Diacetylene and its derivatives in heterocyclization reactions

Maretina, I. A.; Трофимов, Б. А.

doi:10.1016/s0065-2725(02)82028-1

Cited by 13 publications

(36 citation statements)

References 107 publications

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“…C 6 H 6 , 1.5 h) [17,22]. Presumably, intermediate 10 undergoes [3,3]-sigmatropic rearrangement to methoxydihydropyranone 11 which loses methanol molecule to afford compound 8 (Scheme 2).…”

Section: Reactions At the Methyl Groupmentioning

confidence: 99%

“…Adduct 12 was formed by reaction of 4a with diethyl oxalate via condensation at the methyl group in 4 [17,22]. Aldol condensation of 12 with formaldehyde gave hydroxymethyl derivative 13, and cyclization of the latter in acid medium afforded furandione 14 and then furopyranone 15.…”

Section: Reactions At the Methyl Groupmentioning

confidence: 99%

“…Aldol condensation of 12 with formaldehyde gave hydroxymethyl derivative 13, and cyclization of the latter in acid medium afforded furandione 14 and then furopyranone 15. Reactions of 15 with amines and thiols are accompanied by opening of the pyranone ring with formation of dihydrofuranone derivatives 16 [22] (Scheme 3).…”

Section: Reactions At the Methyl Groupmentioning

confidence: 99%

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4,4-Dialkoxybutan-2-ones as Synthons

Maretina

2005

Russ J Org Chem

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“…C 6 H 6 , 1.5 h) [17,22]. Presumably, intermediate 10 undergoes [3,3]-sigmatropic rearrangement to methoxydihydropyranone 11 which loses methanol molecule to afford compound 8 (Scheme 2).…”

Section: Reactions At the Methyl Groupmentioning

confidence: 99%

Section: Reactions At the Methyl Groupmentioning

confidence: 99%

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4,4-Dialkoxybutan-2-ones as Synthons

Maretina

2005

Russ J Org Chem

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We report here on the study of nucleophilic addition of 1,2-aminothiols to diacetylene in liquid ammonia or in methanol aimed at elucidation of the reaction direction and at preparation of new biologically active compounds.

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mentioning

confidence: 99%

“…Diacetylene opens up new fields for preparation versatile unsaturated heteroatomic compounds with specific characteristics [1,2]. Reactions of diacetylene with thiols and hydrogen sulfide in various media [3], in particular, in liquid ammonia [4], gave rise to enyne sulfides [5] and thiophene [6].…”

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confidence: 99%

Reactions of aliphatic, aromatic, and heterocyclic aminothiols with diacetylene

Volkov

Volkova

2004

Russ J Org Chem

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Reactions of aliphatic, aromatic, and heterocyclic aminothiols with diacetylene in liquid ammonia or methanol furnished the corresponding aminoorganylsulfanylbutenynes of predominantly Z-configuration.Diacetylene opens up new fields for preparation versatile unsaturated heteroatomic compounds with specific characteristics [1,2]. Reactions of diacetylene with thiols and hydrogen sulfide in various media [3], in particular, in liquid ammonia [4], gave rise to enyne sulfides [5] and thiophene [6].We report here on the study of nucleophilic addition of 1,2-aminothiols to diacetylene in liquid ammonia or in methanol aimed at elucidation of the reaction direction and at preparation of new biologically active compounds. The combination in a single molecule of acid and base properties makes it possible for the compound to exist in a form of an internal salt (zwitter-ion). By changing the pH of the medium the ammonium salt HSCH 2 CH 2 + NH 3 can be converted through SCH 2 CH 2 + NH 3 into a free base SCH 2 CH 2 NH 2 [7].The nucleophilic ability of 1,2-aminothiols in reactions with activated unsaturated compounds is well consistent with the acidity of the mercapto and amino groups in aminothiols [7]. According to [8] at comparable values of the medium pK and comparable spatial surrounding the HS anions are 280 times more active than NH 2 anions. Therefore the proton elimination from the b-aminoethanethiol occurred exclusively from the SH groups. The analysis of published data [912] revealed that sometimes NH 2 groups are involved, and cyclization also may happen. For instance, the reaction of a-acetylene ketones with b-aminoethanethiol hydrochloride in methanol solution in the presence of sodium methylate resulted in bis(acylvinylaminoethyl) disulfides, i.e., only amino group was involved into the process. At excess initial ketone (2:1) alongside the disulfides formed also 1,4-bis-(acylvinyl)-1-thia-4-azabutanes [9].Taking into account the presence of two reaction sites in aminothiol molecules and the thiols ability to be oxidized into disulfides it was presumable that the reaction would give rise to several products. However the use of mild conditions (liquid ammonia) prevented participation in the reaction of the amino group and also disulfides formation. The basic quality of ammonia favors thiolate ion formation, and the high reactivity of the latter is ensured by its weak solvation with the ammonia molecules. Therefore the reaction begins by a nucleophilic attack of the thiolate ion on the triple bond and affords the corresponding enyne sulfides IV that were isolated in high yields (7898%).The diacetylene reaction with the b-aminoethanethiol in methanol in the presence of alkali also resulted in sulfide I but in a lower yield (52%).

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