Stereoselective Azepine-Ring Formation Through Ene Reactions of 3-(Alk-2-enyl)amino-2-cyanoacrolein Derivatives

Noguchi, Michihiko; Takamura, Shinji; Uchida, Tadashi; Hironaka, Mitsuko; Kakehi, Akikazu; Yamamoto, Hiroyuki

doi:10.1002/(sici)1099-0690(200004)2000:8<1489::aid-ejoc1489>3.0.co;2-z

Cited by 18 publications

(7 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…16 A general, effective, and simple synthesis of β-aminoenals based on the nucleophilic addition of secondary amines to 1,2,3-triazine (1) has been detailed. It complements the existing methods based on condensation with malondialdehyde or its equivalents (1,1,3,3-tetramethoxypropane), 19 hydroamination of propargylic aldehyde, 18 or dehydrogenative amination of acrolein. 20 It is likely that this general electrophilic character of 1,2,3-triazine and its ability to serve as a convenient equivalent of 2 may be extended to other classes of nucleophiles, and such studies are in progress.…”

mentioning

confidence: 99%

Direct Synthesis of β-Aminoenals through Reaction of 1,2,3-Triazine with Secondary Amines

et al. 2017

View full text Add to dashboard Cite

Simple and direct nucleophilic addition of secondary amines, including imidazole, to 1,2,3-triazine under mild reaction conditions (THF, 25–65 °C, 12–48 h), requiring no additives, cleanly provides β-aminoenals 4 in good yields (21 examples, 31–79%). The reaction proceeds by amine nucleophilic addition to C4 of the 1,2,3-triazine, in situ loss of N2, and subsequent imine hydrolysis to provide 4.

show abstract

mentioning

confidence: 99%

Direct Synthesis of β-Aminoenals through Reaction of 1,2,3-Triazine with Secondary Amines

et al. 2017

View full text Add to dashboard Cite

show abstract

“…The formation of iminoazepines 6 and 9 was explained by the formal imine-ene reaction of vinamidines 5 and 8 as discussed previously on the related 3-[N-(substituted)allylamino]-2-(substituted)acrolein derivatives: 7 thermal reaction of symmetric vinamidines 5 and 8 gave the less stable configurational isomers 5' and 8'. A 1,6-shift of the allylic hydrogen to the imine nitrogen in 5' and 8' gave conjugated azomethine ylide intermediates 10 and 11, which underwent 1,7-electrocyclization gave azepine derivatives 12 and 13.…”

mentioning

confidence: 65%

“…Nucleophilic attack of the amino nitrogen to the 7-position in 12 and 13 afforded the final products 6 and 9 (Scheme 3). It should be emphasized that vinamidines 5 and 8 which had a secondary allylamino moieties underwent an thermal imine-ene reaction through the isomeric 3-allylamino-2-(substituted)acrolein imines 5' and 8' and that NH-azomethine ylides 10 and 11 as well as the corresponding N-substituted ones 7 were postulated as key intermediates in azepine ring formation.…”

mentioning

confidence: 99%

Preparation of 2,5-iminoazepines via the imine–ene reaction of 3-allylamino-2-(substituted)acrolein imines

Takamura

Michinaka

Yamamoto

et al. 2000

Journal of Chemical Research

Self Cite

View full text Add to dashboard Cite

show abstract

“…It is known that 3-aminoacrolein and vinamidine derivatives can undergo amine exchange on addition of a primary amine. 7 Therefore, it may be possible that the intermediates 10 react intramolecularly or react further with acrolein derivative 1 and/or diamine 6, yet via amine exchange, to eventually produce a thermodynamically stable cyclic system, which is not the (1:1) cyclic product but the (2:2) cyclic product.…”

Section: Methodsmentioning

confidence: 99%

An Efficient Preparation of Macrocycles Bearing Vinamidine Moieties by the Cyclocondensation of Malonaldehyde Derivatives and 1,ω-Diaminoalkanes

et al. 2000

Self Cite

View full text Add to dashboard Cite

An efficient preparation of macrocycles 7 and 9 bearing vinamidine moieties is described. The key to the preparation is the (2:2) cyclocondensation of malonaldhyde derivatives 1 and 8 and 1,w-diaminoalkanes 6.Vinamidine (1,5-diazapentadiene) and vinamidinium salts are unique conjugate systems 1 because electron-donating and electron-withdrawing groups are separately attached to a carbon-carbon double bond. Vinamidinium salts have been used for the preparation of heterocycles, while vinamidine derivatives were rarely used for the synthetic purpose. 2 We have recently been studying an efficient preparation of N,N'-diaryl-3-cyanovinamidines 5a by the reaction of 3-butoxy-2-cyanoacrolein 1, a synthetic equivalent of cyanomalonaldehyde 2, with two molar equivalents of arylamine 3a via the initially formed product 4a. 3 Similar reaction of acrolein derivative 1 with aliphatic primary amines, such as benzyl-3b, cyclohexyl3c, and (R)-1-phenylethyl-amine 3d, also gave vinamidine derivatives 5b-d in good yields (Scheme 1). In our continuing study on the synthetic utility of malonaldehydes, we examined the reaction of acrolein derivative 1 and (methoxycarbonyl)malonaldehyde 8 4 with 1,w-diaminoalkanes 6 expecting to form cyclic products bearing vinamidine moieties. Scheme 1To a solution of 3-butoxy-2-cyanoacrolein 1, generated by the acid treatment of commercially available 1,3,3-tributoxy-2-cyanopropene, 5 in acetonitrile were added 1.2 equivalents of 1,6-diaminohexane (6e). The resultant mixture was refluxed for 8 hours and the solvent was evaporated to dryness, and the white solid was crystallized from methanol to give an unexpected (2:2) cyclic product 7e in 78% yield. The structure of 7e was confirmed on the basis of its analytical and spectroscopic data; in its IR spectrum characteristic absorption bands due to N-H and CN stretching were observed. The simple signal patterns in the 1 H and 13 C NMR spectra of product 7e implied that it has a symmetrical structure and, especially, its mass spectra showed the proposed molecular ion peaks [354 (M + ) for EI and 355 (MH + ) for CI]. Similar reaction of 1 with 1,2-diaminoethane (ethylenediamine) 6a, 1,4-diaminobutane 6c, 1,5-diaminopentane (gadaverine) 6d, and 1,12-diaminododecane 6f gave the corresponding (2:2) cyclic products 7a, 7c, 7d, and 7f in moderate to good yields (Scheme 2, Tables 1, 2). In addition, the reaction of 1 with 1,5-diaminopentane 6d gave another product 7d' along with product 7d. Product 7d' could not be isolated in its pure form; 7d' in deuteriochloroform and methanol was not stable and gradually converted to 7d within a few days on standing at room temperature. A prolonged reaction in refluxing acetonitrile (72 hours) gave only 7d (Table 1, run 4). The 1 H and 13 C NMR spectra of 7d' were almost consistent with those of 7d over the whole region. These findings suggest that product 7d' is a conformational isomer of 7d.(Methoxycarbonyl)malonaldehyde 8 was also reacted with diaminoalkanes 6a, 6c, 6e, and 6f; the same type of (2:2) cyclic products 9a, 9c...

show abstract

Stereoselective Azepine-Ring Formation Through Ene Reactions of 3-(Alk-2-enyl)amino-2-cyanoacrolein Derivatives

Cited by 18 publications

References 7 publications

Direct Synthesis of β-Aminoenals through Reaction of 1,2,3-Triazine with Secondary Amines

Direct Synthesis of β-Aminoenals through Reaction of 1,2,3-Triazine with Secondary Amines

Preparation of 2,5-iminoazepines via the imine–ene reaction of 3-allylamino-2-(substituted)acrolein imines

An Efficient Preparation of Macrocycles Bearing Vinamidine Moieties by the Cyclocondensation of Malonaldehyde Derivatives and 1,ω-Diaminoalkanes

Contact Info

Product

Resources

About