Stereoselective iodocyclopropanation of terminal alkenes with iodoform, chromium(II) chloride, and N,N,N',N'-tetraethylethylenediamine.
Chemoselectivity of a reagent for (E)-olefination of aldehydes derived by reduction of iodoform with chromium(II) chloride in THF changes markedly by addition of TEEDA (N,N,N',N'-tetraethylethylenediamine), and trans-iodocyclopropanes are produced stereoselectively from terminal alkenes by treatment with the base-added reagent system. The iodocyclopropanation occurs only at terminal double bonds, and di- and trisubstituted double bonds in the same molecules remained unchanged. Such functional groups as alcohol, ether, silyl ether, ester, tertiary amine, and amide groups are compatible with the reaction conditions.
Department of Applied Chemistry, Faculty of Engineering, Okayama University, Tsushima, Okayama 700-8530, Japan. ktakai@cc.okayama-u.ac.jp
Kazuhiko
K
Takai
Shota
S
Toshikawa
Atsushi
A
Inoue
Ryo
R
Kokumai