4749-28-4Relevant academic research and scientific papers
Organocatalytic Enantioselective Michael-Aldol[3+2] Annulation for the Synthesis of Nitro-Methanobenzo[7] annulenes
Liu, Jin-Yu,Zhang, Xiao-Hai,Zhang, Yang
supporting information, p. 5008 - 5011 (2021/09/28)
We report an enantioselective Michael-Aldol[3+2] annulation between 2-alkyl-3-hydroxynaphthalene-1,4-diones and nitroalkenes using a bifunctional thiourea catalyst, and a series of nitro-methanobenzo[7]annulenes with potential biological activities were synthesized in good yields with excellent enantio- and diastereoselectivities. A gram-scale synthesis and further transformation of the product demonstrated the synthetic value of this reaction.
Access to C5-Alkylated Indolines/Indoles via Michael-Type Friedel-Crafts Alkylation Using Aryl-Nitroolefins
Ertugrul, Berrak,Kilic, Haydar,Lafzi, Farrokh,Saracoglu, Nurullah
, p. 9018 - 9038 (2018/06/27)
A straightforward synthetic route toward C5-alkylated indolines/indoles has been developed. The strategy is composed of Zn(OTf)2-catalyzed Friedel-Crafts alkylation of N-benzylindolines with nitroolefins, and a series of diverse indolines was first obtained in up to 99% yield. This reaction provides a direct and practical route to a variety of the C5-alkylated indolines which were also utilized for accessing corresponding indoles. Indoline derivatives with free NH groups could be obtained through an N-deprotection reaction. Moreover, the primary alkyl nitro groups in both indolines and indoles are amenable to further synthetic elaborations, thereby broadening the diversity of the products.
Construction of multisubstituted tetrahydropyrans by a domino oxa-michael/tsujia-trost reaction
Wang, Liang,Menche, Dirk
, p. 10811 - 10823 (2013/02/22)
Biologically significant tetrahydropyrans (THP) were synthesized by a Tandem oxa-Michael/Tsujia-Trost reaction. Different Michael acceptors were investigated, and optimal results in terms of diastereoselectivities and yields were obtained with nitro olefins. The influence of the reaction parameters, substrate patterns, and type of metal counterions on the yield and stereochemical outcome of this process is discussed, and an explanation for the observed stereoselectivities is proposed.
Unexpected course of [2+3] cycloaddition of 2-nitropropene to (Z)-C,N-diphenylnitrone
Jasinski, Radomir,Mikulska, Maria,Baranski, Andrzej
body text, p. 41 - 45 (2012/04/23)
The [2+3] cycloaddition of 2-nitropropene to (Z)-C,N-diphenylnitrone leads to 3,4-trans-2,3-diphenyl-4-nitro-4-methyl- and 3,5-trans-2,3-diphenyl-5-nitro- 5-methylisoxazolidines as primary reaction products. This, however, is not the only pathway of 2-nitropropene conversion. In the reaction conditions, the nitroalkene also undergoes isomerisation and the resulting trans- and cis-1-nitropropenes yield respective stereoisomeric 2,3-diphenyl-4-nitro-5- methylisoxazolidines in the reaction with (Z)-C,N-diphenylnitrone.
Concise synthesis of tetrahydropyrans by a tandem oxa-michael/tsuji-trost reaction
Wang, Liang,Li, Pengfei,Menche, Dirk
supporting information; experimental part, p. 9270 - 9273 (2011/02/28)
A novel domino sequence facilitates the rapid assembly of polysubstituted tetrahydropyrans. The one-pot relay process generates up to three new stereogenic centers, including a tetrasubstituted carbon center, in a highly concise and convergent fashion from simple starting materials. Copyright
METHOD FOR ELIMINATING COLOR FORMING IMPURITIES FROM NITRO COMPOUNDS
-
Page/Page column 8, (2009/12/02)
A method for stabilizing nitro compounds against discoloration. The method comprises reacting nitro compounds containing color-forming impurities with nitric acid, neutralizing and washing the product, and distilling therefrom purified nitro compounds.
Novel synthesis of α-nitroalkenes from nitroalkanes via halogenation of intermediate N,N-bis(silyloxy)enamines
Kunetsky, Roman A.,Dilman, Alexander D.,Struchkova, Marina I.,Tartakovsky, Vladimir A.,Ioffe, Sema L.
, p. 5203 - 5205 (2007/10/03)
An approach to conjugated nitroalkenes via oxidation of N,N-bis(silyloxy)enamines with bromine or iodine in the presence of tetra-n-butylammonium acetate is described. The acetate ion plays a key role by acting as a mild desilylating reagent. This new strategy allows the synthesis of α-nitroalkenes from the corresponding nitroalkanes.
Propylene oxidation by palladium nitro and nitrato complexes: In situ NMR and IR studies
Beck, Irene E.,Golovin, Anatoli V.,Likholobov, Vladimir A.,Gusevskaya, Elena V.
, p. 2880 - 2887 (2007/10/03)
The mechanism of the propylene oxidation by Pd(NOn) Cl2-m(CH3CN)2 complexes (n=2,3; m=0,1,2) in chloroform solutions has been studied by 1 and IR spectroscopy. The main reaction products are acetone and 2-nitropropylene, with their ratio depending on the equilibrium existing in the reaction solutions between palladium complexes containing NOn ligands bonded to a palladium atom via either an oxygen or a nitrogen atom. Reactivities of the oxygen bonded nitrato and nitrito complexes are significantly higher than that of the nitrogen bonded nitro complex. Various new organopalladium intermediates have been observed and monitored in situ. A reversible insertion of the coordinated propylene into the Pd-O or Pd-N bonds results in nitrato-, nitrito- and nitropalladation intermediates, which then decompose via a β-hydrogen elimination. Two isomers of the nitritopalladation intermediate have been detected, i.e., a palladium metallacycle and an open ring complex, with the latter being much more reactive towards the β-hydrogen elimination than the former. The decomposition of the nitrato- and nitritopalladation intermediates results in the organometallic precursor of acetone, i.e., an acetonylpalladium complex, and then in acetone itself. On the other hand, the nitropalladation intermediate originates 2-nitropropylene. In the presence of dioxygen, which re-oxidizes the nitrosyl groups, the acetone formation becomes a catalytic reaction with respect to both palladium and nitrogen. Elsevier B.V. All rights reserved.
Kinetics and mechanisms of the gas-phase elimination of 2-substituted primary, secondary and tertiary hydroxy groups in nitroalkanes
Dominguez, Rosa Maria,Herize, Armando,Rotinov, Alexandra,Alvarez-Aular, Alvaro,Visbal, Gonzalo,Chuchani, Gabriel
, p. 399 - 408 (2007/10/03)
The kinetics of the gas-phase elimination of several 2-substituted primary, secondary and tertiary hydroxy groups in nitroalkanes were determined in a static reaction system over the temperature range 220-400°C and pressure range of 29-235 Torr. The reactions, in seasoned vessels, are homogeneous and unimolecular and obey a first-order rate law. The presence of secondary and tertiary hydroxy substituent at the 2-position of the nitro group in nitroalkanes leads to a retro-aldol type of decomposition. The mechanism may be rationalized in terms of a six-membered cyclic transition state to give the corresponding aldehyde or ketone and the nitroalkane, respectively. However, some of the primary 2-hydroxy groups in nitroalkanes undergo a dehydration process with very limited isomerization to the corresponding alkyl nitrate. The mechanism of dehydration is believed to proceed through a six-membered rather than the already reported four-membered cyclic transition state to give the nitroalkene and water. In the case of the primary hydroxy substituent in 2-methyl-2-nitro-1-pentanol, the products of elimination are HNO2 gas and 3-hydroxy-2-methyl-1-propene. This reaction is rationalized in terms of a four-membered cyclic transition state type of mechanism. The kinetic and thermodynamic parameters of the hydroxynitroalkane substrates are presented and discussed. Copyright 2004 John Wiley & Sons, Ltd.
CYCLOADDITION DES METHYLAZIDE ET PHENYLAZIDE AU β-NITROSTYRENE ET AU NITROPROPENE HOMOLOGUE
Cailleux, P.,Piet, J. C.,Benhaoua, H.,Carrie, R.
, p. 45 - 52 (2007/10/03)
Phenylazide and methylazide reacts with title olefines and gives two isomeric triazoles without nitro group, and 4-nitro-1,2,3 triazole.The isomerisation of starting alkenes explains the formation of isomeric triazoles.Oxydation of amino-nitro-diazocompounds in equilibrium with 1,2,3 triazolines leads to 4-nitro-1,2,3 triazoles.
