1025-89-4Relevant academic research and scientific papers
Deconstructive Oxygenation of Unstrained Cycloalkanamines
Han, Bing,He, Yi-Heng,Pan, Jia-Hao,Wang, Yuan-Rui,Yu, Wei,Zhang, Jian-Wu
supporting information, p. 3900 - 3904 (2020/02/11)
A deconstructive oxygenation of unstrained primary cycloalkanamines has been developed for the first time using an auto-oxidative aromatization promoted C(sp3)?C(sp3) bond cleavage strategy. This metal-free method involves the substitution reaction of cycloalkanamines with hydrazonyl chlorides and subsequent auto-oxidative annulation to in situ generate pre-aromatics, followed by N-radical-promoted ring-opening and further oxygenation by 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) and m-cholorperoxybenzoic acid (mCPBA). Consequently, a series of 1,2,4-triazole-containing acyclic carbonyl compounds were efficiently produced. This protocol features a one-pot operation, mild reaction conditions, high regioselectivity and ring-opening efficiency, broad substrate scope, and is compatible with alkaloids, osamines, and peptides, as well as steroids.
New transformations of the reaction product of 4-(dichloromethylene)-2- phenyl-1,3-oxazol-5(4H)-one with triphenylphosphine
Brovarets,Golovenko,Sviripa,Zyuz',Chernega,Drach
, p. 1328 - 1334 (2007/10/03)
Consecutive treatment of the available 4-(dichloromethylene)-4-phenyl-1,3- oxazol-5(4H)-one with triphenylphosphine, water, and triethylamine gives a stabilized ylide Ph3P=CHCONHCOPh. Its structure was proved by X-ray diffraction. The ylide rea
Reactions of Nitrile Oxides and Nitrile Imines with Derivatives of 4,5-Dihydrooxazole and 4,5-Dihydrothiazole and with Related Compounds
Kennewell, Peter D.,Miller, David J.,Scrowston, Richard M.,Westwood, Robert
, p. 3563 - 3566 (2007/10/02)
2-Phenyl-4,5-dihydrooxazole 4 gives a cycloadduct 6 when treated with benzonitrile N-oxide; with a 1-oxoalkene- or α-oxoarene-nitrile N-oxide (RCOCNO), an open chain product, RCO2CH2N(CN)COPh , is obtained.The six-membered-ring analogue of compound 4 undergoes similar reactions.Depending on the nature of the ring substituents, a substituted 4,5-dihydrooxazole reacts with a C,N-diarylnitrile imine, to give either a cycloadduct, e.g. 17, or a 1,2,4-triazol-4-ium salt, e.g. 19.The product from the reaction of 4,5-dihydro-2-methylthiazole 1b with a nitrile imine depends upon the nature of the C- and N-substituents in the latter.In all cases it is postulated that a 4-substituted triazolium salt 24 is formed.This may lose thiirane to give a substituted 1,2,4-triazole 25, or it may react with a second molecule of the precursor of the nitrile imine, to give a 4-substituted 1,2,4-triazolium salt, e.g. 27, in which the precursor moiety is incorporated into the C-4 side chain.
Formation of 1,2,4-Triazoles by Cation Radical Induced Oxidative Addition of Arylhydrazones of Benzaldehyde and Butyraldehyde to Nitriles
Shine, Henry J.,Hoque, A. K. M. Mansurul
, p. 4349 - 4353 (2007/10/02)
1,3,5-Trisubstituted 1,2,4-triazoles have been made in excellent yields by oxidative cycloaddition of arylhydrazones of benzaldehyde and butyraldehyde to aceto-, propio-, and acrylonitrile.Oxidation was achieved with the cation radicals thianthrenyl perchlorate (Th(radical)+ClO4-) and tris(2,4-dibromophenyl)aminium hexachloroantimonate (Ar3N(radical)+SbCl6-).The triazoles thus had a phenyl, p-nitrophenyl, or 2,4-dinitrophenyl group in the 1-position, either a phenyl or propyl group in the 3-position, and a methyl, ethyl, or vinyl group in the 5-position.The formation of 5-vinyltriazoles was confirmed by their hydrogenation to 5-ethyltriazoles, which were obtained also by cycloadditions to propionitrile.New triazoles (eight) were also synthesized by a known alternative route, but in lower yields.The fact that 5-vinyltriazoles were formed instead of 5-cyano-2-pyrazolines shows that cation radical induced cycloadditions do not go through the nitrilimines.Cycloadditions with N-phenylbenzohydrazonoyl chloride and acrylonitrile in the presence of aluminum chloride and of triethylamine were carried out for comparison with the corresponding cation radical reaction.
SYNTHESIS AND THERMOLYSIS OF SOME N-HYDROXIMOYL- AND N-HYDRAZONOYLAZOLES
Plenkiewicz, Jan,Zdrojewski, Tadeusz
, p. 675 - 710 (2007/10/02)
The reactions of nitrile oxides or nitrile imines with pyrazole, imidazole, 1,2,3- and 1,2,4-triazole or tetrazole derivatives yield the appropriate N-hydroximoyl- or N-hydrazonoylazoles.Thermolysis of 1-hydroximoyltetrazoles, depending on the nature of the substituents in the tetrazole ring, yields 1,2,4-oxadiazoles or 5-amino-1,2,4-oxadiazoles upon hydrazoic acid or nitrogen evolution.Under similar conditions, 1-hydrazonoyltetrazoles give 1,2,4-triazoles or 5-amino-1,2,4-triazoles while 2-hydrazonoyltetrazoles decompose to the dihydro-1,2,4,5-tetrazine derivatives.
1,3-DIPOLAR CYCLOADDITIONS INDUCED BY CATION RADICALS. FORMATION OF 1,2,4-TRIAZOLES FROM OXIDATIVE ADDITION OF 1,4-DIPHENYLAZOMETHANE AND ARYL ALDEHYDE PHENYLHYDRAZONES TO NITRILES
Hoque, A. K. M. Mansurul,Kovelesky, Albert C.,Lee, Wang-Keun.,Shine, Henry J.
, p. 5655 - 5658 (2007/10/02)
Reaction of thianthrene cation radical perchlorate .(1+)*ClO4(1-)> with 1,4-diphenylazomethane (DPAM) in MeCN and EtCN led to the formation of 1,2,4-triazoles.Triazole formation is attributed to oxidative cycloaddition of benzaldehyde benzylhydrazone, the tautomer of DPAM, to the solvent nitriles.In confirmation, analogous cycloadditions were achieved by reaction of Th.(1+)*ClO4(1-) with some benzaldehyde phenylhydrazones in the same solvents.
