Tandem [4+2]/retro[3+2]/[3+2] cycloaddition reactions of fluorinated‐oxadiazoles with conjugated, unconjugated, cyclic, and acyclic dienes DOI Open Access
Joshua Atta‐Kumi, George Baffour Pipim, Ernest Opoku

et al.

Journal of Physical Organic Chemistry, Journal Year: 2023, Volume and Issue: 37(1)

Published: Oct. 2, 2023

Abstract The tandem reactions of 2,5‐bis(trifluoromethyl)‐1,3,4‐oxadiazole with conjugated, unconjugated, acyclic, and cyclic dienes have been studied at the M06‐2X/6‐311++G(d,p) level theory. rate‐determining step is initial [4+2] cycloaddition in reaction cyclic, unconjugated dienes, whereas stereochemistry adduct determined by [3+2] step. exo ‐coupling kinetically favored over endo 2,5‐(bis‐trifluoromethyl)‐1,3,4‐oxadiazole all considered dienes. In retro (N 2 extrusion), higher activation energy required to furnish carbonyl ylide conjugated as compared acyclic At step, intermolecular addition intramolecular both or proceeds low energies when are participating, those Overall, process via an asynchronous one‐step mechanism coupling ‐ ‐cycloaddition fashion, followed a [3+2], which extrudes N , then stereo‐determining leads products. polarity inter‐ intra‐molecular steps can be influenced two factors: nature heteroatom present on diene molecule size diene. These factors play role determining reactivity electron distribution within diene, thereby impacting overall reactions.

Language: Английский

cis-Selective [5＋2]-Cycloaddition Reactions of Cyclic Morita-Baylis- Hillman Alcohols and Its Analogues with Arylethylenes Catalyzed by Ag(I) DOI

Yongwei Cui,

Chunmiao Liang,

Hai‐Tao Zhu

et al.

Chinese Journal of Organic Chemistry, Journal Year: 2024, Volume and Issue: 44(5), P. 1535 - 1535

Published: Jan. 1, 2024

Language: Английский

Citations

0
Enantioselective Cascade Catalysis for the Construction of Tetrahydroquinolines DOI
Yan Ren, Na Li, Song Liu

et al.

Organic Letters, Journal Year: 2024, Volume and Issue: 26(44), P. 9448 - 9454

Published: Oct. 30, 2024

Secondary amines are widely used as robust catalysts for the enantioselective functionalization of aldehydes, yet they rarely employed Lewis bases or hydrogen-bonding alkene activation. In this study, we present a decarboxylative [4 + 2] cycloaddition vinyl benzoxazinanones with nitroolefins to construct tetrahydroquinolines through cascade catalysis. A single chiral morpholine catalyst sequentially functions both base and catalyst. These activation modes effectively drive process control stereochemistry.

Language: Английский

Citations

0
The [4+2] Annulation of o-Acylamino-aryl MBH Carbonates with Coumarins: Facile Access to Tetrahydrochromeno[4,3-b]quinolin-6-ones DOI

Min Amy Xiang,

Gang-Yong Liu,

Huimei Liu

et al.

New Journal of Chemistry, Journal Year: 2024, Volume and Issue: 49(3), P. 683 - 686

Published: Dec. 16, 2024

This study presents a [4+2] annulation reaction with o -acylamino-aryl MBH carbonates and coumarins, yielding tetrahydrochromeno[4,3- b ]quinolin-6-ones up to 95% efficiency excellent substrate tolerance.

Language: Английский

Citations

0
Asymmetric organocatalytic Morita−Baylis−Hillman reaction and asymmetric organocatalytic transformations of Morita−Baylis−Hillman adducts. An update DOI

Hélène Pellissier

Tetrahedron, Journal Year: 2024, Volume and Issue: 172, P. 134435 - 134435

Published: Dec. 23, 2024

Language: Английский

Citations

0
Tandem [4+2]/retro[3+2]/[3+2] cycloaddition reactions of fluorinated‐oxadiazoles with conjugated, unconjugated, cyclic, and acyclic dienes DOI Open Access
Joshua Atta‐Kumi, George Baffour Pipim, Ernest Opoku

et al.

Journal of Physical Organic Chemistry, Journal Year: 2023, Volume and Issue: 37(1)

Published: Oct. 2, 2023

Abstract The tandem reactions of 2,5‐bis(trifluoromethyl)‐1,3,4‐oxadiazole with conjugated, unconjugated, acyclic, and cyclic dienes have been studied at the M06‐2X/6‐311++G(d,p) level theory. rate‐determining step is initial [4+2] cycloaddition in reaction cyclic, unconjugated dienes, whereas stereochemistry adduct determined by [3+2] step. exo ‐coupling kinetically favored over endo 2,5‐(bis‐trifluoromethyl)‐1,3,4‐oxadiazole all considered dienes. In retro (N 2 extrusion), higher activation energy required to furnish carbonyl ylide conjugated as compared acyclic At step, intermolecular addition intramolecular both or proceeds low energies when are participating, those Overall, process via an asynchronous one‐step mechanism coupling ‐ ‐cycloaddition fashion, followed a [3+2], which extrudes N , then stereo‐determining leads products. polarity inter‐ intra‐molecular steps can be influenced two factors: nature heteroatom present on diene molecule size diene. These factors play role determining reactivity electron distribution within diene, thereby impacting overall reactions.

Language: Английский

Citations

1