Tetramethylethylenediamine TMED

N, N, N, N -Tetramethylethylenediamine, tmed U (CF3)2CHO 4-tmed Diaminoalkanes ThBr4 xL H20... 

Diphenylacetylene has been used as a starting point for the generation of metalloindenes of Si (294), Sn (294), and As (45). Reaction of BuLi-tetramethylethylenediamine (TMED) with diphenylacetylene results in addition metallation to produce a dilithio organometallic that will react with a metal dihalide derivative ... 

Effects of nonether solvent on the equilibrium between monomeric complexes have received little attention. An H-NMR investigation of the effect of N,N,N, N -tetramethylethylenediamine (TMED) on THE solutions of ethylmagnesium bromide demonstrated little effect on the equilibrium constant at — [32] however, TMED... 

A side reaction may be metallation of hydrogens in positions ortho or a to the halogen. The fast rates of halogen-Li exchanges, especially in cold electron-donating solvents, enable low T to be used and the extent of the slower metallations to be minimized. The presence of tetramethylethylenediamine (TMED) however, can promote metallations more than metal-hydrogen exchanges . 

P Sequential treatment with KH then n-C H,Li and tetramethylethylenediamine (TMED) s Mixed Li. K dianion 9-Carbomethoxyfluorene,... 

Solid silylmetallic reagents can be isolated. Evaporation of liq NHj siffords solid reagents, such as Et3GeK pure, solid MejSiLi is prepared by vacuum sublimation and (MejSOjSiLi S THF (tetrahydrofuran) may be recrystallized from pentane and Li(SiPh2)4Li 2 THF from cyclohexane. Crystalline 1 1 adducts, e.g., EtjSiLi-L, are formed by addition of hexamethylphosphoramide (HMPA), tetramethylethylenediamine (TMED), or 1,2-dimethoxyethane (DME) to Et3SiLi in hexane. Solid McjSiLi DME is also known . Isolation of KSiHj, free of solvent and KH is also possible . 

The electrochemical oxidation of Cd in the presence of PhjSnCl in CHjCN-benzene and in the presence of tetramethylethylenediamine (TMED) and bipy yields the corresponding adducts PhjSnCdCTTMED (in 30% yield), and PhjSnCdCl-bipy (in 43 % yield), respectively ... 

The reaction of EtjSnH with EtjZn results in decomposition with the formation of Zn metal, ethane, tetraethyltin, hexaethylditin and a polymerp The reaction of PhjSnH with EtjZn in pentane or benzene forms metallic Zn. However, when hydrostannolysis is carried out with preformed complexes of Et2Zn or with a complexing solvent, such as 1,2-dimethoxyethane (DME) or tetrahydrofuran (THE), or by using a preformed coordination complex of EtjZn with tetramethylethylenediamine (TMED) or bipy, the bis(triphenyltin)zinc complexes are obtained in high yields under mild conditions (—20° to 0°C)2 ... 

For moderately hindered olefins, the redistribution equilibria may be favorable to the monoalkylborane, e.g., for a-pinene . The equilibrium is reached after 120 h at 25°C and the mixture is composed of monoisopinocampheylborane (IpcBH2, 91%), BH3 (4.5 %) and diisopinocampheylborane (IPC2BH, 4.5 %). The small amount of BH3 can be removed by pumping off the solvent and addition of pentane, followed by an equivalent amount of tetramethylethylenediamine (TMED). The TMED-BH3 complex precipitates and can be filtered. By further addition of the amine, the TMED-2 IpcBH2 complex is formed as a white solid. 

When (Me3Si)3Al is treated with tetramethylethylenediamine (TMED), [(Me3Si)3Al]2 TMED is isolated. ... 

Dilithium-thioacrolein dianion with 2 equiv tetramethylethylenediamine (TMED). 

Dilithium derivatives of delocalized dianions of thioacrolein and Li2(CH2CRCHS) homologues, formed by metallation of the corresponding allylmercaptans in the presence of 2 equiv tetramethylethylenediamine (TMED) react with Br2Mg OEt2 in THE (0°C,... 

C leaving pure RCal. Corresponding 1 1 complexes are formed with dimeth-oxyethane (DME), diglyme, tetramethylethylenediamine (TMED) and diaza-(l,4)-bicyc-lo(2.2.2)octane. 

The complex ion [CuCHHIB) ] -, formed by the reaction of copper(ii) ions with hexafluorohydroxyisobutyric acid, is thought from its magnetic moment to have square-planar co-ordination. In the presence of ethylene-diamine (en) or tetramethylethylenediamine (tmed), amine salts [HaB] +[Cu(HHIB)2l (B = en or tmed) are formed a further product with ethylenediamine contains two diamine molecules per metal atom, and is thought to be the carboxylate complex H0-C(CF3)2 C02Cu(en)2 02C-QCF2)2(0H). ... 

The n-butyl-lithium chelate complex with tetramethylethylenediamine (TMED) is a particularly powerful metalating agent... 

The lithium atom in hypothetical complexes RLiLs would be carrying too high a negative charge, and the molecule would be in conflict with the electroneutrality principle. The tetramethylethylenediamine (TMED) complexes of butyl-lithium and some other organolithium compounds have already been mentioned in connection with metalation reactions (p 49). The effect of forming two Li—N co-ordinate links is to make the carbon atom boimd to lithium very strongly nucleophilic. 

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