Pentamethyl diethylenetriamine

Other monomeric silylamido complexes have also been obtained by the addition of tmeda (A, A, A A"-tetramethylethylenediamine) or pmdeta (N,N,N ,N" - pentamethyl-diethylenetriamine) to afford [(tmeda)LiN(SiMe3)2] which has three coordinate lithium Li—N(amide)= 1.893(3) A and [(pmdeta)LiN(SiMe3)2 with 4-coordinate Li and Li—N (amide = 1.988(6) A. The use of very large substituents at the amido ligand can also afford monomeric structures. Examples include [Li(thf)3N(SiMe2Ph)2], [Li(thf)2N(SiPh3)2l/ [Li(th )2N(SiBu 2F)2] [Li(thf)2N (C6F5)(SiBu 2F) ] and [Li(thf)3 NMes (SiPr 2X) ]... 

It must be noted tliat, even with an extremely hydrophobic catalyst, catalyst-free particles would be formed by radical exit and nucleation of new particles, and thus uncontrolled polymerization would occur. On the other hand, it is also proposed that with more hydrophilic ligands (such as Meg-TREN, or pentamethyl diethylenetriamine (PMDETA) [221]) all the catalyst is located in the aqueous phase, and uncontrolled polymerization occurs in the hydrophobic polymer particles. However, these ligands are also ineffective in controlling the aqueous polymerization of water-soluble monomers (see above), hinting that ligand dissociation might also occur in these systems [215]. 

Homogenous atom-transfer radical polymerization of methyl methacrylate under microwave irradiation conditions has also been studied by Zhu et al. [23, 24]. In a typical run, a small amount of CuCl, N,N,N, N",N"-pentamethyl-diethylenetriamine, with ethyl 2-bromobutyrate as activator-initiator system, were placed in a 10-mL glass tube with 1 mL DMF and 5 mL methyl methacrylate. The tube was sealed and placed in a two-necked reaction flask filled with hexane, so that temperature was controlled by the boiling point of the solvent during reflux in a modified domestic microwave oven. Linear first-order rate plots, linear in-... 

Lithiation and 3-lithiation of IV-substituted indoles may be readily achieved. Indoles bearing IV-directed metallation groups may be lithiated at the 2- or the 7-positions. A special case is N-(2,2-diethylbutanoyl) indole (31), which undergoes lithiation as a function of the additive used in combination with i-BuLi. As indicated in eq 49, the use of the 5-BuLi-TMEDA combination leads to 7-lithiation. On the contrary, 2-lithiation occurs in the presence of t-BuOK, and 3-lithiation results using PMDTA (MA,lV, A(",A("-pentamethyl-diethylenetriamine). Quenching with various electrophiles leads to the formation of 2-, 3-, or 7-substituted indoles 32,33, or 34 in moderate to excellent yields. ... 

A series of complexes of the type ML(SCN) (C104)2-, (M - Zn, Cd, or Hg x = 1 or 2) has been prepared where L is en and its tetramethyl derivative, diethylenetriamine and its pentamethyl derivative, triethylenetetramine and its hexamethyl derivative, and bis(ethylenediamine). The complexes are either monomeric with four-, five- or six-coordinate metal, or polymeric containing bridging thiocyanate the perchlorate is always ionic. The thiocyanate is generally bonded through nitrogen to zinc and cadmium (and through sulfur to mercury).181... 

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