1025-89-4Relevant articles and documents
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.
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.
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.