112193-79-0Relevant articles and documents
New synthetic routes for 1-benzyl-1,4,7,10-tetraazacyclododecane and 1,4,7,10-tetraazacyclododecane-1-acetic acid ethyl ester, important starting materials for metal-coded DOTA-based affinity tags
Kohl, Stephan W.,Kuse, Katharina,Hummert, Markus,Schumann, Herbert,Mügge, Clemens,Janek, Katharina,Wei?hoff, Hardy
, p. 397 - 406 (2007)
Two improved routes to synthesize 1-benzyl-1,4,7,10-tetraazacyclododecane (6) and 1,4,7,10-tetraazacyclododecane-1-acetic acid ethyl ester (11) are described as well as the synthesis of 1-{2-[4-(maleimido-N-propylacetamidobutyl) amino]-2-oxoethyl}-1,4,7,10-tetraazacyclododecane-4,7,10-triacetic acid (17) and its Y, Ho, Tm, and Lu complexes. The 1H and 13C NMR spectra of the new compounds as well as the single crystal X-ray structure analyses of the intermediates 4-benzyl-1,7-bis(p-toluenesulfonyl) diethylenetriamine (3) and 1,4,7-tris(p-toluenesulfonyl)diethylenetriamine (7) are reported and discussed. The rare earth complexes of 17 have been characterized by 1H NMR spectroscopy and MALDI-TOF mass spectrometry.
Mild regiospecific synthesis of 1-alkoxy-isochromenes catalyzed by well-defined [silver(I)(pyridine-containing ligand)] complexes
Dellacqua, Monica,Castano, Brunilde,Cecchini, Clara,Pedrazzini, Tommaso,Pirovano, Valentina,Rossi, Elisabetta,Caselli, Alessandro,Abbiati, Giorgio
, p. 3494 - 3505 (2014/05/06)
The synthesis of 3-substituted-1-alkoxyisochromenes starting from 2-alkynylbenzaldehydes and different alcohols is reported. The reaction is catalyzed by a silver(I) complex with an original macrocyclic pyridine-containing ligand. The approach is characterized by absolute regioselectivity, mild reaction conditions, good to excellent reaction yields, cleanness of the reaction, and reduced purification steps. The reaction mechanism was investigated by in-depth 1H NMR experiments and an aimed trapping experiment.
Asymmetric cyclopropanation of olefins catalysed by Cu(i) complexes of chiral pyridine-containing macrocyclic ligands (Pc-L*)
Castano, Brunilde,Guidone, Stefano,Gallo, Emma,Ragaini, Fabio,Casati, Nicola,MacChi, Piero,Sisti, Massimo,Caselli, Alessandro
, p. 2451 - 2462 (2013/03/28)
The synthesis and characterisation of copper(i) complexes of chiral pyridine-containing macrocyclic ligands (Pc-L*) and their use as catalysts in asymmetric cyclopropanation reactions are reported. All ligands and metal complexes were fully characterised, including crystal structures of some species determined by X-ray diffraction on single crystals. This allowed characterising the very different conformations of the macrocycles which could be induced by different substituents or by metal complexation. The strategy adopted for the ligand synthesis is very flexible allowing several structural modifications. A small library of macrocyclic ligands possessing the same donor properties but with either C1 or C2 symmetry was synthesized. Cyclopropane products with both aromatic and aliphatic olefins were obtained in good yields and enantiomeric excesses up to 99%.
Sulfonamide-supported aluminum catalysts for the ring-opening polymerization of rac-lactide
Schwarz, Andrew D.,Chu, Zengyong,Mountford, Philip
experimental part, p. 1246 - 1260 (2010/05/01)
The synthesis, structures, and ring-opening polymerization (ROP) capability of a wide range of sulfonamide-supported aluminum alkyl and alkoxide complexes are reported. The synthesis of the new protio-ligands PhCH2N(CH 2CH2NHSO2R)2 (R = ToI (15, H 2N2TsNph) or Me (16, H 2N2MsNph)) is described. These and the previously reported 1,2-C6H10(NHSO2R) 2 (R = Tol (11, H2CyN2Ts) or Mes (12, H2CyN2so2Mes)) and RCH 2N(CH2CH2NHSO2TOl)2 (R = MeOCH2 (13, H2N2TSNOMe) or 2-NC5H4 (14, H2N2 TsNpy)) reacted with AlEt3 to form Al(CyN 2Ts)Et(THF) (17), Al(CyN2SO2Mes) Et(THF) (18), and Al(N2TsNR)Et (R = Ph (19), OMe (20), or py (21)), respectively. Subsequent reaction of these ethyl complexes with R'OH (R' = 1Pr or Bn) resulted in protonolysis of the sulfonamide supporting ligands to yield a mixture of products including Al(OR')3- In contrast, reaction of Al(OR')Et2 (R' = 1Pr, Bn, CH2CH2NH2, or CH2CH 2NMe2) with various protio-ligands formed the sulfonamide-supported alkoxides Al(N2TsN py)(OR') (R' = 1Pr (22) or Bn (23)), Al(N2 MsNph)(OR') (R' = Pr (26) or Bn (27)), Al(N 2TsNR)(OCH2CH2NH 2) (R = Ph (29), OMe (30), or py (31)), Al(CyN2 Ts)(OCH2CH2NMe2) (32), and Al(N 2TsNph)(OCH2CH2NMe 2) (33). Unexpectedly, reaction OfAl(OTr)Et2 with H 2N2TsNOMe led to O-demethylation of the sulfonamide ligand. Reaction of AlMe2Cl with H2N 2TsNph gave [Al(NTs 2Nph)Cl]2 (28). X-ray diffraction studies revealed four- or five-coordinate C.v-symmetric structures for 17-21, a five-coordinate C2-symmetric sulfonamide-bridged dimer for 28, and a five-coordinate C,-symmetric monomer for 30 stabilized by intramolecular hydrogen bonding between the sulfonyl oxygens and the amine protons. Compounds 19, 21, 22-27, and 29-33 are all catalysts for the ROP of rac-lactide, with the alkoxide compounds 22-27 and 32 giving well-defined molecular weights and molecular weight distributions. These compounds were also active in the melt at 130 °C, giving atactic poly(rac-lactide) with moderate to narrow PDIs and extremely good control of Mn and high activity in the case of 23.
