Browsing by Author "Kimura, Yuki"

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Bromine-Radical-Mediated Synthesis of -Functionalized ,- and ,epsilon-Unsaturated Ketones via C-H Functionalization of Aldehydes
(2017-09-01)
Kippo, Takashi
;
Kimura, Yuki
;
Ueda, Mitsuhiro
;
Fukuyama, Takahide
;
Ryu, Ilhyong
The bromine-radical-mediated allylation reaction of aldehydes was studied. In the presence of V-65 as radical initiator, the reaction of aldehydes with allyl bromides gave beta,gamma-unsaturated ketones in good yields (13 examples, 45-84%). The reaction is triggered by hydrogen abstraction from the aldehyde by bromine radical to form an acyl radical, which undergoes an S(H)2'-type addition-elimination reaction with allyl bromides to give coupling products with liberation of bromine radical. Three-component coupling reactions comprising aldehydes, electron-deficient alkenes, and methallyl bromide also proceeded to give delta,epsilon-unsaturated ketones.