyzed Olefin Aziridination
-
A novel macrocyclic 1,7-dioxa-[2.1.1]-(2,6)-pyridinophane ligand has been synthesized and crystallographically characterized. Two derived metal complexes, dichloropalladium(II) and chlorocopper(I), were prepared. In the palladium(II) complex LPdCl2/
- Yang, Fan,Ruan, Jiaheng,Zavalij, Peter Y.,Vedernikov, Andrei N.
-
-
- Regiodivergent and Stereospecific Aziridine Opening by Copper-Catalyzed Addition of Silicon Grignard Reagents
-
A stereospecific ring opening of various 2-aryl-substituted aziridines with silicon Grignard reagents under copper catalysis is reported. The regiochemical outcome is governed by the steric demand of the silicon nucleophile. The LiCl introduced with the m
- Yi, Hong,Oestreich, Martin
-
supporting information
p. 6505 - 6507
(2019/04/30)
-
- A bromo-capped diruthenium(i,i) N-heterocyclic carbene compound for in situ bromine generation with NBS: Catalytic olefin aziridination reactions
-
A bromo-capped metal-metal bonded diruthenium(i,i) complex Ru2(CO)4(PIN)2Br2 (1) (PIN = 1-isopropyl-3-(5,7-dimethyl-1,8-naphthyrid-2-yl)imidazol-2-ylidene) generates bromine with N-bromosuccinimide (NBS) at room temperature. Cycloalkene and stilbene are readily brominated by stoichiometric reactions with 1 and NBS. An analysis of the dibrominated products suggests the formation of cyclic bromonium intermediates indicating in situ Br2 generation. Complex 2, an iodide analogue of 1, is also synthesized. The reaction of 2 with N-iodosuccinimide releases I2, which is confirmed by the starch-iodine test. The catalytic utility of 1 is examined for the bromination of phenol. Catalyst 1, in combination with NBS and base, exhibits regioselectivity towards monobrominated products. Furthermore, efficient olefin aziridination is demonstrated utilizing catalyst 1 in the presence of NBS, K2CO3 and TsNH2.
- Sengupta, Gargi,Pandey, Pragati,De, Subhabrata,Ramapanicker, Ramesh,Bera, Jitendra K.
-
p. 11917 - 11924
(2018/09/10)
-
- Annelated Cyclobutanes by Fe-Catalyzed Cycloisomerization of Enyne Acetates
-
Cationic Fe complexes of the general type [(Ph3P)2Fe(CO)(NO)]X (X=BF4, BArF4) catalyze the redox-neutral cycloisomerization of 1,6- and 1,7-enyneacetates to afford bicyclic cyclobutanes under mild conditions in good yields and diastereoselectivities.
- Kramm, Frederik,Teske, Johannes,Ullwer, Franziska,Frey, Wolfgang,Plietker, Bernd
-
supporting information
p. 13335 - 13338
(2018/09/25)
-
- Achieving regio- and stereo-control in the fluorination of aziridines under acidic conditions
-
We developed an efficient fluorination protocol that converts easily accessible aziridines into β-fluoroamines, which are important motifs in biologically active molecules. In contrast with traditional fluorination approaches, DMPU-HF has shown both highe
- Okoromoba, Otome E.,Li, Zhou,Robertson, Nicole,Mashuta, Mark S.,Couto, Uenifer R.,Tormena, Cláudio F.,Xu, Bo,Hammond, Gerald B.
-
supporting information
p. 13353 - 13356
(2016/11/18)
-
- A population multi-Pulley method for the preparation of intermediates
-
The invention relates to a method for preparing a trandolapril intermediate in the field of biomedicines, i.e. a method for synthesizing (2S, 3aR, 7aS)-octahydroindole-2-carboxyl benzyl ester. Firstly, cyclohexene and chloramine T are taken as initial raw
- -
-
Paragraph 0026; 0072; 0073
(2016/10/09)
-
- Grafting of copper(II) Schiff base complex on functionalized multi-wall carbon nanotubes: Synthesis, characterization and catalytic aziridination of olefins
-
In this study, hydroxyl functionalized copper(II) Schiff-base; [Cu((OH)2-salophen)], [(OH)2-salophen] = (N,N-bis(4-hydroxysalicylidene) phenylene-1,2-diamine); has been covalently anchored on modified multi-wall carbon nanotubes (MWN
- Bazarganipour, Mehdi,Salavati-Niasari, Masoud
-
-
- Metal-free one-pot synthesis of 2-substituted and 2,3-disubstituted morpholines from aziridines
-
The metal-free synthesis of 2-substituted and 2,3-disubstituted morpholines through a one-pot strategy is described. A simple and inexpensive ammonium persulfate salt enables the reaction of aziridines with halogenated alcohols to proceed via an SN2-type ring opening followed by cyclization of the resulting haloalkoxy amine.
- Sun, Hongnan,Huang, Binbin,Lin, Run,Yang, Chao,Xia, Wujiong
-
supporting information
p. 524 - 529
(2015/06/08)
-
- Tandem aziridine ring opening-disulfide formation-reduction-Michael addition in one-pot mediated by tetrathiomolybdate
-
Abstract A detailed study of tetrathiomolybdate mediated tandem regio- and stereoselective ring opening of aziridine, disulfide formation, reduction of disulfide bond and Michael reaction in a one-pot operation is reported. This constitutes four reactions
- Sureshkumar, Devarajulu,Gunasundari, Thanikachalam,Chandrasekaran, Srinivasan
-
p. 7267 - 7281
(2015/08/24)
-
- A versatile tripodal Cu(I) reagent for C-N bond construction via nitrene-transfer chemistry: Catalytic perspectives and mechanistic insights on C-H aminations/amidinations and olefin aziridinations
-
A CuI catalyst (1), supported by a framework of strongly basic guanidinato moieties, mediates nitrene-transfer from PhI=NR sources to a wide variety of aliphatic hydrocarbons (C-H amination or amidination in the presence of nitriles) and olefins (aziridination). Product profiles are consistent with a stepwise rather than concerted C-N bond formation. Mechanistic investigations with the aid of Hammett plots, kinetic isotope effects, labeled stereochemical probes, and radical traps and clocks allow us to conclude that carboradical intermediates play a major role and are generated by hydrogen-atom abstraction from substrate C-H bonds or initial nitrene-addition to one of the olefinic carbons. Subsequent processes include solvent-caged radical recombination to afford the major amination and aziridination products but also one-electron oxidation of diffusively free carboradicals to generate amidination products due to carbocation participation. Analyses of metal- and ligand-centered events by variable temperature electrospray mass spectrometry, cyclic voltammetry, and electron paramagnetic resonance spectroscopy, coupled with computational studies, indicate that an active, but still elusive, copper-nitrene (S = 1) intermediate initially abstracts a hydrogen atom from, or adds nitrene to, C-H and C=C bonds, respectively, followed by a spin flip and radical rebound to afford intra- and intermolecular C-N containing products.
- Bagchi, Vivek,Paraskevopoulou, Patrina,Das, Purak,Chi, Lingyu,Wang, Qiuwen,Choudhury, Amitava,Mathieson, Jennifer S.,Cronin, Leroy,Pardue, Daniel B.,Cundari, Thomas R.,Mitrikas, George,Sanakis, Yiannis,Stavropoulos, Pericles
-
supporting information
p. 11362 - 11381
(2014/09/17)
-
- Aziridination of olefins with bromamine-T in presence of iodine as catalyst
-
A strategy for achieving synthesis of aziridine employing iodine catalysed aziridination of alkenes with bromamine-T as nitrene source has been described. Ethyl acetate has been found to be the most suitable solvent and the strategy has been extended to v
- Sharma, Chinta Mani,Kashyap, Bishwapran,Phukan, Prodeep
-
p. 750 - 753
(2014/07/07)
-
- Regioselective Ring-Opening Nucleophilic Addition of Aziridines through Photoredox Catalyst
-
A mild and efficient procedure was developed for the regioselective ring-opening nucleophilic addition reactions of aziridines via visible light photoredox catalysis, that provides a practical synthetic access to 1,2-bifunctional compounds. Furthermore, the regioselective synthesis of non-racemic amino ethers from chiral aziridine could also be achieved under mild conditions. Finally, a possible reaction mechanism was proposed and further supported by control experiments.
- Sun, Hongnan,Yang, Chao,Lin, Run,Xia, Wujiong
-
supporting information
p. 2775 - 2780
(2016/02/18)
-
- Intermolecular Alkene Aziridination: An Original and Efficient Cu I···CuI Dinuclear Catalyst Deriving from a Phospha-Amidinate Ligand
-
Mononuclear and dinuclear CuI complexes 1 and 2 derived from the phospha-amidinate ligands [tBu2P(NSiMe3) 2]- and [Ph2P(NSiMe3) 2]-, respectively, have been
- Nebra, Noel,Lescot, Camille,Dauban, Philippe,Mallet-Ladeira, Sonia,Martin-Vaca, Blanca,Bourissou, Didier
-
supporting information
p. 984 - 990
(2013/03/14)
-
- Nanocrystalline zinc peroxide mediated unprecedented nitrene transfer: An expeditious access to N-tosylaziridines
-
An unprecedented zinc peroxide (ZnO2) assisted synthetic strategy is reported for the synthesis of N-tosylaziridines from alkenes by using N-tosyliminotriphenylphosphorane (Ph3PNTs) as a nitrene transfer reagent under mild reaction conditions. The reaction of zinc peroxide with Ph3PNTs yielded a zinc oxaziridine intermediate which subsequently reacts with alkenes to give corresponding N-tosylaziridines in high to excellent yields. The Royal Society of Chemistry 2013.
- Verma, Sanny,Jain, Suman L.
-
p. 19830 - 19833
(2013/11/06)
-
- Synthesis of 1,4-benzoxazepine derivatives via a novel domino aziridine ring-opening and isocyanide-insertion reaction
-
A novel and efficient domino process has been developed for the synthesis of 1,4-benzoxazepine derivatives from a range of readily accessible N-tosylaziridines, 2-iodophenols and isocyanides. This process involves the aziridine ring-opening reaction with 2-iodophenol, followed by a palladium-catalyzed isocyanide-insertion reaction. This regioselective and high-yielding transformation could be extended to its application for the synthesis of natural products and biologically interesting heterocycles. Copyright
- Ji, Fei,Lv, Mei-Fang,Yi, Wen-Bin,Cai, Chun
-
p. 3401 - 3406
(2013/12/04)
-
- A rapid and simple method for quantitative aziridination from aminobrominated derivatives of olefins under solvent-free and mild conditions
-
The urea-catalyzed aziridination of 1,2-vicinal haloamines derived from aminohalogenation of olefins has been developed. This rapid and simple method was carried out by simply grinding the solid mixture of the substrate, K 2CO3 and c
- Wei, Junfa,Chen, Zhanguo,Gao, Yanni,Zhang, Peng,Wang, Chuanning,Zhao, Pengfei,Wang, Yun,Shi, Xianying
-
experimental part
p. 391 - 399
(2012/05/04)
-
- Half-sandwich scorpionates as nitrene transfer catalysts
-
Scorpionate complexes of the middle to late 3d transition metals [(L)M(NCMe)3](BF4)n (M = Mn, Fe, Co, Ni: 1 M, L = tris(3,5-dimethylpyrazol-1-yl)methane, TpmMe,Me, n = 2; 2M, L = tris(3-phenylpyrazol-1-yl)methane, TpmPh, n = 2; 3M except 3Mn, L = hydrotris(3,5-dimethylpyrazol-1-yl) borate, [TpMe,Me]-, n = 1; 4M, L = hydrotris(3-phenyl-5-methylpyrazol-1-yl)borate, [TpPh,Me] -, n = 1) were examined as catalysts for styrene aziridination and THF amination using phenyl-N-tosyliodinane as a nitrene donor. [(Tpm Me,Me)Fe(NCMe)3](BF4)2 (1 Fe) was identified as the most active catalyst, giving nearly quantitative nitrene transfer yields at 5 mol % loadings. The reactivity of 1Fe with a wider range of organic substrates was also explored, and a striking observation was strong selectivity for aromatic rather than benzylic amination for alkylaromatic substrates.
- Liang, Shengwen,Jensen, Michael P.
-
p. 8055 - 8058
(2013/02/22)
-
- Aziridination of Olefins
-
A process for aziridination of olefins using NaIO4/alkali metal bromide/H+/Chloramine-T combination in presence of dipolar aprotic solvent under ambient conditions to obtain aziridines is disclosed.
- -
-
Page/Page column 4-6
(2012/09/05)
-
- A rapid and facile method for the general synthesis of 3-aryl substituted 4,5,6,7-tetrahydro[1,2,3]triazolo[1,5-a]pyrazines and their ring fused analogues
-
We report a general and facile method that provides rapid entry into 3-aryl substituted 4,5,6,7-tetrahydro[1,2,3]triazolo[1,5-a]pyrazines and their ring fused analogues in one-pot under palladium-copper catalysis. The methodology utilises simple and easily available substrates of broad range. The applicability of this reaction for the synthesis of optically active products has been demonstrated. A plausible reaction mechanism has also been proposed.
- Chowdhury, Chinmay,Mukherjee, Sanjukta,Chakraborty, Biswajit,Achari, Basudeb
-
supporting information; scheme or table
p. 5856 - 5862
(2011/09/30)
-
- β-Elimination of an aziridine to an allylic amine: A mechanistic study
-
The base-induced rearrangement of aziridines has been examined using a combination of calculations and experiment. The calculations show that the substituent on nitrogen is a critical feature that greatly affects the favorability of both α-deprotonation,
- Morgan, Kathleen M.,Brown Jr., Garry,Pichon, Monique A.,Green, Geannette Y.
-
experimental part
p. 1144 - 1150
(2012/03/09)
-
- O-alkoxyphenyliminoiodanes: Highly efficient reagents for the catalytic aziridination of alkenes and the metal-free amination of organic substrates
-
Efficient nitrene precursors: Highly reactive iminoiodane-based nitrene precursors were prepared from ortho-alkoxyiodobenzenes. Owing to the presence of the ortho-substituent on the phenyl ring, these new iminoiodanes have excellent solubility in organic
- Yoshimura, Akira,Nemykin, Victor N.,Zhdankin, Viktor V.
-
supporting information; experimental part
p. 10538 - 10541
(2011/11/12)
-
- A facile noncatalytic pathway for the nitrene transfer process: Expeditious access to aziridines
-
A fast and efficient method has been developed for generation of sulfonyl nitrene from N,N-dibromo-p-toluenesulfonamide (TsNBr2) in the presence of a base without any catalyst. This method was applied to produce aziridines from different kinds of olefins within a short time in high yields. The Royal Society of Chemistry.
- Saikia, Indranirekha,Kashyap, Bishwapran,Phukan, Prodeep
-
supporting information; experimental part
p. 2967 - 2969
(2011/04/24)
-
- Catalyst-free regio- and stereospecific synthesis of β-sulfonamido dithiocarbamates: Efficient ring-opening reactions of N-tosyl aziridines by dialkyldithiocarbamates
-
Lord of the ring-opening! A metal-free strategy involving ring-opening of aziridines by the sodium salt of dialkyldithiocarbamate has been employed to give a variety of β-sulfonamido dithiocarbamates. The in situ generation of dialkyldithiocarbamates prov
- Alagiri, Kaliyamoorthy,Prabhu, Kandikere Ramaiah
-
supporting information; experimental part
p. 6922 - 6925
(2011/07/08)
-
- Ag(I)-catalyzed regioselective ring-opening of N -tosylaziridine and N -tosylazetidine with S -, O -, and N -nucleophiles and tethered dinucleophiles
-
[Ag(COD)2]PF6 catalyzes the ring-opening of N-tosylaziridines and -azetidines with alcohols, amines, thiols, and related tethered 1,2-ethane dinucleophiles. Initial rate studies and DFT-based evaluation of stepwise energetics suggest
- Bera, Milan,Pratihar, Sanjay,Roy, Sujit
-
supporting information; experimental part
p. 1475 - 1478
(2011/04/27)
-
- NaIO4/LiBr-mediated aziridination of olefins using chloramine-T
-
A new milder protocol for aziridination of a variety of olefins has been described. The process employs catalytic amount of sodium metaperiodate (NaIO4) as an oxidant and LiBr and chloramine-T as the bromine and nitrogen sources, respectively. Interestingly, the formation of aziridine products in all the cases studied takes place presumably through a process of 1,2-aminobromination of alkenes.
- Karabal, Pratibha U.,Chouthaiwale, Pandurang V.,Shaikh, Tanveer M.,Suryavanshi, Gurunath,Sudalai, Arumugam
-
experimental part
p. 6460 - 6462
(2011/01/03)
-
- Palladium-catalyzed domino ring-opening/carboxamidation reactions of N -tosyl aziridines and 2-iodothiophenols: A facile and efficient approach to 1,4-benzothiazepin-5-ones
-
A novel and efficient domino procedure has been developed for the synthesis of 1,4-benzothiazepin-5-ones from simple and readily accessible N-tosyl aziridines and o-iodothiophenols. This process involves aziridines ring-opening with o-iodothiophenols, followed by palladium-catalyzed intramolecular carboxamidation. The scope and limitation of this transformation have been investigated in detail by using various aziridines and o-iodothiophenols.
- Zeng, Fanlong,Alper, Howard
-
supporting information; experimental part
p. 5567 - 5569
(2011/02/23)
-
- Facile synthesis of oxazolidinones catalyzed by n-Bu4NBr 3/n-Bu4NBr directly from olefins, chloramine-T and carbon dioxide
-
A binary catalyst systemcomposed of n-Bu4NBr3/n-Bu4NBrwas developed for facile synthesis of 5-substituted 2-oxazolidinoneswith perfect regioselectivity in a single operation directly fromolefins, chloramine-T and CO2. The choice of efficient binary catalysts for two steps, i.e. aziridination and cycloaddition, and the optimization of reaction condition are keys to the one-pot synthesis of 5-substituted 2-oxazolidinones. A possiblemechanismfor the present one-pot synthesis of oxazolidinones was also proposed.
- Kong, De-Lin,He, Liang-Nian,Wang, Jin-Quan
-
experimental part
p. 992 - 995
(2010/11/16)
-
- Synthesis of copper(I) complexes of N-heterocyclic carbene-phenoxyimine/ amine ligands: Structures of mononuclear copper(II), mixed-valence copper(I)/(II), and copper(II) cluster complexes
-
Copper(I) bromide complexes (2a and 2b) of NHC-phenol-imine ligand precursors {3-[(1R,2R)-2-{[1-(3,5-di-tert-butyl-2-hydroxyphenyl)meth-(E)- ylidene] amino}cyclohexyl] -1-iso-propyl-4-phenyl-3H-imidazol-1-ium bromide (1a) and 3-[(1R,2R)-2-{[1-(2-hydroxyphenyl)meth-(E)-ylidene] amino}-cyclohexyl] -1-isopropyl-4-phenyl-3H-imidazol-1-ium bro-mide (1b), respectively} have been prepared. Complexes 2aand 2b exhibit copper coordination only through the carbenecarbon atom (C) and do not spontaneously eliminate HBr togive additional phenoxyimine (NO) bonds, which is attrib-uted to intramolecular hydrogen bonding. Crystallisation of2a and 2b gives 2a-and 2b-, respectively, that contain (C) copper(I) bromide and (NO)2 copper(II) coordination. Com-plex 2b-also exhibits intermolecular CuIBr interactions giv-ingaCu2Br2 bridge that links two molecules of 2b resulting in an ellipse motif. Reduction of the ligand precursor iminegroup of 1a allows synthesis of silver(I) and copper(I) NHC-phenolamine complexes 6 and 7, respectively, that also retainthe phenol hydrogen atom. Attempts to selectively prepare2a-gave a copper(II) complex 9 that exhibits an (NO)2CuIIstructure with pendant imidazolium salt groups. Reaction be-tween the silver(I) bromide derivative of 1a and CuCl2·2H2Ogives a complex derived from a Cu6(O)(OH)4Cl3 core and two(NO) and one (CNO) ligands, respectively. The use of 2a and7 as precatalysts for 1,4-conjugate addition to enones andaziridination of alkenes was studied, showing that, whilstboth catalysts are active, enantioselectivities are low, whichis attributed to the lack of Cu-(NO) coordination. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009.
- Simonovic, Stevan,Whitwood, Adrian C.,Clegg, William,Harrington, Ross W.,Hursthouse, Michael B.,Male, Louise,Douthwaite, Richard E.
-
experimental part
p. 1786 - 1795
(2009/09/06)
-
- Nitrene transfer reactions catalysed by copper(I) complexes in ionic liquid using chloramine-T
-
The complex [Tpm*,BrCu(NCMe)]BF4 (Tpm *,Br = HC(3,5-Me2-4-Br-pyrazolyl)3) catalyses the aziridination of alkenes and the amidation of cyclic ethers with chloramine-T as the nitrene source and the ioni
- Cano, Israel,Nicasio, M. Carmen,Perez, Pedro J.
-
experimental part
p. 730 - 734
(2009/05/06)
-
- Desymmetrization of meso-N-acylaziridines with benzenethiols promoted by α,α-Diaryl-L-prolinols
-
α,α-Diaryl-L-prolinols were disclosed to promote the desymmetrization of meso-N-acylaziridines with benzenethiols to afford the products in good yields and moderate enantioselectivities (up to 61% ee), which can be greatly improved to >90% ee after a sing
- Lattanzi, Alessandra,Sala, Giorgio Della
-
supporting information; experimental part
p. 1845 - 1848
(2009/08/07)
-
- Facile construction of highly functionalized 2-pyrrolines via FeCl 3-catalyzed reaction of aziridines with arylalkynes
-
A series of highly functionalized 2-pyrrolines have been constructed by using a novel FeCl3-catalyzed reaction of aziridines with arylalkynes, in which an aryl-substituted alkenyl cation is involved.
- Fan, Jinmin,Gao, Linfeng,Wang, Zhiyong
-
supporting information; scheme or table
p. 5021 - 5023
(2010/01/06)
-
- Allylic Oxidations Catalyzed by Dirhodium Catalysts under Aqueous Conditions
-
The present invention relates to compositions and methods for achieving the efficient allylic oxidation of organic molecules, especially olefins and steroids, under aqueous conditions. The invention concerns the use of dirhodium (II,II) “paddlewheel complexes, and in particular, dirhodium carboximate and tert-butyl hydroperoxide as catalysts for the reaction. The use of aqueous conditions is particularly advantageous in the allylic oxidation of 7-keto steroids, which could not be effectively oxidized using anhydrous methods, and in extending allylic oxidation to enamides and enol ethers.
- -
-
Page/Page column 30
(2009/04/24)
-
- Silver(I)-catalyzed dual activation of propargylic alcohol and aziridine/azetidine: Triggering ring-opening and endo-selective ring-closing in a cascade
-
(Chemical Equation Presented) [Ag(COD)2]PF6 catalyzes the reaction between propargyl alcohols and N-tosylaziridines/azetidines leading to a diverse range of N,O-heterocycles, namely, oxazines, oxazepines, and oxazocines via ring-open
- Bera, Milan,Roy, Sujit
-
supporting information; experimental part
p. 8814 - 8817
(2010/03/01)
-
- Syntheses of acetonitrile ligated copper complexes with perfluoroalkoxy aluminate as counter anion and their catalytic application for olefin aziridination
-
Acetonitrile ligated copper complexes with perfluoroalkoxy aluminate Al {OC (CF3)3}4- as weakly coordinating counter anion are successfully synthesized. Aziridination of various olefins with PhINTs catalyzed by
- Li, Yang,Diebl, Bernd,Raith, Alexander,Kühn, Fritz E.
-
supporting information; body text
p. 5954 - 5956
(2009/04/11)
-
- Highly efficient alkene epoxidation and aziridination catalyzed by iron(II) salt + 4,4′,4″-trichloro-2,2′:6′,2″-terpyridine/ 4,4″-dichloro-4′-O-PEG-OCH3-2,2′:6′,2″- terpyridine
-
(Chemical Equation Presented) "Iron(II) salt + 4,4′,4″- trichloro-2,2′:6′,2″-terpyridine" is an effective catalyst for epoxidation and aziridination of alkenes and intramolecular amidation of sulfamate esters. The epoxidation of allylic-substituted cycloalkenes achieved excellent diastereoselectivities up to 90%. ESI-MS results supported the formation of iron-oxo and -imido intermediates. Derivitization of Cl3terpy to O-PEG-OCH3-Cl2terpy renders the terpyridine unit to be recyclable, and the "iron(II) salt + 4,4″-dichloro-4′-O-PEG-OCH3-2,2′:6′,2″- terpyridine" protocol can be reused without a significant loss of catalytic activity in the alkene epoxidation.
- Liu, Peng,Wong, Ella Lai-Ming,Yuen, Angella Wing-Hoi,Che, Chi-Ming
-
supporting information; experimental part
p. 3275 - 3278
(2009/05/27)
-
- Generation of nitrene by the photolysis of N-substituted iminodibenzothiophene
-
(Chemical Equation Presented) To evaluate the ability of dibenzothiophene N-substituted sulfilimines as photochemical nitrene sources, their photolyses in the presence of several trapping reagents, such as sulfides, olefins, and phosphorus compounds, were performed. In the reactions, the corresponding imino-transfer compounds, namely sulfilimines, aziridines, and iminophosphoranes, were formed in good yields, indicating dibenzothiophene N-tosyl and N-acylsulfilimines have a potent nature as nitrogen sources.
- Morita, Hiroyuki,Tatami, Atsushi,Maeda, Tetsuo,Byung, Ju Kim,Kawashima, Wataru,Yoshimura, Toshiaki,Abe, Hitoshi,Akasaka, Takeshi
-
scheme or table
p. 7159 - 7163
(2009/04/18)
-
- PhI(OAc)2/I2 induced aziridination of alkenes with TsNH2 under mild conditions
-
The aziridination of alkenes with the direct use of p-toluenesulfonamide (TsNH2) was achieved by using PhI(OAc)2 and I2 under mild conditions. The reaction affords aziridines in moderate to good yields, and offers good man
- Fan, Renhua,Pu, Dongming,Gan, Jianhong,Wang, Bing
-
p. 4925 - 4928
(2008/09/21)
-
- SPIROPIPERIDINE BETA-SECRETASE INHIBITORS FOR THE TREATMENT OF ALZHEIMER'S DISEASE
-
The present invention is directed to spiropiperidine compounds of formula (I) and tautomers thereof, which are inhibitors of the beta-secretase enzyme and that are useful in the treatment of diseases in which the beta-secretase enzyme is involved, such as
- -
-
Page/Page column 28-29
(2010/11/25)
-
- Tin(II) iodide-catalyzed selective aziridination or 1,2-diamination of alkenes with chloramine-T
-
-Tin(II) iodide selectively catalyzes reactions of alkenes in acetonitrile to afford the corresponding aziridines by the use of one equimolar amount of Chloramine-T [Ts(Cl)N] at room temperature and to afford the corresponding 1,2-diamines by the use of e
- Masuyama, Yoshiro,Ohtsuka, Masaru,Harima, Masaru,Kurusu, Yasuhiko
-
p. 503 - 506
(2007/10/03)
-
- Two-step synthesis of N-sulfonyl aziridines from epoxides
-
A convenient and high-yielding two-step synthesis of N-sulfonyl aziridines starting from epoxides is described. The method, which involves epoxide ring opening with sulfonamides and subsequent mesylation-cyclisation, is particularly suitable for variation
- Huang, Jianhui,O'Brien, Peter
-
p. 425 - 434
(2007/10/03)
-
- Practical aziridinations II: Electronic modifications to poly(pyrazolyl)borate-copper catalysts
-
A significant influence of the electronic features of poly(pyrazolyl)borate ligands on the efficiency of the copper-catalyzed aziridination reaction has been noted. Electron-deficient, bidentate di(pyrazolyl)borates in conjunction with copper(II) chloride
- Handy, Scott T.,Ivanow, Anatole,Czopp, Mark
-
p. 1821 - 1823
(2007/10/03)
-
- Novel aziridination of olefins: Direct synthesis from sulfonamides using t-BuOI
-
tert-Butyl hypoiodite (t-BuOI) was found to be a powerful reagent for synthesis of aziridines from olefins and sulfonamides. The aziridination of olefins was achieved by using sulfonamides with t-BuOI. Our preliminary findings represent the example of met
- Minakata, Satoshi,Morino, Yoshinobu,Oderaotoshi, Yoji,Komatsu, Mitsuo
-
p. 3337 - 3339
(2008/09/19)
-