Asymmetric Photoinduced 1,4-Selective Allylation of α,β-Unsaturated Aldehydes through Organocatalysis

Experimentally, a reversal of chemoselectivity has been observed in catalyzed Diels–Alder reactions of α,β-unsaturated aldehydes (e.g., (2E)-but-2-enal) and ketones (e.g., 2-hexen-4-one) with cyclopentadiene. Indeed, using the triflimidic Brønsted acid Tf2NH as catalyst, the reaction gave a Diels–Alder adduct derived from α,β-unsaturated ketone as a major product. On the other hand, the use of tris(pentafluorophenyl)borane B(C6F5)3 bulky Lewis acid as catalyst gave mainly the cycloadduct of α,β-unsaturated aldehyde as a major product. Our aim in the present work is to put in evidence the role of the catalyst in the reversal of the chemoselectivity of the catalyzed Diels–Alder reactions of (2E)-but-2-enal and 2-Hexen-4-one with cyclopentadiene. The calculations were performed at the ωB97XD/6-311G(d,p) level of theory and the solvent effects of dichloromethane were taken into account using the PCM solvation model. The obtained results are in good agreement with experimental outcomes.

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ChemInform Abstract: A NOVEL SYNTHESIS OF α,β-UNSATURATED ALDEHYDES AND ESTERS BY DYE-PHOTOOXYGENATION OF METHYL ENOL ETHERS

Chemischer Informationsdienst ◽

10.1002/chin.197818124 ◽

1978 ◽

Vol 9 (18) ◽

Author(s):

G. ROUSSEAU ◽

P. LE PERCHEC ◽

J. M. CONIA

Keyword(s):

Enol Ethers ◽

Unsaturated Aldehydes ◽

Novel Synthesis

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Assembly of Fluorinated Chromanones via Enantioselective Tandem Reaction

Chemical Communications ◽

10.1039/d1cc01187a ◽

2021 ◽

Author(s):

Mengxue Lu ◽

Zongli Xiong ◽

Yuqiao Zhou ◽

Xin Wang ◽

Xiaoyi Li ◽

...

Keyword(s):

Enantioselective Synthesis ◽

Tandem Reaction ◽

Unsaturated Aldehydes ◽

Stereogenic Centers ◽

First Time

The enantioselective synthesis of fluorinated tricyclic chromanones with multiple vicinal stereogenic centers has been realized for the first time, through the tandem reaction between 2-fluorinated 1-(2-hydroxyaryl)-1,3-diketones and α,β-unsaturated aldehydes. In...

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ChemInform Abstract: CYCLOADDITIONS OF DIAZOESTERS TO α,β-UNSATURATED ALDEHYDES

Chemischer Informationsdienst ◽

10.1002/chin.197910095 ◽

1979 ◽

Vol 10 (10) ◽

Author(s):

A. F. NOELS ◽

J. N. BRAHAM ◽

A. J. HUBERT ◽

PH. TEYSSIE

Keyword(s):

Unsaturated Aldehydes

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Platinum and cobalt intermetallic nanoparticles confined within MIL-101(Cr) for enhanced selective hydrogenation of the carbonyl bond in α,β-unsaturated aldehydes: synergistic effects of electronically modified Pt sites and Lewis acid sites

Catalysis Science & Technology ◽

10.1039/d0cy02082f ◽

2021 ◽

Author(s):

Muhammad Zahid ◽

Jiang Li ◽

Ahmed Ismail ◽

Francisco Zaera ◽

Yujun Zhu

Keyword(s):

Synergistic Effect ◽

Reduction Method ◽

Synergistic Effects ◽

Acid Sites ◽

Lewis Acid Sites ◽

Unsaturated Aldehydes ◽

Uniform Dispersion ◽

Carbonyl Bond ◽

Method Show ◽

Intermetallic Nanoparticles

PtCo/MIL-101(Cr) with high uniform dispersion Pt–Co IMNs synthesized by a polyol reduction method show higher activity for selective catalytic hydrogenation of α,β-unsaturated aldehydes due to the synergistic effect of PtCo and MIL-101(Cr) support.

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