ChemInform Abstract: SYNTHESES OF TRIFLUOROMETHYLATED DIENE DERIVATIVES THROUGH THE CLAISEN REARRANGEMENT OF TRIFLUOROMETHYLATED PROPARGYLIC AND ALLYLIC ALCOHOLS

Lanthanide(III)-catalyzed aryl-Claisen rearrangement of substrates bearing halo-substituted allyl groups, specifically 2-bromoallyl aryl ethers, afford ortho-2-bromoallylphenols. Aryl ether substrates were synthesized from brominated allylic alcohols via Mitsunobu reaction, Cu(II)-catalyzed arylation using potassium aryltrifluoroborate salts, or SNAr reaction. Aryl-Claisen rearrangements proceeded in moderate to excellent yields using Eu(III) catalysis. The alkenylbromide functionality remains intact, illustrating the compatibility of synthetically important alkenylhalides during C–O/C–C σ-bond migration processes. Subsequent derivatization of the ortho-2-bromoallylphenol products through O-alkylation or C-arylation/alkenylation via Suzuki–Miyaura cross-coupling demonstrate the potential to access densely-functionalized molecules.

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Base-Mediated Claisen Rearrangement of CF3-Containing Bisallyl Ethers

10.20944/preprints202106.0572.v1 ◽

2021 ◽

Author(s):

Yoko Hamada ◽

Rio Matsunaga ◽

Tomoko Kawasaki-Takasuka ◽

Takashi Yamazaki

Keyword(s):

Palladium Catalyst ◽

Claisen Rearrangement ◽

Allylic Alcohols ◽

Vinyl Ethers ◽

Stepwise Manner ◽

Proton Migration ◽

Allyl Vinyl Ethers

We have previously clarified that the strongly electron-withdrawing CF3 group nicely affected the base-mediated proton migration reactions of CF3-containinig propargylic or allylic alcohols to afford the corresponding a,b-unsaturated or saturated ketones, respectively, which was applied this time to the Claisen rearrangement after O-allylation of the allylic alcohols, followed by isomerization to the corresponding allyl vinyl ethers, enabling the desired rearrangement in a tandem fashion, or in a stepwise manner where a palladium catalyst attained an excellent diastereoselectivity.

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ChemInform Abstract: Regiospecific Synthesis of β,γ-Unsaturated Ketones from Allylic Alcohols. Claisen Rearrangement of α-Allyloxy Ketone Enol Derivatives.

Chemischer Informationsdienst ◽

10.1002/chin.198648166 ◽

1986 ◽

Vol 17 (48) ◽

Author(s):

J. L. C. KACHINSKY ◽

R. G. SALOMON

Keyword(s):

Claisen Rearrangement ◽

Allylic Alcohols ◽

Unsaturated Ketones

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Synthesis of γ,δ-Unsaturated Esters and Amides via Au(I)-Catalyzed Reactions of Aryl Ynol Ethers or Ynamides with Allylic Alcohols

Synthesis ◽

10.1055/a-1559-3020 ◽

2021 ◽

Author(s):

Souta Misawa ◽

Asaki Miyairi ◽

Yoshihiro Oonishi ◽

Steven P. Nolan ◽

Yoshihiro Sato

Keyword(s):

Claisen Rearrangement ◽

Cascade Reactions ◽

Cascade Reaction ◽

Allylic Alcohols ◽

Unsaturated Esters ◽

Mild Conditions ◽

Reaction Proceeds ◽

Ynol Ethers ◽

Catalyzed Reactions ◽

Reaction Attack

Polarized alkynes such as ynol ethers and ynamides have attracted much attention due to their inherent unique reactivity. Herein, we report Au(I)-catalyzed hydroalkoxylation/Claisen rearrangement cascade reactions of aryl ynol ethers and ynamides with allylic alcohols. At the first stage (hydroalkoxylation) of this cascade reaction, attack of allylic alcohols to aryl ynol ethers or ynamides occurs at the α-position of the polarized alkynes in an entirely regioselective manner. Claisen rearrangement of the resulting adducts subsequentially takes place to give γ,δ-unsaturated esters or amides, respectively. The [Au(IPr)NTf2] catalyst is most effective for this reaction, and the reaction proceeds under mild conditions (in the case of aryl ynol ether: in THF, 60 °C; in the case of ynamides: in toluene, 80 °C) in an atom-economical way.

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