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Abstract We report the oxidative dimerization reaction of siloxydienes derived from simple enones that creates a new gamma‐gamma (γ‐γ) C−C bond using catalytic iron and benzoyl peroxide as the terminal oxidant in acetonitrile solvent at ambient temperature. The reaction shows a broad substrate scope including cyclic and acyclic siloxydienes derived from ketones, aldehydes, and esters, which are converted to 1,8‐dicarbonyl compounds under mild catalytic reaction conditions in 19–89 % yield across 30 examples. The method is suitable for the coupling of sterically demanding carbon centers, including the formation of vicinal quaternary centers. Conceptually, the dienol ether serves as a precursor to a conjugated radical cation, which undergoes highly site selective γ‐dimerization reactions. The γ‐γ dimerization strategy is applied to the synthesis of a bioactive analogue of honokiol.
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Remote Fluorination of α,β‐Unsaturated Carbonyls via Silyl Dienol Ethers
Abstract We report a general, regioselective, and metal free γ‐fluorination of α,β‐unsaturated carbonyls via silyl dienol ethers that are readily prepared from simple ketones and aldehydes. The transformation displays broad scope including 27 cyclic and acyclic siloxydienes providing γ‐fluoro compounds in 28–91 % yield. Notably, the reported conditions are also suitable for the synthesis of challenging tertiary fluorides. The regioselectivity of the reaction was studied on a series of acyclic siloxydienes and was observed to be sensitive to the conformational flexibility of the substrate. Diversification of the γ‐fluorocarbonyls demonstrates the promise of fluorine as a stereocontrol element.
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- Award ID(s):
- 2154880
- PAR ID:
- 10642348
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Chemistry – A European Journal
- Volume:
- 30
- Issue:
- 26
- ISSN:
- 0947-6539
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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