86802-68-8Relevant academic research and scientific papers
Sequential C-S and S-N Coupling Approach to Sulfonamides
Chen, Kai,Chen, Wei,Han, Bing,Chen, Wanzhi,Liu, Miaochang,Wu, Huayue
supporting information, p. 1841 - 1845 (2020/03/04)
A one-pot three-component reaction involving nitroarenes, (hetero)arylboronic acids, and potassium pyrosulfite leading to sulfonamides was described. A broad range of sulfonamides bearing different reactive functional groups were obtained in good to excellent yields through sequential C-S and S-N coupling that does not require metal catalysts.
Insights into functional-group-tolerant polymerization catalysis with phosphine-sulfonamide palladium (II) complexes
Jian, Zhongbao,Falivene, Laura,Wucher, Philipp,Roesle, Philipp,Caporaso, Lucia,Cavallo, Luigi,Gttker-Schnetmann, Inigo,Mecking, Stefan
supporting information, p. 2062 - 2075 (2015/03/05)
Two series of cationic palladium(II) methyl complexes {[(2-MeOC6H4)2PC6H4SO2NHC6H3(2,6-R1,R2)]PdMe}2[A]2 (X1+-A: R1=R2=H: H1+-A; R1 = R2 = CH(CH3)2: DIPP1+-A; R1 = H, R2 = CF3: CF31+-A; A = BF4 or SbF6) and neutral palladium(II) methyl complexes {[(2-MeOC6H4)2PC6H4SO2NC6H3(2,6-R1,R2)]PdMe(L)} (X1-acetone: L = acetone; X1-dmso: L = dimethyl sulfoxide; X1-pyr: L=pyridine) chelated by a phosphine-sulfonamide were synthesized and fully characterized. Stoichiometric insertion of methyl acrylate (MA) into all complexes revealed that a 2,1 regiochemistry dominates in the first insertion of MA. Subsequently, for the cationic complexes X1+-A, β-H elimination from the 2,1-insertion product X2+-AMA-2,1 is overwhelmingly favored over a second MA insertion to yield two major products X4+-AMA-1,2 and X5+-AMA. By contrast, for the weakly coordinated neutral complexes X1-acetone and X1-dmso, a second MA insertion of the 2,1-insertion product X2MA-2,1 is faster than β-H elimination and gives X3MA as major products. For the strongly coordinated neutral complexes X1-pyr, no second MA insertion and no β-H elimination (except for DIPP2-pyrMA-2,1) were observed for the 2,1-insertion product X2-pyrMA-2,1. The cationic complexes X1+-A exhibited high catalytic activities for ethylene dimerization, affording butenes (C4) with a high selectivity of up to 97.7% (1-butene: 99.3%). Differences in activities and selectivities suggest that the phosphine-sulfonamide ligands remain coordinated to the metal center in a bidentate fashion in the catalytically active species. By comparison, the neutral complexes X1-acetone, X1-dmso, and X1-pyr showed very low activity towards ethylene to give traces of oligomers. DFT analyses taking into account the two possible coordination modes (O or N) of the sulfonamide ligand for the cationic system CF31+ suggested that the experimentally observed high activity in ethylene dimerization is the result of a facile first ethylene insertion into the O-coordinated PdMe isomer and a subsequent favored β-H elimination from the N-coordinated isomer formed by isomerization of the insertion product. Steric hindrance by the N-aryl substituent in the neutral systems CF31 and H1 appears to contribute significantly to a higher barrier of insertion, which accounts for the experimentally observed low activity towards ethylene oligomerization.
Development of a scalable process for CI-1034, an endothelin antagonist
Jacks, Thomas E.,Belmont, Daniel T.,Briggs, Christopher A.,Horne, Nicole M.,Kanter, Gerald D.,Karrick, Greg L.,Krikke, James J.,McCabe, Richard J.,Mustakis, Jason G.,Nanninga, Thomas N.,Risedorph, Guy S.,Seamans, Ronald E.,Skeean, Richard,Winkle, Derick D.,Zennie, Thomas M.
, p. 201 - 212 (2013/09/04)
A concise, convergent multikilogram synthesis of CI-1034 (1), a potent endothelin receptor antagonist, is described. A 15-step preparation from commercially available o-vanillin and benzenesulfonyl chloride employs a remarkably robust Suzuki coupling between a boronic acid and an aromatic sulfonate ester as the key synthetic step. A scalable route capable of producing multikilogram quantities of CI-1034 with no chromatographic steps is described in this contribution. Improvements to the process included using a 4-fluorobenzenesulfonate ester as a suitable substitute for the triflate group in the Suzuki reaction and the use of MgCl2 as a substitute for TiCl4 in a Dieckmann condensation to provide the benzothiazine dioxide core.
Certain benzothiazine dioxide endothelin antagonists and processes for their preparation
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, (2008/06/13)
The instant invention is a series of benzothiazine dioxides, or a pharmaceutically acceptable salt thereof, which are potent endothelin A antagonists with profound in vitro activity, and improved syntheses for the Formula 1 The compounds are useful in treating elevated levels of endothelin, essential renovascular malignant and pulmonary hypertension, cerebral infarction, cerebral ischemia, congestive heart failure, and subarachnoid hemorrhage.
Preparation of Nonsymmetrical p-Benzoquinone Diimines for Evaluation as Protein Cleavage Reagents
Holmes, Thomas J.,Lawton, Richard G.
, p. 3146 - 3150 (2007/10/02)
In an effort to improve the yield, selectivity, and mildness of reaction conditions employed in protein cleavage with bisalkylating quinone diimines, a series of analogous reagents (1a-h) were prepared.These novel N1,N4 nonsymmetrica
