Intermediate Steps of the Wittig Reaction with Non-Stabilized Phosphorylides

Phosphorylide complexes, Li+[Ph3P+C-HR]X-, where R = H, alkyl, or alkoxy, gives very poor yields of olefins from aldehydes in the Wittig reaction. In the presence of 1.1 equivs. tert-BuOK the reaction is strongly accelerated. By this method methylenecyclohexane, styrene, w-methylstyrene, w,w-dimethylstyrene, 4-octene, 1-phenyl-1-hexene, and 1,1-diphenylethylene, resp., are prepd. in 60-91% yields by treating cyclohexanone, BzH, BzH, BzH, butyraldehyde, BzH, and BzPh, resp., at 22 Deg 0.5-15.0 h. It is postulated that the intermediate [Ph2P+CHRCH(O-Li+)R']X- reacts to give the K+ deriv., which dissocs. more easily to Ph3P+CHRCHO-R', necessary for the formation of I, which gives RCH:CHR' and Ph3PO. [on SciFinder (R)]

Published in:
Angewandte Chemie, International Edition, 3, 636-637
CAN 61:61417 35 Noncondensed Aromatic Compounds Univ. Heidelberg,Germany. Journal language unavailable. 6704-79-6 (2-Pentene, 4-phenyl-); 7614-93-9 (1-Butene, 1,3-diphenyl-); 35192-31-5 (1-Butene, 1,3-di-o-tolyl-); 50704-01-3 (2-Pentene, 2-methyl-4-phenyl-); 60043-58-5 (2-Pentene, 2,4-diphenyl-); 76263-89-3 (1-Butene, 1-(p-chlorophenyl)-3-phenyl-); 87331-33-7 (1-Butene, 1-phenyl-3-o-tolyl-); 87331-36-0 (1-Butene, 3-phenyl-1-o-tolyl-); 91801-84-2 (3-Hexene, 2-phenyl-); 92104-75-1 (2-Hexene, 2-methyl-4-phenyl-); 92104-76-2 (2-Pentene, 2,3-dimethyl-4-phenyl-); 92104-77-3 (2-Pentene, 2,4-dimethyl-4-phenyl-); 92907-71-6 (1-Butene, 1-(2,5-dichlorophenyl)-3-phenyl-); 93162-85-7 (2-Pentene, 4-(p-tert-butylphenyl)-2-methyl-); 93228-12-7 (Propyne, 1-phenyl-2,3-13C2); 93536-66-4 (2-Heptene, 2-methyl-4-phenyl-); 95022-71-2 (2-Pentene, 4-(p-tert-butylphenyl)-2,3-dimethyl-); 96173-76-1 (3-Eicosene, 2-phenyl-) (prepn. of); 1530-33-2 (Phosphonium, isopropyltriphenyl-, bromide); 21406-61-1 (Phosphonium, pentyltriphenyl-, bromide); 39895-79-9 (Phosphonium, ethyltriphenyl-) (reaction with benzaldehyde); 15912-74-0 (Phosphonium, methyltriphenyl) (reaction with benzaldehyde and cyclohexanone); 32589-80-3 (Phosphonium, tetramethyl-) (reaction with benzophenone); 22444-89-9 (Phosphonium, butyltriphenyl-) (reaction with butyraldehyde); 108-94-1 (Cyclohexanone) (reaction with methyltriphenylphosphonium bromide); 119-61-9 (Benzophenone) (reaction with tetramethylphosphonium iodide); 100-52-7 (Benzaldehyde) (reactions of, with alkyltriphenylphosphonium bromides)

 Record created 2006-03-03, last modified 2018-01-27

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