The cross-couplingreaction of allylic carbonates with organosilanes was found to proceed without fluoride ion activation under mild conditions by using a coordinatively unsaturated palladium complex as a catalyst. The reaction was assumed to proceed through an allylpalladium alkoxide derived from the allylic carbonate substrate and a palladium(0) species, the alkoxo ligand activating the organosilicon
Alkenylfluorosilanes, phenylfluorosilanes or alkynylsilanes smoothly
dimerize in the presence of a copper(I) salt in a polar solvent
such as N,N-dimethylformamide (DMF) or dimethyl sulfoxide (DMSO)
to give the 1,3-conjugated dienes, biphenyl or 1,3-conjugated diynes,
respectively.
Alkenylfluorosilanes smoothly underwent cross-coupling reaction with allylic carbonates in the presence of a palladiun catalyst and in the absence of fluoride ion to give 1,4-dienes in good yields with retention of configuration.
A wide range of organosilicon compounds couples with enol and aryl triflates in the presence of Pd catalyst and fluoride ion
作者:Yasuo Hatanaka、Tamejiro Hiyama
DOI:10.1016/s0040-4039(00)94682-3
日期:1990.1
Synthesis of 5-Substituted Pyrimidine Nucleosides through a Palladium-catalyzed Cross-Coupling of Alkenylhalosilanes
Palladium-catalyzed cross-coupling of alkenylhalosilanes with 5-iodouracil and 5-iodouridine derivatives was described. 5-Iodo-1,3-dimethyluracil coupled with alkenylfluorodimethylsilanes to give the corresponding cross-coupled products in good yield. Fully protected 5-iodo-2'-deoxyuridine derivative also underwent the cross-coupling reaction. Noteworthy is that unprotected 5-iodo-2'-deoxyuridine could be converted into the corresponding cross-coupled products in good yields using alkenyl(difluoro)methylsilanes.