833-43-2Relevant academic research and scientific papers
Scandium(III) trifluoromethanesulfonate catalyzed aromatic nitration with inorganic nitrates and acetic anhydride
Kawada, Atsushi,Takeda, Shigemitsu,Yamashita, Kazumi,Abe, Hitoshi,Harayama, Takashi
, p. 1060 - 1065 (2007/10/03)
The rare earth metal(III) trifluoromethanesulfonate (rare earth metal(III) triflate, RE(OTf)3) was found to be an efficient catalyst for aromatic nitration with carboxylic anhydride-inorganic nitrate as the nitrating agent. In the presence of a catalytic amount of RE(OTf)3, the nitration of substituted benzenes proceeded to afford the corresponding nitrobenzenes. Especially, scandium(III) trifluoromethanesulfonate (scandium(III) triflate, Sc(OTf)3) is the most active catalyst among our tested Lewis acids. It was also found that acetic anhydride-Al(NO 3) · 9H2O is the most active nitrating agent in this system.
Potent, elective human beta3 adrenergic receptor agonists containing a substituted indoline-5-sulfonamide pharmacophore.
Mathvink,Barritta,Candelore,Cascieri,Deng,Tota,Strader,Wyvratt,Fisher,Weber
, p. 1869 - 1874 (2007/10/03)
A series of compounds possessing an N-substituted indoline-5-sulfonamide pharmacophore was prepared and evaluated for their human beta3 adrenergic receptor agonist activity. The SAR of a wide range of urea and heterocyclic substituents is discussed. 4-Octyl thiazole compound 8c was the most potent and selective compound in the series, with 2800-fold selectivity over beta1 binding and 1400-fold selectivity over beta2 binding.
Synthesis of terphenylboronic acid derivatives and recognition of anomers of 2-deoxyribofuranoside
Yamashita, Hiroshi,Amano, Koji,Shimada, Satoru,Narasaka, Koichi
, p. 537 - 538 (2007/10/03)
A terphenylboronic acid 1 and its silylated derivative 2 are prepared from (2-nitrophenyl)acetic acid for the purpose of controlling stereochemistry of synthetic organic reactions. These boronic acids are found to recognize α and β-anomers of 2-deoxyribofuranosides. That is, when these boron compounds are added to a 1 : 1 mixture of α and β-t-butyl 5-O-benzyl-2-deoxy-D-ribofuranosides, the boronic acids 1 and 2 form the corresponding boronates preferentially with the β-anomer.
Nucleotide. XIV. Substituierte β-Phenylaethyl-Gruppen. Neue Schutzgruppen fuer Oligonucleotid-Synthesen nach dem Phosphorsaeuretriester-Verfahren
Uhlmann, Eugen,Pfleiderer, Wolfgang
, p. 1688 - 1703 (2007/10/02)
Various o- and p-substituted β-phenylethanols (2-10) have been synthesized and investigated as blocking groups in the phosphotriester approach.A large number of 5'-O-tritylated thymidine-3'-phosphotriesters (13-36) with two different phosphate protecting groups have been prepared, characterized, and studied according to their chemical stability and usefullness for oligonucleotide syntheses.The combination of a 5'-O-monomethoxytrityl- and a 3'-(2,5-dichlorophenyl, p-nitrophenylethyl)-phosphate function as in 18 turned out to possess optimal properties as a monomeric nucleotide building block due to the fact that these blocking groups can be quantitatively and selectively be removed without harming each other by trifluoroacetic acid in chloroform to 41, by oximate to 42, and by DBU to 43.The base-catalyzed removal of the monosubstituted phenylethyl groups by DBU or DBN respectively as well as the disubstituted phenylethyl groups by triethylamine in aprotic solvents is a β-elimination process leading to phosphodiesters without attack on the P-center.
