Titanium chloride-Zinc/copper couple

Titanium(IV) chloride-Titanium(IV) isopropoxide, 215 Titanium(IV) chloride-Zinc, 310 Titanium(III) chloride-Zinc/copper couple, 303... 

Tiglic acid, 421, 423 Tigloyl chloride, 365 Titanium(O), 481-482, 483 Titanium(lII) chloride, 482-483 Titanium(l 11) chloride-Zinc/copper couple, 483... 

Solutions of low-valence titanium chloride (titanium dichloride) are prepared in situ by reduction of solutions of titanium trichloride in tetrahydrofuran or 1,2-dimethoxyethane with lithium aluminum hydride [204, 205], with lithium or potassium [206], with magnesium [207, 208] or with a zinc-copper couple [209,210]. Such solutions effect hydrogenolysis of halogens [208], deoxygenation of epoxides [204] and reduction of aldehydes and ketones to alkenes [205,... 

Lithium butyldimethylzincate, 221 Lithium sec-butyldimethylzincate, 221 Organolithium reagents, 94 Organotitanium reagents, 213 Palladium(II) chloride, 234 Titanium(III) chloride-Diisobutylalu-minum hydride, 303 Tributyltin chloride, 315 Tributyl(trimethylsilyl)tin, 212 3-Trimethylsilyl-l, 2-butadiene, 305 Zinc-copper couple, 348 Intramolecular conjugate additions Alkylaluminum halides, 5 Potassium t-butoxide, 252 Tetrabutylammonium fluoride, 11 Titanium(IV) chloride, 304 Zirconium(IV) propoxide, 352 Miscellaneous reactions 2-(Phenylseleno)acrylonitrile, 244 9-(Phenylseleno)-9-borabicyclo[3.3.1]-nonane, 245 Quina alkaloids, 264 Tributyltin hydride, 316 Conjugate reduction (see Reduction reactions)... 

Diethylzinc-Titanium(IV) chloride, 21 Diiodomethane-Diethylzinc, 276 Diiodomethane-Zinc-copper couple, 275... 

Iriniethoxyborohydridc. Stannous bromide. Stannous chloride. Teltamethylammonium borohydride. Thioglycolic acid. Tin. Titanium tetrachloride. Tri-/-butylaluminum. Tri-n-butyltin hydride. Triethylene glycol (see Zinc). Triethyl phosphite. Trimethylamine borane. Trimethylammonium formate. Trimethylsilane (indirect). Triphenyltin hydride. Tris-(tripbenylphosphine)chlor(X hodium. Zinc. Zinc amalgam. Zinc-Copper couple. Zinc hydrosulfide. 

Alkenes can be obtained from aldehydes or ketones on reductive dimerization by treatment with a reagent prepared from titanium(III) chloride and zinc-copper couple (or L1A1H4), or with a species of active titanium metal formed by reduction of titanium(III) chloride with potassium or lithium metal. This McMurry coupling reaction is of wide application, but in intermolecular reactions generally affords a mixture of the E- and Z-alkenes (2.99). 

According to G. Pellagri,41 potassium chlorate inaq. soln. is reduced to the chloride by shaking it with iron filings and H. Eccles noted that it is readily reduced by boiling it with a copper-zinc couple—potassium perchlorate is not reduced under similar conditions. Hence, the amount of the one salt can be readily determined when in the presence of the other. On the other hand, J. G. Williams found the perchlorates are reduced by titanium trichloride, while the chlorates are not affected. Here again an analytical process is available. 

The inline conversion of nitrate to nitrite and subsequent spectrophotometric determination after diazotization and coupling reactions is the basis of an important set of analytical methods for the simultaneous determination of both ions. Either homogeneous (titanium(III) chloride, hydrazinium sulfate, etc.) or heterogeneous (zinc, cadmium, amalgamated cadmium, copperized cadmium, etc.) reduction agents, photochemical or enzymatic reactions have been used [157]. The nitrite so produced is determined through spectrophotometric detection of the reddish purple azo dye formed as a result of the modihed Griess chemistry. 

---