This invention solves the problem of providing an efficient, new method for producing a fluoromethylene-containing compound. The problem can be solved by a method for producing a compound represented by formula (1) or a ring-closed or ring-opened derivative of the compound, wherein R
1
represents an organic group, R
X
represents hydrogen or fluorine, R
2a
, R
2b
, R
2c
, and R
2d
are the same or different, and each represents —Y—R
21
or —N(—R
22
)
2
, or R
2b
and R
2c
may join together to form a bond, wherein Y represents a bond, oxygen, or sulfur, R
21
represents hydrogen or an organic group, and R
22
, in each occurrence, is the same or different and represents hydrogen or an organic group; the method comprising step A of reacting a compound represented by formula (2), wherein X represents a leaving group, and other symbols are as defined above, with a compound represented by formula (3), wherein the symbols are as defined above, in the presence of a reducing agent under light irradiation.
When ArCF2Cl was reacted with PhSeNa in DMF in the presence of light, it was found that a SRN1 type reaction occurred to give ArCF2SePh. As the reaction did not proceed without light, the substitution reaction should be initiated by photo-induced electron transfer from PhSe− to ArCF2Cl. The cleavage of the C–Cl bond of PhCF2Cl by one-electron reduction with samarium(II) iodide to give a PhCF2 radical and chloride ion was also observed. The PhCF2 radical, thus formed, was trapped by styrene and phenylacetylene before it was reduced to PhCF2 anion. UHF/3-21G calculation demonstrated that one-electron reduction in PhCF2Cl led the spontaneous dissociation of the C–Cl bond to the PhCF2 radical and Cl−, but the PhCF3 radical anion existed as a stable form.
Reductive Conversion of Chlorodifluoromethylbenzene with Samarium(II) Diiodide
作者:Masato Yoshida、Daiki Suzuki、Masahiko Iyoda
DOI:10.1246/cl.1994.2357
日期:1994.12
PhCF2Cl suffered readily one-electron reduction with SmI2 to give PhCF2 radical and chloride ion. The resulting PhCF2 radical was further reduced with SmI2 to PhCF2SmI2 which reacted with electrophile such as Me3SiCl. The initially formed PhCF2 radical could be trapped by olefin or acetylene before it was reduced to PhCF2SmI2.