Title of article :
Selective enhancement effects of silver salts on the transition metal-catalyzed synthesis of gem-difluorinated heterocyclics using 2,2-difluorohomopropargyl amides
Author/Authors :
Arimitsu، نويسنده , , Satoru and Bottom، نويسنده , , Rebecca L. and Hammond، نويسنده , , Gerald B.، نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 2008
Pages :
5
From page :
1047
To page :
1051
Abstract :
The addition of silver salts had an effect on the catalyst activity in the Pd(0)-catalyzed cyclization-coupling tandem reaction, as well as in the Rh(I)-catalyzed Pauson–Khand reaction. The cationic palladium complex generated from Pd(PPh3)4 (2.5 mol%) with AgSbF6 (1.5 equiv.) activates the triple bond of 2,2-difluoropropargylic amides to give the 4,5-disubstituted 3,3-difluoro-γ-lactams, through a sequential 5-endo-dig cyclization and cross-coupling reaction. The γ-lactam was transformed into ring-opened monofluorovinylic compounds after silica-gel chromatography. Pauson–Khand reaction of fluorinated 1,7-enyne amides using catalytic amounts of [Rh(COD)2]2 (5 mol%) and AgOTf (20 mol%) gave the corresponding gem-difluorinated bicyclic lactam.
Keywords :
Pauson–Khand , Difluorolactam , Difluoropropargyl , cyclization , amide
Journal title :
Journal of Fluorine Chemistry
Serial Year :
2008
Journal title :
Journal of Fluorine Chemistry
Record number :
1610286
Link To Document :
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