Copper boron halides

Lithium dialkylcuprates-Boron trifluoride etherate, 208 Lithium diallylcuprate, 11 Lithium dibutylcuprate, 61, 208, 344 Lithium dibutylcuprate-Boron trifluoride etherate, 208 Lithium dimethylcuprate, 63, 151, 258 Lithium dimethylcuprate-Boron trifluoride etherate, 208 Organocopper reagents, 11, 61, 63, 131, 151, 207, 344 Organocopper reagents-Boron trifluoride etherate, 208 Organolithium reagents-Copper(I) halides, 58... 

Imines may be activated by complexation with Lewis acids, but this also increases the acidity of a-hydrogen atoms. A combination of copper(i) halide and boron trifluoride etherate is a possible solution to the problem [6, 7]. Activation by trimethylsilyl triflate is also effective with aldimines (though not with ketimines) [7, 8]. 

Diboron Tetrachloride. Tetrachlorodiborane(4) boron chloride. BX), mol wt 163,41, B 13,24%, Cl 86.16%, Prepd by passing gaseous boron trichloride through flow discharge between mercury or copper electrodes Urry cl al, J. Am. Client. Soc. 76, 5293 (1954) Wartik er al, If.org. Syn. 10, 118 (1967) hy passing boron trichloride vapor over boron monoxide at 200 McCloskey et aL, J, Am. Chem Soc. 93, 4750 (1961). Infrared and Raman spectra Linev-sky el al, J. Am Chem. Soc. 7S, 3287 (1953). Review of boron halides Massey, Advan. Inorg. Chem Radiockem 10, 1-152 (1967). 

In methylthiourea complexes with metals such as platinum, palladium, copper, zinc, and cadmium the amide band appears in a range from 1565 to 1580 cm S which is shifted from its normal position at 1550 cm in methylthiourea In thiourea complexes of platinum, palladium, zinc, and nickel the band appears between 1625 and 1615 cm compared to 1610 cm in thiourea [ ]. In boron halide complexes of acetamides the band appears in the 1555-1525 cm range [ ]. In trifluoroacetamides the band appears in almost the same positions as in the corresponding acetamides, near 1580 cm ... 

The most commonly used traditional Lewis acids are halides of aluminum, boron, titanium, zinc, tin, and copper. However, there are also more complex Lewis-acids that are quite effective catalysts that can be easily modified for carring out enantioselective processes, by incorporating chiral ligands. These can overcome some limitations associated with the use of classical Lewis acids [47]. 

The Suzuki coupling of aryl halides was also extended to tosylates recently. Benzothiazole 5-tosylate reacted with m-xylene-2-boronic acid (6.13.) to give the coupled product in 94% yield using palladium acetate and a stericly congested biphenyl based phosphine ligand as catalyst.17 Another class of less commonly utilised cross-coupling partners are methyltio derivatives. In the presence of a copper salt, which activates the carbon-sulphur bond, 2-methyltio-benzotiazol coupled readily with a series of arylboronic acids.18... 

Zinc—bromine storage batteries (qv) are under development as load-leveling devices in electric utilities (64). Photovoltaic batteries have been made of selenium or boron doped with bromine. Graphite fibers and certain polymers can be made electrically conductive by being doped with bromine. Bromine is used in quartz—halide light bulbs. Bromine is used to etch aluminum, copper, and semi-conductors. Bromine and its salts are known to recover gold and other precious metals from their ores. Bromine can be used to desulfurize fine coal (see Coal conversion processes). Table 5 shows estimates of the primary uses of bromine. 

The reaction of heterocyclic lithium derivatives with organic halides to form a C-C bond has been discussed in Section 3.3.3.8.2. This cannot, however, be extended to aryl, alkenyl or heteroaryl halides in which the halogen is attached to an sp2 carbon. Such cross-coupling can be successfully achieved by nickel or palladium-catalyzed reaction of the unsaturated organohalide with a suitable heterocyclic metal derivative. The metal is usually zinc, magnesium, boron or tin occasionally lithium, mercury, copper, and silicon derivatives of thiophene have also found application in such reactions. In addition to this type, the Pd-catalyzed reaction of halogenated heterocycles with suitable alkenes and alkynes, usually referred to as the Heck reaction, is also discussed in this section. 

The resulting triazoles can be N-alkylated by treatment with alkyl halides (0.25 mol/L, 30 equiv., DMF, NaOH), but mixtures of the 1-alkylated and 2-alkylated triazoles are obtained [255]. 1,2,4-Triazoles have also been prepared from N-amino-amidines (amidohydrazones Entry 4, Table 15.20), which were prepared from resin-bound thioamides by S-alkylation with methyl triflate followed by treatment with hydrazine [256]. 1,2,4-Tri azoles undergo Michael addition to polystyrene-bound a-acetamido acrylates to yield triazole-derived a-amino acids (Entry 7, Table 15.20). Benzotriazoles have been N-arylated on insoluble supports by treatment with aryl-boronic acids in the presence of catalytic amounts of copper salts (Entry 8, Table... 

Boron-sulfur bonds, addition, to alkynes, 10, 778 Boron trihalides, in boron compound synthesis, 9, 146 Boron-zinc exchange and copper-catalyzed substitutions, 9, 518 for organozinc halide preparation, 9, 89 Borostannylation, enynes, 10, 334... 

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