Triene electrocyclizations

Marvell, Elliot N.; Caple, G.; DELPHEY, C.; Platt, Jamie L.; Polston, Norman L.; Tashiro, John Toshiyuki

doi:10.1016/0040-4020(73)80197-8

Cited by 31 publications

(11 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The thermal cyclization of 1-azatrienes to 1,2-dihydropyridines, known as 6p-azaelectrocyclization, 8,9 is analogous to the well-known ring closure of 1,3,5-hexatrienes to 1,3-cyclohexadienes. [10][11][12] This process likely involves a classical concerted electrocyclization, which proceeds in a disrotatory mode.…”

Section: Renaissance Of 6p-azaelectrocyclization: Remarkable Acceleration By Substituent Effectsmentioning

confidence: 99%

“…rapid 6p-azaelectrocyclization ported, 9 the reactivity study as well as applicability to natural products synthesis are very limited in the literature probably because the cyclization process requires high temperature and the preparation methods for 3-cis-1-azatrienes, precursors of the electrocyclization, are not well established. 8,15 Recently, Okamura and co-workers have reported that Schiff base 10, which was obtained from 13-tert-butyl-13cis-retinal and n-butylamine, produced 1,2-dihydropyridine at a relatively fast rate, namely at 23 °C with a half-life of 11 min [Scheme 4(c)].…”

Section: Renaissance Of 6p-azaelectrocyclization: Remarkable Acceleration By Substituent Effectsmentioning

confidence: 99%

See 1 more Smart Citation

Exploring a Unique Reactivity of 6π-Azaelectrocyclization to Enzyme Inhibition, Natural Products Synthesis, and Molecular Imaging: An Approach to Chemical Biology by Synthetic Chemists

Tanaka¹,

Fukase²,

Katsumura³

2011

Synlett

View full text Add to dashboard Cite

While elucidating the inhibitory mechanism of a hydrolytic enzyme by aldehyde-containing natural products, we discovered a reaction involving a rapid 6p-azaelectrocyclization of azatrienes generated from aldehyde with lysine residues. The electrocyclic reaction of the 1-azatriene system, a cyclization precursor, exhibited a substituent effect. Structure-reactivity studies showed that azaelectrocyclization, which usually proceeds in low yield at high temperatures, produced a quantitative yield in less than 5 minutes at room temperature. Asymmetric chiral piperidine synthesis and a one-pot library synthesis of pyridines on solid supports were applied to synthesize pyridine/indole alkaloid-type natural products. Additionally, we developed lysine-based labeling and engineering of biomolecules and living cells based on the rapid 6pazaelectrocyclization.Both 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) as a metal chelating agent and fluorescent groups, as well as oligosaccharide structures were introduced efficiently and selectively into surface lysines within 10 minutes at concentrations as low as 10 -8 M. The DOTA-labeled somatostatin and glycoproteins were then radiometallated with 68 Ga; the receptor-mediated accumulation of somatostatin in pancreas and the oligosaccharide-dependent circulatory residence of glycoproteins were visualized by microPET for the first time. Furthermore, we succeeded to image the trafficking of the fluorescence-labeled lymphocytes noninvasively, while the N-glycan-engineered lymphocytes targeted the colon carcinoma in tumor mouse model; the tumor-targeting cells were thus synthesized using our 6p-azaelectrocyclization. 7Site-Selective and Non-Destructive Protein Labeling via Azaelectrocyclization-Induced Cascade Reactions 8 Conclusion

show abstract

Section: Renaissance Of 6p-azaelectrocyclization: Remarkable Acceleration By Substituent Effectsmentioning

confidence: 99%

Section: Renaissance Of 6p-azaelectrocyclization: Remarkable Acceleration By Substituent Effectsmentioning

confidence: 99%

Exploring a Unique Reactivity of 6π-Azaelectrocyclization to Enzyme Inhibition, Natural Products Synthesis, and Molecular Imaging: An Approach to Chemical Biology by Synthetic Chemists

Tanaka¹,

Fukase²,

Katsumura³

2011

Synlett

View full text Add to dashboard Cite

show abstract

“…The thermal cyclization of 1‐azatrienes to 1,2‐dihydropyridines, known as 6π‐azaelectrocyclization,9 is analogous to the well‐known ring closure of 1,3,5‐hexatrienes to 1,3‐cyclohexadienes 10–12. This process likely involves a classical concerted electrocyclization, which proceeds in a disrotatory mode.…”

Section: Renaissance Of 6π‐azaelectrocyclization: Remarkable Acceleramentioning

confidence: 99%

New strategy in synthetic biology: from enzyme inhibition and natural products synthesis to PET imaging by 6π‐azaelectrocyclization

Tanaka

Fukase

Katsumura

2010

The Chemical Record

View full text Add to dashboard Cite

While elucidating the inhibitory mechanism of a hydrolytic enzyme by aldehyde-containing natural products, we discovered a reaction involving a rapid 6pi-azaelectrocyclization of azatrienes generated from aldehyde with lysine residues. The electrocyclic reaction of the 1-azatriene system, a cyclization precursor, exhibited a substituent effect. Structure-reactivity studies showed that azaelectrocyclization, which usually proceeds in low yield at high temperatures, produced a quantitative yield in less than 5 min at room temperature. Asymmetric chiral piperidine synthesis and a one-pot library synthesis of pyridines on solid-supports were applied to synthesize pyridine/indole alkaloid-type natural products. Additionally, we developed lysine-based labeling of biomolecules based on the rapid 6pi-azaelectrocyclization. Both DOTA as a metal chelating agent (either for MRI, PET, or other radiopharmaceutical purposes, e.g., SPECT with gamma emitters) as well as fluorescent groups were introduced efficiently and selectively into lysine residues within 10 min at concentrations as low as 10(-8) m. The DOTA-labeled somatostatin and glycoproteins were then radiometallated with (68)Ga to observe the receptor-mediated accumulation of somatostatin in pancreatic tissue. Furthermore, microPET visualized the oligosaccharide dependent circulatory residence of glycoproteins for the first time.

show abstract

“…12 Marvel and coworkers reported that ester groups on C2 and C5 facilitated the cyclization. 13 Three 'push-pull' disubstitution patterns were demonstrated as a significant accelerating factor by Fu, Liu, and co-workers through a number of computational studies. 14 In our cases, 1,3,5-trienes 4 and 5 possess a complex substitution feature: two carbonyls on C1, a methoxy or hydroxy on C2, a methoxy on C4, and a phenyl on C6.…”

Section: Special Topic Syn Thesismentioning

confidence: 97%

Synthetic Studies toward Bi-linderone Lead To Unexpected 6π-Electrocyclization Reactions: A Facile Construction of Highly Congested Spiro Compounds

Xiao

Zhang

2015

Synthesis

View full text Add to dashboard Cite

During synthetic studies toward bi-linderone, unexpected 6π-electrocyclizations of 4,5-dimethoxy-2-[(E)-1,3-dimethoxy-5-phenylpenta-2,4-dienylidene]cyclopent-4-ene-1,3-dione and 2-[(E)-1-hydroxy-3-methoxy-5-phenylpenta-2,4-dienylidene]-4,5-dimethoxycyclopent-4-ene-1,3-dione were observed. The cyclization of 4,5-dimethoxy-2-[(E)-1,3-dimethoxy-5-phenylpenta-2,4-dienylidene]cyclopent-4-ene-1,3-dione gave a rare example of a 6π-electrocyclization reaction that occurs readily at room temperature in the presence of silica gel. Meanwhile, the intramolecular hydrogen bonding existing in 2-[(E)-1-hydroxy-3-methoxy-5-phenylpenta-2,4-dienylidene]-4,5-dimethoxycyclopent-4-ene-1,3-dione afforded a strong contribution to the stability of the flat conformation, and this hampered the 6π-electrocyclization process. These 6π-electrocyclizations afforded a facile approach to highly congested spiro compounds.

show abstract

Triene electrocyclizations

Cited by 31 publications

References 28 publications

Exploring a Unique Reactivity of 6π-Azaelectrocyclization to Enzyme Inhibition, Natural Products Synthesis, and Molecular Imaging: An Approach to Chemical Biology by Synthetic Chemists

Exploring a Unique Reactivity of 6π-Azaelectrocyclization to Enzyme Inhibition, Natural Products Synthesis, and Molecular Imaging: An Approach to Chemical Biology by Synthetic Chemists

New strategy in synthetic biology: from enzyme inhibition and natural products synthesis to PET imaging by 6π‐azaelectrocyclization

Synthetic Studies toward Bi-linderone Lead To Unexpected 6π-Electrocyclization Reactions: A Facile Construction of Highly Congested Spiro Compounds

Contact Info

Product

Resources

About