Internal delivery of soft chlorine and bromine atoms: stereoselective synthesis of (E)-beta-halogenovinyl(aryl)-lambda3-iodanes through domino lambda3-iodanation-1,4-halogen shift-fluorination of alkynes.
4-(Difluoroiodo)toluene-induced domino lambda(3)-iodanation-1,4-halogen shift-ring enlargement-fluorination reaction of 5-halopentynes with a four-, five-, or six-membered carbocycle afforded the ring-expanded (E)-delta-fluoro-beta-halovinyl-lambda3-iodanes stereoselectively in high yields, probably via the intermediacy of five-membered halonium ions. Use of internal alkynes makes it possible to synthesize tetrasubstituted beta-halovinyl-lambda(3)-iodanes with defined stereochemistry.
Ochiai
Masahito
M
Graduate School of Pharmaceutical Sciences, University of Tokushima, 1-78 Shomachi, Tokushima 770-8505, Japan. mochiai@ph.tokushima-u.ac.jp
Hirobe
Masaya
M
Yoshimura
Akira
A
Nishi
Yoshio
Y
Miyamoto
Kazunori
K
Shiro
Motoo
M
D000480:Alkynes / Q000737:chemistry*; D001966:Bromine; D002713:Chlorine; D005461:Fluorine; D006219:Halogens / Q000737:chemistry*; D007455:Iodine / Q000737:chemistry; D013237:Stereoisomerism
D000480:Alkynes; D006219:Halogens; D005461:Fluorine; D002713:Chlorine; D007455:Iodine; D001966:Bromine