87614-63-9Relevant academic research and scientific papers
Imidazolium-based frameworks: Imidazolium salt-oxazoline/palladium(II) acetate in situ catalyst systems
Alcalde, Ermitas,Dinares, Immaculada,Mesquida, Neus,Rodriguez, Sandra
, p. 865 - 872 (2008/01/06)
New simple imidazolium-based bidentate ligand precursors were prepared by a three-step protocol and bis(oxazoline) ligands were prepared in two steps. A Suzuki-Miyaura reaction was utilized to ascertain the activity of a palladium(II) catalyst system gene
Coordination features of bis(N-heterocyclic carbenes) and bis(oxazolines) with 1,3-alkylidene-2,4,6-trimethylbenzene spacers. Synthesis of the ligands and silver and palladium complexes
Alcalde, Ermitas,Ceder, Rosa M.,Lopez, Cristina,Mesquida, Neus,Muller, Guillermo,Rodriguez, Sandra
, p. 2696 - 2706 (2008/03/14)
The synthesis of simple imidazolium-based ligand precursors containing a 1,3-alkylidene-2,4,6-trimethylbenzene spacer was examined and different synthetic protocols were applied depending on the nature of the alkylidene arm. For a methylene arm, simple dications 5a,b·2Cl were obtained directly. The higher homologue counterparts were conveniently prepared by general multistep routes following a five-step sequence for ethylene dications 6a,b·2Br or a six-step sequence for propylene dications 7a,b·2Br in ≥ 52% overall yield. Imidazolium salts based on the shorter methylene spacer were used to prepare palladium complexes (17-20) with N-heterocyclic carbenes via transmetallation from well-defined silver compounds or directly in basic conditions. In order to facilitate spectroscopic characterisation of the palladium species two [Pd(allyl)(bis-oxazoline)]+ (25-26) complexes with the same ligand bridge were synthesized. [PdX2bisL] complexes appeared in solution as mixtures of species, mononuclear with cis- or trans-geometry or oligomeric compounds. The reaction of [PdCl(allyl)] 2 and -bis(carbene)(AgX)2 complexes in 1: 1 or in 0.5: 1 ratio leads to binuclear compounds [Pd2Cl2(allyl) 2(-bis-carbene)] (19a,19b) and to very labile monomeric [Pd(allyl)(bis-carbene)]+ (20a,20b) compounds, respectively. The preparation of analogous [Pd(allyl)(bis-oxazoline)]+ complexes showed the formation of one of the four possible isomers. [Pd(allyl)(bis-oxazoline)] PF6 complexes were inactive as catalytic precursors in the allylic substitution reaction. The Royal Society of Chemistry.
Phenol-containing bis(oxazolines): synthesis and fluorescence sensing of amines
Chung, Yun Mi,Raman, Balamurali,Ahn, Kyo Han
, p. 11645 - 11651 (2007/10/03)
The fluorescence sensing of primary amines as their neutral forms has been studied with bis(oxazolinyl)phenols (Me-BOP, Ph-BOP), which are efficiently synthesized starting from mesitylene in six steps and in overall 12-22% yields. The BOP sensors showed f
Endothelin antagonists: Substituted mesitylcarboxamides with high potency and selectivity for ET(A) receptors
Wu, Chengde,Decker, E. Radford,Blok, Natalie,Bui, Huong,Chen, Qi,Raju,Bourgoyne, Andree R.,Knowles, Vippra,Biediger, Ronald J.,Market, Robert V.,Lin, Shuqun,Dupré, Brian,Kogan, Timothy P.,Holland, George W.,Brock, Tommy A.,Dixon, Richard A. F.
, p. 4485 - 4499 (2007/10/03)
We have previously disclosed the discovery of 2,4-disubstituted anilinothiophenesulfonamides with potent ET(A)-selective endothelin receptor antagonism and the subsequent identification of sitaxsentan (TBC11251, 1) as a clinical development compound (Wu et al. J. Med. Chem. 1997, 40, 1682 and 1690). The orally active 1 has demonstrated efficacy in a phase II clinical trial of congestive heart failure (Givertz et al. Circulation 1998, 98, Abstr. 3044) and was active in rat models of myocardial infarction (Podesser et al. Circulation 1998, 98, Abstr. 2896) and acute hypoxia-induced pulmonary hypertension (Chen et al. FASEB J. 1996, 10 (3), A104). We now report that an additional substituent at the 6-position of the anilino ring further increases the potency of this series of compounds. It was also found that a wide range of functionalities at the 3-position of the 2,4,6-trisubstituted ring increased ETA selectivity by ~10-fold while maintaining in vitro potency, therefore rendering the compounds amenable to fine-tuning of pharmacological and toxicological profiles with enhanced selectivity. The optimal compound in this series was found to be TBC2576 (7u), which has ~10- fold higher ETA binding affinity than 1, high ET(A)/ET(B) selectivity, and a serum half-life of 7.3 h in rats, as well as in vivo activity.
