Tetramethyl ethylene diamine TMEDA

The viscometric findings of Young 1211 who investigated the effect of tetramethyl ethylene diamine (TMEDA) addition on the viscosity of butadiene capped lithium polystyryl solutions showed that the results did not agree with those expected on the basis of the reaction... 

Polyamine complexes of organolithlum compounds have been extensively studied (8). Recent work by Fontanllle et al (24) has shown that also in these systems two isomeric ion pair complexes can be formed. The spectrophotometrlc "ion pair probe" used was 9-propylfluorenylllthlum (PFl ,Li+), which was complexed with tetramethyl ethylene diamine (TMEDA), hexamethyl triethylene tetramlne (HMTT) and tetramethyl tetraaza cydotet-radecane... 

Nishimura and coworkers 29f> 297 described a novel method for the enzymatic synthesis of oligosaccharide derivatives employing an a-chymotrypsin sensitive linker. The synthesis of the water soluble GlcNAc-polymer 197, sensitive to a-chymotrypsin, is shown in Fig. 18-27. Oxazoline derivative 193 was coupled with 6-(N-benzyloxycarbonyl-L-phenylalanyl)-amino-hexanol-l (194) followed by N-depro-tection of the phenylalanine and subsequent condensation with 6-acrylamido caproic acid 195. De-O-acetylation gave the polymerizable GlcNAc derivative 196. Finally, copolymerization of acrylamide and monomer 196 in the presence of ammoniumper-sulphate (APS) and N,N,N, N -tetramethyl ethylene diamine (TMEDA) gave the... 

The methylenetriimido sulfite dianion [CH2S(NtBu)3]2 is prepared by the treatment of [CH3S(NtBu)3] with methyllithium in the presence of TMEDA (A,A,A, A -tetramethyl ethylene diamine).177 The structure of [(TMEDA)2 Li2 H2CS(NtBu)3 ] (63) resembles that of 61 with the TMEDA ligands replacing the two THF ligands on each Li centre. 

The unique feature about anionic polymerization of diene to produce homopolymer was that the microstructure of the homopolymer could be altered and changed at will to produce unique physical and chemical properties. These microstructural changes can be introduced before, after or during the polymerization. For example, chelating diamines, such as tetramethyl ethylene and diamine (TMEDA) (18), with the alkyl-lithium catalyst have been used to produce polymer with 80 1,2 addition products, while the use of dipiperidine ethane (DPE),with same catalyst has produced polybutadiene with 100 1,2 addition product. 

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