Chromium Hexacarbonyl Isomerisation of Ergosterol and Related Dienes

Author(s):  
Derek H. R. BARTON ◽  
Stephen G. DAVIES ◽  
William B. MOTHERWELL
1995 ◽  
Vol 14 (2) ◽  
pp. 640-649 ◽  
Author(s):  
Christian Amatore ◽  
Paul J. Krusic ◽  
Steen U. Pedersen ◽  
Jean-Noeel Verpeaux

1984 ◽  
Vol 39 (2) ◽  
pp. 207-212 ◽  
Author(s):  
Karl Dimroth ◽  
Rüdiger Thamm ◽  
Hans Kaletsch

New 6π-tricarbonylchromiumpyrnftne complexes 5c and 5d could be synthesized from 2,6-di-rbutyl- and 2,4,6-tri-f-butylpyridines (3c and 3d) with chromium hexacarbonyl. They are characterized by their 1H and 13C NMR Spectra and their CO-frequencies which are rather similar to those of 6π-tricarbonylchromium-2,4 ,6-triphenyl [1] or 2,4,6-trw-butyl- [2] λ3-phosphorins. When 5d is reacted with lithiumphenyl, the phenyl residue adds to C-4, giving probably compound 7, which by methanolysis and allyl rearrangement of the hydrogen atom from position 4 to position 2 affords tricarbonylchromium-2,6-di-f-butyl-4-phenyl-1,2-dihydropyridine (8) in 56% yield. The 6π-tricarbonylchromium complexes of 2,4,6-triphenyl- or 2,4,6-tn-t-butyl-λ3-phosphorins react with lithiumorganic compounds by addition only to the phosphorus atom whose reaction with methyliodide lead to tricarbonylchromium-λ5-phosphorin-ylid complexes [2], 5 d is a well crystallized compound, the X-ray analysis of the first 6π-tricarbonylchromium pyridine derivate could be performed [3] and compared with the results of the X-ray analysis of 6π-tricarbonylchromiumx 2,4,6-triphenyl-λ3-phosphorin [4]


1983 ◽  
Vol 105 (7) ◽  
pp. 1769-1772 ◽  
Author(s):  
L. G. Vanquickenborne ◽  
J. Verhulst

1985 ◽  
Vol 40 (10) ◽  
pp. 1314-1319 ◽  
Author(s):  
Heribert Wadle ◽  
Kurt Dehnicke ◽  
Dieter Fenske

Trithiazylchloride, (NSCl)3, reacts with metallic chromium, with chromium hexacarbonyl, with CrCl3·3 thf, as well as with chromium(VI) oxide to form mixtures, in which S4N3⊕ [CrCl4(N2S2)]⊖ can be identified as the major product. This compound reacts with tetraphenylarsonium chloride in dichloromethane to form the title compound, which we have characterized by IR spectroscopy and an X-ray crystal structural analysis. (AsPh4)4[CrCl4(N2S2)]4·8 CH2Cl2 crystallizes monoclinically in the space group C2/c with four formula units per unit cell and with the following lattice constants at -100 °C: a = 2146, b = 2033, c = 3137 pm; β = 96.0° (9918 independent observed reflexions, R = 0.064). The compound consists of AsPh4⊕ ions, tetrameric anions [CrCl4(N2S2)]44⊖ and included CH2Cl2 molecules. The chromium atoms of the anions occupy the corners of a nearly ideal square; they are connected via the N-atoms of planar N2S2-rings, which are oriented perpendicularly to the Cr4-plane. The chromium atoms complete their distorted octahedral coordination with four terminal chlorine atoms, the axial ones of which form short Cl···S-contacts of average 310 pm to the S-atoms of the N2S2-rings.


Sign in / Sign up

Export Citation Format

Share Document