Tungsten carbonyl complexes alkenes

The unhindered phospha-alkene (175) has been characterised in solution as a complex involving ir-donation from the double bond to a tungsten carbonyl acceptor. This complex reacts with 1,3-dienes to give adducts e.g. (176), in which the phosphorus atom... 

Bis(adamantylimido) compounds, with monomeric chromium(VI) complexes, 5, 348 Bis(alkene) complexes conjugated, Rh complexes, 7, 214 mononuclear Ru and Os compounds, 6, 401 -02 in Ru and Os half-sandwich rj6-arenes, 6, 538 with tungsten carbonyls and isocyanides, 5, 685 Bis(u-alkenylcyclopentadienyl) complexes, with Ti(II), 4, 254 Bis(alkoxide) nitrogen-donor complexes, with Zr(IV), 4, 805 Bis(alkoxide) titanium alkynes, in cross-coupling, 4, 276 Bis(alkoxo) complexes, with bis-Cp Ti(IV), 4, 588 Bis[alkoxy(alkylamino)carbene]gold complexes, preparation, 2, 288... 

Heterometal alkoxide precursors, for ceramics, 12, 60-61 Heterometal chalcogenides, synthesis, 12, 62 Heterometal cubanes, as metal-organic precursor, 12, 39 Heterometallic alkenes, with platinum, 8, 639 Heterometallic alkynes, with platinum, models, 8, 650 Heterometallic clusters as heterogeneous catalyst precursors, 12, 767 in homogeneous catalysis, 12, 761 with Ni—M and Ni-C cr-bonded complexes, 8, 115 Heterometallic complexes with arene chromium carbonyls, 5, 259 bridged chromium isonitriles, 5, 274 with cyclopentadienyl hydride niobium moieties, 5, 72 with ruthenium—osmium, overview, 6, 1045—1116 with tungsten carbonyls, 5, 702 Heterometallic dimers, palladium complexes, 8, 210 Heterometallic iron-containing compounds cluster compounds, 6, 331 dinuclear compounds, 6, 319 overview, 6, 319-352... 

Hydrosulfides, in tungsten carbonyl and isocyanide complexes, 5, 644 Hydrotelluration alkenes, 9, 608 alkynes, 9, 604... 

The role of transition-metal carbonyls and particularly those of the Group 6 metals in homogeneous photocatalytic and catalytic processes is a matter of considerable interest [1]. UV irradiation especially provides a simple and convenient method for generation of thermally active co-ordinately unsaturated catalyst for alkenes or alkynes transformation. By using tungsten and molybdenum carbonyl compounds as catalysts, alkenes and alkynes can be metathesized, isomerised and polymerized. Photocatalytic isomerization of alkenes in the presence of molybdenum hexacarbonyl was observed by Wringhton thirty years ago [2]. Carbonyl complexes of molybdenum catalyze not only... 

The anti addition of amines to the double bond of cationic (alkene)(cyclopentadienyl)di-carbonyliron complexes and to the analogous molybdenum and tungsten complexes has been reported31 33. The adducts underwent carbonyl insertion-cyclization to give chelate complexes, which were then oxidized to /8-lactams. For example, from the Fp complexes of ( )- and (Z)-2-butene the corresponding /8-lactams were obtained diastereoselectively in 10-15% yield by the direct oxidation of the benzylamine adducts with chlorine at low temperature33. The stereochemistry was determined by H-NMR spectroscopy. 

Chromium, Molybdenum, and Tungsten.— Applications of benchrotrenes and analogous Mo complexes in organic synthesis have been reviewed, and studies of the use of such complexes as catalysts for alkene polymerization, isomerization, and hydrogenation have been reported. Decomplexation of the arene ligand of benchrotrenes can be conveniently effected by treatment with boiling pyridine. Spectroscopic studies of ( -arene)M(CO)3 complexes have been described, including discussions of carbonyl vibrational spectra, ih 2 and... 

Iwasawa et al. developed a tungsten-mediated benzannulation reaction (Scheme 15.15). On treatment of o-ethynylphenyl ketones 11 with 3 equiv of preformed W(C0)5(THF), followed by the addition of electron-rich alkenes 8, such as enam-ines and enol ethers, the corresponding naphthalenes 19 were produced together with W(CO)6 [26]. Ohe, Miki, and co-workers prepared pyranyUdene-metal complexes from conjugated enyne-carbonyl compounds using Mo, W, and Cr complexes, which were treated with dimethyl acetylenedicarboxylate to give benzene derivatives [27]. 

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