1173191-63-3Relevant academic research and scientific papers
Synthesis of bicyclic N,N-enaminals by cyclization of alk-4-ynals with aliphatic diamines in DMSO upon treatment with KOH
Gvozdev,Shavrin,Nefedov
, p. 2430 - 2437 (2014/11/08)
A cyclization of alk-4-ynals with aliphatic diamines in DMSO upon treatment with KOH was found to lead to bicyclic N,N-enaminals. The studies of this reaction showed that 1,3-diaminopropane and N-methyl-1,3-diaminopropane gave (E)-6-(arylmethylidene)octahydropyrrolo[1,2-a]pyrimidines in 45 - 78% yields, whereas 1,2-diaminoethane gave 5-(arylmethylidene)hexahydropyrrolo[1,2-a] imidazoles as mixtures of E- and Z-isomers in up to 75% total yield. The mechanism of these new cascade cyclization reactions includes formation of the equilibrium mixtures of imines and cyclic aminals with subsequent intramolecular hydroamination of the triple bond having considerable ionic character.
Synthesis of 6-(arylmethylidene)octahydropyrrolo[1,2-a]pyrimidines and 5-(arylmethylidene)hexahydropyrrolo[1,2-a]imidazoles by the interaction of alk-4-ynals with a,?-diaminoalkanes in DMSO in the presence of KOH
Shavrin, Konstantin N.,Gvozdev, Valentin D.,Nefedov, Oleg M.
, p. 140 - 141 (2013/07/26)
Cyclization of alk-4-ynals with a,?-diaminoalkanes in DMSO under the action of KOH affords bicyclic N,N-enaminals - 6-(aryl- methylidene)octahydro[1,2-a] pyrimidines and 5-(arylmethylidene)hexahydro[1,2-a]imidazoles.
Synthesis of 5-methylidenehexahydropyrrolo[l,2-a]imidazoles and 6-methylideneoctahydropyrrolo[l,2-a]pyrimidines by the reaction of 1-alkynyl-1-chlorocyclopropanes with lithium derivatives of 1,2- and 1,3-diaminoalkanes
Shavrin,Gvozdev,Nefedov
experimental part, p. 1451 - 1458 (2011/04/16)
A reaction of 1-alkynyl-1-chlorocyclopropanes with excess of lithium derivative of 1,2-diaminoethane leads to 5-methylidenehexahydropyrrolo[l,2-a] imidazoles in 35-72% yields, whereas analogous reaction with lithium derivative of 1,3-diaminopropane gives 6-methyl-ideneoctahydropyrrolo[l,2-a]pyrimidine in up to 50% yield. A mechanism of these unusual multi-step processes includes dehydrochlorination of 1-alkynyl-1-chlorocyclopropanes to form conjugated alkynylcyclopropenes capable of addition of monoalkylamide ions at the double bond, leading to the corresponding secondary cyclopropylamines; the latter under the reaction conditions isomerize to the linear imines, which further undergo a cascade cyclization with sequential involvement of the C=N and C≡C bonds.
5-Methylenehexahydropyrrolo[1,2-a]imidazoles and 6-methyleneoctahydropyrrolo[1,2-a]pyrimidines in the reactions of 1-(alk-1-ynyl)-1-chlorocyclopropanes with lithium derivatives of 1,2- and 1,3-diaminoalkanes
Shavrin, Konstantin N.,Gvozdev, Valentin D.,Nefedov, Oleg M.
experimental part, p. 300 - 301 (2009/05/27)
Unusual reactions of 1-(alk-1-ynyl)-1-chlorocyclopropanes with lithium derivatives of 1,2-diaminoethane, 1,3-diaminopropane and 1-methylamino-3-aminopropane in THF at 20 °C give previously unknown 5-methylenehexahydropyrrolo[1,2-a]imidazoles and 6-methyleneoctahydropyrrolo[1,2-a]pyrimidines with up to 60% yields.
