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Titanium acetylides

The bromoallene (-)-kumausallene (62) was isolated in 1983 from the red alga Laurencia nipponica Yamada [64a], The synthesis of the racemic natural product by Overman and co-workers once again employed the SN2 -substitution of a propargyl mesylate with lithium dibromocuprate (Scheme 18.22) [79]. Thus, starting from the unsymmetrically substituted 2,6-dioxabicyclo[3.3.0]octane derivative 69, the first side chain was introduced by Swern oxidation and subsequent Sakurai reaction with the allylsilane 70. The resulting alcohol 71 was protected and the second side chain was attached via diastereoselective addition of a titanium acetylide. The synthesis was concluded by the introduction of two bromine atoms anti-selective S -substitution of the bulky propargyl mesylate 72 was followed by Appel bromination (tetrabromo-methane-triphenylphosphine) of the alcohol derived from deprotection of the bromoallene 73. [Pg.1011]

Alkynyltriisopropoxytitanium, RC=CTi(0-/-Pr),. These titanium acetylides are prepared by reaction of 1-alkynes with BuLi and ClTi(0-i-Pr)3. [Pg.6]

Titanium acetylides react with 3-benzyl-tetrahydro-l,3-oxazines and 1,3-oxazolidines to give the corresponding / -aminoacetylenes in modest to good yield.296 Vinyl Ti(iv) species prepared by the alkylation of vinylcarbene complexes with BTCl react with aldehydes to give allylic alcohols. Reaction with terminal alkynes produces conjugated dienes, in which a vinyl group regioselectively bonds to the unsubstituted side of carbon-carbon triple bond.297... [Pg.376]

Allyltributyltin, 10 Vinyltrimethylsilane, 343 Homoallylic ethers Allyltrimethylsilane, 11 Crotyltrimethylsilane, 86 Trityl perchlorate, 339 Homopropargylic alcohols Allenylboronic acid, 36 D imethoxy [ 1 -trimethylsilyl-1,2-buta-dienyljborane, 218 Lithium acetylide, 44 Triisopropoxy[l-(trimethylsilyl)-l,2-buta-dienyl]titanium, 218 Hydroperoxides Oxygen, singlet, 228 Hydroxy acids a-Hydroxy acids... [Pg.392]

Tetraamminelithium dihydrogenphosphide, 4590 Thorium dicarbide, 1023 Titanium carbide, 0558 Trimercury tetraphosphide, 4611 Tungsten carbide, 0560 Uranium carbide, 0559 Uranium dicarbide, 1024 Zinc phosphide, 4870 Zirconium dicarbide, 1025 METAL ACETYLIDES N-METAL DERIVATIVES METAL HYDRIDES METAL OXIDES METAL SULFIDES NITRIDES... [Pg.2438]

Compounds Bis-dimethylstibinyl oxide Bis(dimethylthallium) acetylide Butyllithium Nonacarbonyldiiron Octacarbonyldicobalt Pentacarbonyliron Tetracarbonylnickel Dibismuth trisulphide Dicaesium selenide Dicerium trisulphide Digold trisulphide Europium (II) sulphide Germanium (II) sulphide Iron disulphide Iron (II) sulphide Manganese (II) sulphide Mercury (II) sulphide Molybdenum (IV) sulphide Potassium sulphide Rhenium (VII) sulphide Silver sulphide Sodium disulphide Sodium polysulphide Sodium sulphide Tin (11) sulphide Tin (IV) sulphide Titanium (IV) sulphide Uranium (IV) sulphide ... [Pg.145]

SAFETY PROFILE A highly corrosive irritant to the eyes, skin, and mucous membranes. Mildly toxic by inhalation, Explosive reaction with alcohols + hydrogen cyanide, potassium permanganate, sodium (with aqueous HCl), tetraselenium tetranitride. Ignition on contact with aluminum-titanium alloys (with HCl vapor), fluorine, hexa-lithium disilicide, metal acetylides or carbides (e.g., cesium acetylide, rubidium ace-tylide). Violent reaction with 1,1-difluoro-ethylene. Vigorous reaction with aluminum, chlorine + dinitroanilines (evolves gas). Potentially dangerous reaction with sulfuric acid releases HCl gas. Adsorption of the acid onto silicon dioxide is exothermic. See also HYDROGEN CHLORIDE (AEROSOL) and HYDROCHLORIC ACID. [Pg.743]

Ignition on contact with bromine pentafluoride (or violent reaction), chlorine trifluoride, fluorine, metals (powdered) + water, aluminum-titanium alloys + heat, metal acetylides (e.g., cesium acetylide, copper(I) acetylide, lithium acetylide, mbidium acetylide), nonmetals (e.g., boron ignites at 700°C), phosphoms, sodium phosphinate. Violent reaction with acetaldehyde, aluminum + diethyl ether, dipropylmercury, titanium (above 113°C). Incandescent reaction with cesium oxide... [Pg.771]

A DFT calculation has been performed on the oligomerization of the acetylide titanium complex (OH)3Ti-C=C-Ti(OH)3 to the cyclopolyene titanacyclobutadiene [Ti(OH)3C]4 and titanacyclobenzene [Ti(OH)3C]6 species (Scheme 13), as simple models of hypothetical molecular metal carbides.52... [Pg.329]

Cyclic acetylide titanium complexes containing the 0-bis(ethynyl)tolane ligand have been synthesized, characterized, and used to prepare a heterobimetallic derivative with an Ni atom coordinated to three alkyne functionalities (Scheme 501).1286... [Pg.545]

A heterobimetallic Ti-Ni complex has been synthesized and characterized where the Ni atom is coordinated to three alkyne functionalities of a bis-Cp acetylide titanium fragment containing the <9-bis(ethynyl)tolane ligand (Scheme 731 ).1286... [Pg.643]

Bis-Cp acetylide titanium complexes have drawn considerable attention in regard to their third-order non-linear optical properties.2002... [Pg.662]

See other pages where Titanium acetylides is mentioned: [Pg.77]    [Pg.611]    [Pg.539]    [Pg.194]    [Pg.211]    [Pg.46]    [Pg.309]    [Pg.1246]    [Pg.1274]    [Pg.179]    [Pg.210]    [Pg.46]    [Pg.257]    [Pg.261]    [Pg.304]    [Pg.545]    [Pg.557]    [Pg.579]    [Pg.642]    [Pg.515]    [Pg.155]    [Pg.21]    [Pg.25]    [Pg.216]    [Pg.245]    [Pg.371]    [Pg.555]    [Pg.559]    [Pg.587]    [Pg.630]    [Pg.631]    [Pg.632]    [Pg.751]    [Pg.883]    [Pg.940]    [Pg.1008]    [Pg.1048]   


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