T. Shigeoka et al., Synthesis of new fluorovinylzinc reagents and their application for synthesis of fluorine analogs of protoporphyrin, J FLUORINE, 103(2), 2000, pp. 99-103
Treatment of chlorotrifluoroethene (4) or 2-chloro-1, 1-difluoroethene (5)
with sec-butyllithium in the presence of zinc chloride gave new fluorovinyl
zinc reagents (12 or 13). These were distinguished by F-19 NMR from triflu
orovinylzinc chloride (7) or 1-chloro-2,2-difluorovinylzinc chloride (8) ob
tained by Normant's group, via preliminary formation of fluorinated vinylli
thium reagents by treatment of 4 or 5 with sec-butyllithium followed by add
ition of zinc chloride. Reaction of 12 or 13 with 3,8-diiododeuteroporphyri
n dimethyl eater (9) in the presence of a palladium catalyst produced 3,8-b
is(trifluorovinyl) or 3,8-bis(1-chloro-2,2-difluorovinyl)deuteroporphyrin d
imethyl eater (10 or 11) quantitatively, while the same reaction of metal c
omplex of 9 with the reagents (7 or 8) formed by Normant's method gave 10 o
r 11 in the yields of 23 or 56%, respectively. (C) 2000 Elsevier Science S.
A. All rights reserved.