Browsing by Author "Hamaoka, Kanako"

Now showing 1 - 2 of 2

Bromine-Radical-Mediated Site-Selective Allylation of C(sp(3))-H Bonds
(2019-03-01)
Ueda, Mitsuhiro
;
Maeda, Ayami
;
Hamaoka, Kanako
;
Sasano, Mika
;
Fukuyama, Takahide
The C(sp(3))-H allylation of alkanes is investigated by using allyl bromides under radical reaction conditions. In many cases, methine C-H allylation preceded methylene and methyl C-H allylation with complete or a high degree of site selectivity. The C-H allylation of allylic compounds, such as allylbenzene, gives 1,5-dienes with the S(H)2' reactions of the allyl radicals occurring at the less hindered carbon.
Bromoallylation of Alkenes Leading to 4-Alkenyl Bromides Based on Trapping of beta-Bromoalkyl Radicals
(2017-10-06)
Kippo, Takashi
;
Hamaoka, Kanako
;
Ueda, Mitsuhiro
;
Fukuyama, Takahide
;
Ryu, Ilhyong
A radical-chain addition of allyl bromides to aryl alkenes, vinyl ester, and vinyl phthalimide was studied in which elusive beta-bromodkyl radicals were trapped efficiently to give 5-bromo-1-pentenes in good to high yields (16 examples). A subsequent carbonylative radical cyclization with AIBN/Bu3SnH/CO was successful in giving the corresponding 3,5-disubstituted cyclohexanone derivatives in moderate yields. Synthesis of a piperidine ring was also successful by subsequent reaction with primary amine.