O-attack versus N-attack: electrophilic halocyclization of unsaturated amides with vinylic halogen substitution.
Electrophilic iodocyclization of unsaturated amides with an internal vinylic halogen (Cl, Br, or I) substitution afforded exclusively the corresponding cyclic iminoketones via iodolactamization. On the other hand, amides having a terminal vinylic halogen substituent underwent iodolactonization only. Theoretical calculations revealed that the iodocyclization proceeds via the intramolecular iodonium ion transfer from the amide nitrogen to the C=C double bond.
Hu
Tianshun
T
Joint Laboratory of Green Synthetic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 354 Fenglin Road, Shanghai 200032, People's Republic of China.
Liu
Kun
K
Shen
Meihua
M
Yuan
Xinting
X
Tang
Yu
Y
Li
Chaozhong
C
D000577:Amides / Q000737:chemistry*; D003500:Cyclization; D006846:Hydrocarbons, Halogenated / Q000737:chemistry*; D007659:Ketones / Q000138:chemical synthesis* / Q000737:chemistry; D008956:Models, Chemical; D015394:Molecular Structure; D013237:Stereoisomerism
D000577:Amides; D006846:Hydrocarbons, Halogenated; D007659:Ketones