Premium
New Synthetic Routes to β‐Olefinic Triphenylphosphonium Salts via (Diolefin)tricarbonyliron Complexes
Author(s) -
Salzer Albrecht,
Hafner Andreas
Publication year - 1983
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.19830660616
Subject(s) - chemistry , phosphonium , wittig reaction , allylic rearrangement , reagent , yield (engineering) , moiety , medicinal chemistry , stereospecificity , nmr spectra database , organic chemistry , stereochemistry , catalysis , spectral line , materials science , physics , astronomy , metallurgy
The regio‐ and stereospecific preparation of β‐olefinic triphenylphosphonium salts, starting from (diolefin)tricarbonyliron compounds is described. The latter are converted by various routes into either [(allyl)Fe(CO) 4 ] + ‐ or [(dienyl)Fe(CO) 3 ] + ‐ derivatives. The allylic cations, when reacted with P (C 6 H 5 ) 3 , yield uncomplexed (2‐en‐l‐yl)triphenylphosphonium salts in good yields, while treatment of the dienyl cations with P(C 6 H 5 ) 3 leads to the quantitative formation of (2,4‐diene‐l‐yl)triphenylphosphonium ions still coordinated to the Fe (CO) 3 ‐moiety. A method of oxidative decomplexation is described, by which the free phosphonium salts can be obtained. All new compounds were characterized by 13 C‐NMR spectra and also, where necessary, by 1 H‐NMR decoupling experiments to confirm the stereochemical assignments. Many of the new phosphonium salts, potentially useful as Wittig reagents for natural product syntheses, are difficult to obtain by conventional unequivocal routes.