Premium
Ring‐Opening Reaction of a Dihydrozirconafuran (= 2,5‐Dihydro‐1,2‐oxazirconole): An equilibrium studied by NMR methods, and its chemical consequences
Author(s) -
Baumann Wolfgang,
Ohff Andreas,
Ebener Michael
Publication year - 1996
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.19960790213
Subject(s) - chemistry , metallacycle , acetone , trimethylsilyl , chemical equilibrium , ring (chemistry) , nuclear magnetic resonance spectroscopy , ligand (biochemistry) , chemical shift , equilibrium constant , dynamic equilibrium , computational chemistry , stereochemistry , medicinal chemistry , organic chemistry , x ray crystallography , biochemistry , physics , receptor , diffraction , optics
The dihydrozirconafuran 3 (2,2‐di(cyclopenta‐2,4‐dien‐l‐yl)‐2,5‐dihydro‐5,5‐dimethyl‐3,4‐bis(trimethylsilyl)‐1,2‐oxazirconole) is a valuable synthetic equivalent to the 14‐electron fragment Cp 2 Zr Throughout this paper, C p =η 5 −C 5 H 5 . The reactions of this metallacycle suppose an equilibrium with an ‘opened’ form [ZrCp 2 (RCCR)(acetone)], the latter paving the way to numerous ligand replacements. In a solution containing the dihydrozirconafuran and acetone, these reactions are reversible and degenerate, and can be studied by NMR methods: by two‐dimensional spectroscopy and by observation of the isotope‐induced chemical shifts that occur upon incorporation of (D 6 )acetone into the metallacycle. The findings give an indirect proof of the described equilibrium.