A new generation of "instant ylides": powder mixtures of phosphonium salts and potassium hydride as storable precursors to Wittig reagents
Mixing a finely pulverized alkyltriphenylphosphonium salt and potassium hydride in 1:1 molar ratio gives a ready-to-use powder the components of which react rapidly when tert-Bu Me ether is added under stirring. When, in general after a few minutes, the generation of the (triphenylphosphonio)alkanide is complete, it can be immediately used for the Wittig olefination of a carbonyl compd. Compared to sodium amide based "instant ylides", the new blends offer little advantage as long as simple phosphonium salts are ingredients but they extend considerably the shelf life of mixts. contg. heterosubstituted derivs. such as methylthiomethyl- or picolyltriphenylphosphonium salts. [on SciFinder (R)]
Keywords: Ylides Role: RCT (Reactant) ; RACT (Reactant or reagent) (mixts. of phosphonium salts and potassium hydride as storable precursors to Wittig reagents); Wittig reaction (with \"instant ylides\") ; ylide instant prepn; Wittig reagent storable precursor; phosphonium salt potassium hydride mixt
General Organic Chemistry
Batiment Chim.,Inst. Chim. Org. l'Univ.,Lausanne-Dorigny,Switz.
written in English.
100-42-5 (Styrene); 100-52-7 (Benzaldehyde); 103-31-1 (4-Styrylpyridine); 351-78-0 ((2-Fluorovinyl)benzene); 622-25-3 (b-Chlorostyrene); 637-50-3 (1-Phenylpropene); 714-08-9 (2-Styrylpyridine); 1608-28-2; 2633-06-9 (3-Styrylpyridine); 2687-12-9; 4747-15-3 ((2-Methoxyvinyl)benzene); 7715-02-8 ([2-(Methylthio)vinyl]benzene); 10276-15-0 (1-Methylthio-3-phenyl-2-propene); 15314-20-2 (4-Methyl-1-phenylpentene); 16277-67-1; 70353-93-4 (1-Fluoro-3-phenyl-2-propene); 96090-09-4 (3-Cinnamylpyridine); 111678-19-4 (4-Cinnamylpyridine); 186032-39-3 (2-Cinnamylpyridine) Role: RCT (Reactant), RACT (Reactant or reagent) (Wittig reaction with \"instant ylide\")
Record created on 2006-03-03, modified on 2016-08-08