Diisopropyl-l,4,7-triazacyclononane

Solutions of HBr/CH3C02H are available commercially (e.g., Acros Organics, 711 Forbes Avenue, Pittsburgh, PA 15219 800-227-6701) in concentrations ranging from 30 to 33%. 

While extended reaction times (up to three days) have not been found to be detrimental, it is critical that the temperature of the reaction be maintained at 120°C. Above 130°C, N-dealkylation of the macrocyclic ring accompanies hydrolysis of the tosylamide group, yielding a nearly intractable mixture of mono- and dialkylated ligands. 

JV-(2-HYDROXYETHYL)-3,5-DIMETHYLPYRAZOLE, A DINUCLEAR COPPER COMPLEX, AND N-(2-p-TOLUENESULFONYLETHYL)-3,5-DIMETHYLPYRAZOLE 

Submitted by ELISABETH BOUWMAN and WILLEM L. DRIESSEN Checked by JEEHEE KANG and MARCETTA Y. DARENSBOURG1 

The present paper describes the synthesis of N-(2-hydroxyethyl)-3,5-dimethylpyrazole and the synthesis of the tosylated compound N-(2-p-tol-uenesulfonylethyl)-3,5-dimethylpyrazole which can be used for the synthesis of larger chelating ligands. The tosylation is carried out in a water/acetone mixture, unlike most classical tosylations, which are performed in pyridine.7 A high yield of pure tosylated product is obtained from this reaction. A water/acetone mixture as the solvent for the synthesis of other tosylates may very well be also successful. Since the compound N-(2-hydroxyethyl)-3,5-dimethylpyrazole may itself act as a didentate N,0 ligand in coordination compounds with transition metal ions,9 an example using Cu(II) is provided below. 

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Yb) to [Me2Si(tacn)CsMe4]K (tacn = l,4-diisopropyl-l,4,7-triazacyclononane) in THF yields monomeric solvent-free... 

Giesbrecht, G.R., Cui, C.M., Shafir, A. etal. (2002) Divalent lanthanide metal complexes of atriazacyclonoane-functionalized tetramethylcyclopentadienyl ligand X-ray crystal structures of [C5Me4SiMe2( Pr2-tacn)]Lnl (Ln=Sm, Yb tacn=l,4-diisopropyl-l,4,7-triazacyclononane). Organometallics, 21, 3841. 

The synthesis and characterization of divalent lanthanide complexes of a triazacyclononane-functionalized tetramethylcyclopentadienyl ligand have been reported.200 201 Addition of LnI2(THF)2 (Ln = Sm, Yb) to K[CsMe4SiMe2(Pr 2-tacn)] (Pr 2-tacn = l,4-diisopropyl-l,4,7-triazacyclononane) in THF yielded the monomeric organolanthanide [CsMe4SiMe2(Pr 2-tacn)]SmI (dark red crystals, 85% yield) and [C5Me4SiMe2(Pr 2-tacn)]YbI (red blocks, 80% yield) (Scheme 40). The crystal structures of both compounds have been explored.200... 

Reaction of [Cp 2Yb(/r-I)(THF)2]2 with K[N(SiMe3)2] generates Cp Yb[N(SiMe3)2] (THF)2 that crystallizes from toluene with a distorted piano stool (see Piano Stool Structure) geometry and addition of LnU (THF)2 (Ln = Sm, Yb) to [Me2Si(tacn)CsMe4]K (tacn = l,4-diisopropyl-l,4,7-triazacyclononane) in THF yields monomeric solvent-free... 

Reductive aminations of ortho- and r to-(diphenylphosphino)benzaldehydes with N,N -bis(2-pyridyl-2-ethyl)-amine (bpea) or l,4-diisopropyl-l,4,7-triazacyclononane (tacn ) afforded four novel ditopic NsP-donor ligands each... 

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