Preparation and Reaction of Quinolinyl (or Pyridinyl)phosphonium Salts with Base and Pivalaldehyde
摘要:
alpha- and gamma-Heteroaryltriphenylphosphonium iodides were prepared by reaction of the corresponding heteroaryl iodides with triphenylphosphine. Reaction of beta-heteroaryl iodides with triphenylphosphine in the presence of a palladium catalyst gave beta-heteroaryltriphenylphosphonium iodides. Elimination of the heteroaryl group was achieved by treating the heteroaryltriphenylphosphonium iodides with a base. Further, the heteroaryl group was trapped with pivalaldehyde to introduce a pivaloyl substituent onto the heteroaromatic ring.
Synthesis of Phosphonium Salts—Phosphine Structure and Inorganic Salts Effects
作者:Mária Mečiarová、Štefan Toma、André Loupy、Branislav Horváth
DOI:10.1080/10426500701545950
日期:2007.12.24
Solvent-free reactions of 2- and 3-halopyridines with PPh3, PBu3, and PCy3 were studied under conventional heating, as well as under microwave irradiation. No difference was observed in the reaction course between classical and microwave reactions. 2-Bromopyridine gave quantitative yields of 2-pyridyltriphenylphosphonium bromide within few minutes at 190 degrees C. Equimolar amounts of some inorganic salts (LiPF6, LiOTf, LiBr NaPF6, KPF6) were necessary for the reactions of the other 2-halopyridines. 3-Halopyridines did not react with PPh3 even in the presence of LiPF6. Their reactions with PCy3 in the presence of LiPF6 resulted in the quantitative formation of dicyclohexylphosphine oxide.
Horner; Hoffmann, Chemische Berichte, 1958, vol. 91, p. 50