Chromium tricarbonyl naphthalene

A few Cr(0) complexes were reported to catalyze the Kharasch addition of polyhalocarbons to olefins. (Naphthalene)chromium tricarbonyl exhibited low to moderate activity in additions of tetrachloromethane to olefins. The reactions were proposed to occur by a non-radical mechanism [215]. A later kinetic study showed that a radical mechanism operates (see Sect. 7) [216, 217]. Shvo et al. used 5 mol% Cr(CO)6 in acetonitrile to add tetrachloromethane to 1-octene [218]. It was necessary to transform the precatalyst first to the active catalyst... 

Decomplexation of complex 15 by exposure to sunlight in ethereal solution affords the optically active free amino alcohol 18 in 90% yield, as described in Protocol 8. It is worth noting that recomplexation of this compound 18 by a ligand-transfer reaction with Ti -naphthalene chromium tricarbonyl did not give rise to the precursor 15 but to its diastereoisomeric complex in which the opposite face of the ring is coordinated to the chromium moiety. In this... 

Chromium hexacarbonyl offers a highly regioselective method for the isomerization of cisoid 1,3-dienes to transoid dienes (eq 6). (Naphthalene)chromium tricarbonyl catalyzes isomerization of silyloxymethylbutadiene derivatives to silyl dienol ethers in quantitative yields via a U-shaped pentadienyl intermediate (eq7). ... 

Irradiation of complex 6 in the presence of ethyl acrylate provides the [6 + 2] 7t-adduct 9 as the single enrfo-diastereomer,276 which may also be obtained by heating a mixture of methyl l//-azepine-l-carboxylate with the ester in the presence of a catalytic amount of tricarbonyl(>]6-naphthalene)chromium(O).277... 

Tricarbonyl(naphthalene)chromium, 19 Tungsten carbonyl, 49 Metal-containing compounds Aluminum Compounds Alkylaluminum halides, 5, 25, 44, 173, 306... 

Tricarbonyl(naphthalene)chromium, 19 Trimethylsilyl chlorochromate, 327 Cobalt Compounds Acylcobaltate complexes, 101 [Bis(salicylidene-y-iminopropyl)methyl-amine]cobalt(II), 41 Cobalt(II) chloride, 249 Cobalt zeolites, 296 Dicarbonylcyclopentadienylcobalt, 96 Di- x-carbonylhexacarbonyldicobalt,... 

A number of substituted benzenes, naphthalenes, indans, pyridmes, and indoles form arene(tricarbonyl)chromium complexes upon thermolysis under an inert atmosphere, usually in a high boiling ether, or by irradiation of the arenes in the presence of chromium hexacarbonyl. The complexes are relatively air-stable and can usually be stored for long periods in the absence of light. Somewhat milder conditions can be used by transfer of the chromium tricarbonyl group from preformed naphthalene(tricarbonyl)chromium, tris(L)tricarbonyl chromium (L = acetonitrile, ammonia, pyridine), or tricarbonyl( -l-methylpyrrole)chromium. Enan-tiomerically pure arene(tricarbonyl)chromium complexes having two different substituents, either ortho or meta can be prepared conveniently by classical resolution of racemic... 

Complexation of dihydronaphthalene with chromium tricarbonyl facilitates the attack of a nucleophilic amine and stereoselectively directs the protonation "anti" to the metal atom. (+)-(l S,2 R)-, 2-Dihydro-7-methoxy-1,4-dimethyl-1 - 2 -[methyl(trifiuoroacetyl)amino]propyl -naphthalene [(+)-7] was treated with chromium hexacarbonyl to give a mixture of a- and /(-chromium tricarbonyl complexes in a 10 1 ratio ( H NMR). The complexes were separated and the a-isomer cyclized by base treatment and sonication. Dccomplexation gave the ben-zomorphan tricycle 8 in low yield [40%, based on recovered (+)-7]18. The trifluoroacetyl protection of the amino group was necessary to achieve both stereoselective complexation with chromium tricarbonyl and successful cyclization. 

Staggered configurations have also been observed for the tricarbonyl chromium complexes of phenanthrene 294, 295), 9,10-dihydro-phenanthrene 293, 295), anthracene 202), naphthalene 262), and 1-aminonaphthalene 58). The eclipsed configuration has been observed for the tricarbonyl complexes of anisole (57, 229), toluidine 60, 61), methylbenzoate (59), o-methoxyacetylbenzene, o-hydroxyacetylbenzene 101), 2-methoxy-[l-hydroxy-ethyl]benzene (99), and 2-methyl-[l-hydroxy-l-phenylpropyl]benzene (97). It is apparent that the orientation of the chromium tricarbonyl moiety is in many cases controlled by the substituents on the ring to which it is coordinated, and this has been attributed to mesomeric electron repulsion or withdrawal by the substituents 374). 

An overview of the effect of catalyst in the reaction of arenes with chromium hexacarbrmyl has been published. The reactivity of 17-, 18-, and 19-etectron catkMis generated electrochemically from mesitylene-tungsten tricarbonyl has been examined. The gas phase ion chemistry of a range of arene tricarbonylchromium complexes has been investigated by F.T. mass spectrometry. An improved synthesis of substituted naphthalene chromium carbonyls has appeared. ... 

The synthesis of the arene-chromium-tricarbonyl complexes proceeds by heating the arene with [Cr(CO)g] in dibutyl ether or, if the arene is thermally fragile, by reaction with another labile complex such as [Cr(naphthalene)(CO)3] or [CrfCOlsLs],... 

Other polymers which have been the subject of thermal degradation studies include ethylene-vinyl acetate [29, 66, 67], ethylene-vinyl alcohol [68], poly(aryl-ether ketone) [69], poly-2-vinyl-naphthalene-co-methyl maleate [34], polyphenylenes based on diethyl-benzophenone [70], polyglycollide [71-73], poly(a-methylstyrene tricarbonyl chromium [74], polytetrahydrofuran [75], polylactide [76-78], poly(vinyl) cyclohexane [79], styrene-vinyl cyclohexane [80], isopropenylacetate-maleic dianhydride [80], polyethylene glycol containing a 1,3-disubstituted phenolic group [81], poly-2-vinyl naphthalene-co-methacrylate [34], collagen biopolymers [82], chitin graft poly (2-methyl-oxazoline - polyvinyl chloride blends [83], cellulose [32, 83-88] and side-chain cholestric elastomers [89, 90]. 

Consider as an example a reaction of the degenerate rearrangement of the 71-complex of chromium naphthalene-tricarbonyl XLIII. It would be natural to assume as an intermediate structure or a transition state the structure XLIIIa in which the group Cr(CO)3 is located between two nuclei on the least-motion path. 

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