- Interaction of Nitric Oxide with Paramagnetic and Diamagnetic Alkyls of Titanium, Zirconium, Vanadium, Niobium, and Tantalum
-
An earlier observation that there is a profound difference in the way paramagnetic and diamagnetic alkyl compounds of transition metals react with nitric oxide is extended.The reaction of NO with bis(η5-cyclopentadienyl)-dimethylniobium(IV), d1, can be followed by nuclear magnetic resonance spectra and intermediates detected.The final product of the reaction is bis(η5-cyclopentadienyl)methyloxoniobium(V), which with excess of NO, gives the N-methyl-N-nitrosohydroxylaminato-complex Nb(η-C5H5)2(O).An intermediate niobioaziridine collapses with methylnitrene transfer to give azomethane, and in the presence of styrene, an aziridine.Tetrakis(trimethylsilylmethyl)vanadium(IV) gives with NO the previously known VO(CH2SiMe3)3 while the titanium(III), d1, compounds Ti(η-C5H5)2R (R = Ph or CH2Ph) lose both cyclopentadienyl and aryl or benzyl groups to give trimeric species Ti3(η-C5H5)3O4(NO) that has oxo-bridges and a bent Ti-NO group.The diamagnetic alkyls of titanium and zirconium, TiR4, TiR3Cl, TiR2Cl2, ZrR4, and ZrR2Cl2 (R = CH2SiMe3 or CH2CMe3) and NO give N-alkyl-N-nitrosohydroxylaminato-complexes.The titanium compounds are six-co-ordinate with unidentate and bidentate ON(R)NO groups, while the zirconium compounds are eight-co-ordinate with chelate groups only.The pentamethyls MMe5 (M = Nb or Ta) and NO give NbMe23 and 2>2 respectively.
- Middleton, A. Robert,Wilkinson, Geoffrey
-
-
Read Online
- Diethylammonium iodide as catalyst for the metal-free synthesis of 5-aryl-2-oxazolidinones from aziridines and carbon dioxide
-
The catalytic potential of ammonium halide salts was explored in the coupling reaction of a model aziridine with carbon dioxide, highlighting the superior activity of [NH2Et2]I. Then, working at room temperature, atmospheric CO2 pressure and in the absenc
- Bresciani, Giulio,Bortoluzzi, Marco,Pampaloni, Guido,Marchetti, Fabio
-
p. 4152 - 4161
(2021/05/19)
-
- A facile and regioselective multicomponent synthesis of chiral aryl-1,2-mercaptoamines in water followed by monoamine oxidase (MAO-N) enzymatic resolution
-
A facile microwave assisted three-component protocol allows the synthesis of chiral aryl-1,2-mercaptoamines in water in a few minutes with high yields, bypassing the use of toxic aziridine intermediates. The chiral 1,2-mercaptoamines were then deracemized through enzymatic resolution of the racemates using monoamine oxidase (MAO-N) biocatalysts.
- Lauder, Kate,Masci, Domiziana,Toscani, Anita,Al Mekdad, Aya,Black, Gary W.,Brown, Nicola L.,Turner, Nicholas J.,Luisi, Renzo,Castagnolo, Daniele
-
p. 8982 - 8986
(2019/10/28)
-
- Styrene Aziridination by Iron(IV) Nitrides
-
Thermolysis of the iron(IV) nitride complex [PhB(tBuIm)3FeN] with styrene leads to formation of the high-spin iron(II) aziridino complex [PhB(tBuIm)3Fe-N(CH2CHPh)]. Similar aziridination occurs with both electron-rich and electron-poor styrenes, while bulky styrenes hinder the reaction. The aziridino complex [PhB(tBuIm)3Fe-N(CH2CHPh)] acts as a nitride synthon, reacting with electron-poor styrenes to generate their corresponding aziridino complexes, that is, aziridine cross-metathesis. Reaction of [PhB(tBuIm)3Fe-N(CH2CHPh)] with Me3SiCl releases the N-functionalized aziridine Me3SiN(CH2CHPh) while simultaneously generating [PhB(tBuIm)3FeCl]. This closes a synthetic cycle for styrene azirdination by a nitride complex. While the less hindered iron(IV) nitride complex [PhB(MesIm)3FeN] reacts with styrenes below room temperature, only bulky styrenes lead to tractable aziridino products.
- Mu?oz, Salvador B.,Lee, Wei-Tsung,Dickie, Diane A.,Scepaniak, Jeremiah J.,Subedi, Deepak,Pink, Maren,Johnson, Michael D.,Smith, Jeremy M.
-
p. 10600 - 10603
(2015/09/02)
-
- Proline-catalyzed synthesis of 5-aryl-2-oxazolidinones from carbon dioxide and aziridines under solvent-free conditions
-
Natural a-amino acids were proven to be ecofriendly and recyclable catalysts for the carboxylation of aziridines with CO2 without utilization of any organic solvents or additives. Notably, a series of 5-aryl-2-oxazolidinones were obtained in go
- Dou, Xiao-Yong,He, Liang-Nian,Yang, Zhen-Zhen
-
-
- Regioselective synthesis of 5-aryl-2-oxazolidinones from carbon dioxide and aziridines using Br- Ph3+PPEG 600P+Ph3Br- as an efficient, homogenous recyclable catalyst at ambient conditions
-
Polyethylene glycol functionalized phosphonium salt (Br- Ph 3+PPEG600P+Ph3Br -) was found to be an efficient, homogenous, recyclable catalyst for coupling of CO2 with a variety of aziridines producing corresponding 5-aryl-2-oxazolidinones with good yields and excellent regioselectivity under relatively mild and solvent free conditions. Furthermore, the catalyst was effectively recycled for four consecutive cycles without any significant loss in its catalytic activity and selectivity.
- Watile, Rahul A.,Bagal, Dattatraya B.,Patil, Yogesh P.,Bhanage, Bhalchandra M.
-
p. 6383 - 6387
(2011/12/22)
-
- METHOD FOR SYNTHESIZING AN N-UNSUBSTITUTED OR N-SUBSTITUTED AZIRIDINE
-
Process for preparing an N-unsubstituted or N-substituted aziridine of the formula which comprises reacting an olefin of the formula I where R1 to R5 are each, independently of one another, hydrogen, a linear or branched alkyl radica
- -
-
Page/Page column 6
(2010/08/07)
-
- Catalyst-free process for the synthesis of 5-aryl-2-oxazolidinones via cycloaddition reaction of aziridines and carbon dioxide
-
A simple approach for facile synthesis of 5-aryl-2-oxazolidinones in excellent regioselectivity from aziridines under compressed CO2 conditions was developed in the absence of any catalyst and organic solvent. The reaction outcome was found to be tuned by subtly adjusting CO2 pressure. The adduct formed in situ of aziridine and CO2 is assumed to act as a catalyst in this reaction, which was also studied by means of in situ FT-IR technique.
- Dou, Xiao-Yong,He, Liang-Nian,Yang, Zhen-Zhen,Wang, Jing-Lun
-
supporting information; experimental part
p. 2159 - 2163
(2010/10/21)
-
- Polystyrene-supported amino acids as efficient catalyst for chemical fixation of carbon dioxide
-
Four new polystyrene-supported amino acids have been synthesized and applied to the chemical fixation of carbon dioxide for the first time. Two series of experiments with polystyrene-supported threonine (PS-Thr) and polystyrene-supported tyrosine (PS-Tyr) as catalyst, respectively, were conducted to study the effect of the reaction conditions on the carboxylation of propylene oxide/carbon dioxide. There was no considerable decrease in the yield of propylene carbonate after the polystyrene-supported amino acids were used five times, indicating that these catalysts are very stable. It was demonstrated that these catalysts were very efficient in the carboxylation of various epoxides and aziridines with carbon dioxide under mild conditions without any solvents. The mechanism for this carboxylation is also discussed.
- Qi, Chaorong,Ye, Jinwu,Zeng, Wei,Jiang, Huanfeng
-
supporting information; experimental part
p. 1925 - 1933
(2010/11/04)
-
- Lewis basic ionic liquids-catalyzed synthesis of 5-aryl-2-oxazolidinones from aziridines and CO2 under solvent-free conditions
-
A series of easily prepared Lewis basic ionic liquids were developed as recyclable and efficient catalysts for selective synthesis of 5-aryl-2-oxazolidinones from aziridines and CO2 without utilization of any organic solvent or additive. Notably, high conversion, chemo- and regio-selectivity were attained when 1-butyl-4-aza-1-azaniabicyclo[2.2.2]octane bromide ([C4DABCO]Br) was used as the catalyst. Furthermore, the catalyst could be recycled over four times without appreciable loss of catalytic activity. The effects of the catalyst structure and various reaction parameters on the catalytic performance were investigated in detail. This protocol was found to be applicable to a variety of aziridines producing the corresponding 5-aryl-2-oxazolidinones in good yields and excellent regioselectivities. Therefore, this solvent-free process thus represents an environmentally friendly process for ionic liquid-catalyzed conversion of CO2 into value-added chemicals. A possible catalytic cycle for CO2 activation induced by nucleophilic tertiary nitrogen of the ionic liquid was proposed, based on studies using in situ FT-IR spectroscopy under CO2 pressure.
- Yang, Zhen-Zhen,He, Liang-Nian,Peng, Shi-Yong,Liu, An-Hua
-
supporting information; experimental part
p. 1850 - 1854
(2011/02/23)
-
- Quaternary ammonium bromide functionalized polyethylene glycol: A highly efficient and recyclable catalyst for selective synthesis of 5-aryl-2-oxazolidinones from carbon dioxide and aziridines under solvent-free conditions
-
(Chemical Equation Presented) A quaternary ammonium bromide covalently bound to polyethylene glycol (PEG, MW = 6000), i.e., PEG6000- (NBu3Br)2, was found to be an efficient and recyclable catalyst for the cycloaddition reaction of aziridines to CO2 under mild conditions without utilization of additional organic solvents or cocatalysts. As a result, 5-aryl-2-oxazolidinone was obtained in high yield with excellent regioselectivity. The catalyst worked well for a wide variety of 1-alkyl-2-arylaziridines. Besides, the catalyst could be recovered by centrifugation and reused without significant loss of catalytic activity and selectivity.
- Du, Ya,Wu, Ying,Liu, An-Hua,He, Liang-Nian
-
p. 4709 - 4712
(2008/09/21)
-
- Directed ortho lithiation of N-alkylphenylaziridines
-
(Chemical Equation Presented) The ortho lithiation-trapping sequence of phenylaziridines is described. This methodology, which counts on the ability of the aziridino group to act as a directed metalation group (DMG), provides an easy access to functionali
- Capriati, Vito,Florio, Saverio,Luisi, Renzo,Musio, Biagia
-
p. 3749 - 3752
(2007/10/03)
-
- Formation of azomethine ylids by thermolysis of oxazolidines. Study of the reaction in solution and in the gaseous phase
-
Thermolysis of oxazolidines leads to azomethine ylids via cycloreversion.In the liquid phase, these intermediates then give 1-3 dipolar cycloaddition; in the gaseous phase, they lead to aziridines.With an alkyl group in position 2, we observed also the formation of enamines.The effect of substituents on both the cycloreversion reaction and the evolution of azomethine ylids was studied.The mechanism of the process tautomerism aziridine -> azomethine ylid -> enamine is discussed.Keywords - azomethine ylids / oxazolidines / cycloreversion / aziridines / enamines / tautomerism
- Bureau, R.,Mortier, J.,Joucla, M.
-
p. 584 - 596
(2007/10/02)
-
- FLASH VACUUM THERMOLYSIS OF OXAZOLIDINES : A NEW WAY TO REACTIVE AZOMETHINE YLIDES. RING CLOSURE TO AZIRIDINES.
-
Flash vacuum thermolysis of oxazolidines leads to azomethine ylides which undergo ring closure to aziridines.
- Joucla, Marc,Mortier, Jacques,Bureau, Ronan
-
p. 2975 - 2976
(2007/10/02)
-
- Interproton Coupling Constant Variations in 3-Membered Ring Heterocycles. Separation of Lone Pair and Inductive Effects
-
In order to separate inductive and lone pair effects on geminal vicinal coupling constants in a stereochemically well-defined system, the 1H NMR spectra of phenylcyclopropane (1), N-methyl-2-phenylaziridine (2), styrene oxide (3) and 1,1-dimethyl-2-phenyl
- Crist, DeLanson R.,Borsetti, Arnold P.,Jordan, Guy J.,Hammer, Charles F.
-
-
- Dimethyl-α-styrylsulphonium Bromide as a Reaction Intermediate
-
The addition product of styrene, bromine, and dimethyl sulphide was treated with bases to give the dimethyl-α-styrylsulphonium ion which reacted rapidly with various nucleophiles and also underwent slower base-catalysed rearrangement.
- Chow, Yuan L.,Bakker, Bert H.,Iwai, Kiyoshi
-
p. 521 - 522
(2007/10/02)
-
- S-Ethenylsulfoximine Derivatives. Reagents for Ethylenation of Protic Nucleophiles
-
The preparation of S-vinyl and S-(2-substituted)ethenyl derivatives of sulfoximines is described.Vinyl-, (2-phenylethenyl)-, (2,2-diphenylethenyl)-, (2-methyl-1-propenyl)-, (dimethylamino)phenyloxosulfonium fluoroborates were found to undergo an addition-elimination reaction sequence with protic nitrogen and carbon nucleophiles, resulting in ethylenation of the nucleophile and N,N-dimethylbenzenesulfinamide.Primary amines gave aziridines, enamines gave cyclopropyl derivatives of iminium salts or pyrrolidinium salts, anions of active methylene compounds gave dihydrofurans and/or cyclopropanes, and anions of nitroalkanes gave cyclic nitronic esters and/or nitrocyclopropanes.In several cases vinyl salts were generated in situ from β-methoxyoxosulfonium salts.Treatment of (-)-(S)-dimethylamino)phenyl(trans-2-phenylethenyl)oxosulfonium fluoroborate with methyl cyanoacetate in methanol containing sodium methoxide gave, in 81percent yield, (+)-(1S,2R)-methyl 1-cyano-2-phenylcyclopropanecarboxylate of 25.5percent optical purity.The same salt upon treatment with methyl nitroacetate gave, in 95percent yield, methyl 4-phenyl-3-isoxazolinecarboxylate 2-oxide with 33percent enantiomeric excess.Cyclopropanes were formed upon treatment of S-methyl-S-(trans-2-phenylethenyl)-N-(p-tolylsulfonyl)sulfoximine with anions of active methylene compounds.
- Johnson, Carl R.,Lockard, James P.,Kennedy, Eugene R.
-
p. 264 - 271
(2007/10/02)
-