583-61-9Relevant articles and documents
Generation and reactions of pyridyllithiums via Br/li exchange reactions using continuous flow microreactor systems
Nagaki, Aiichiro,Yamada, Daisuke,Yamada, Shigeyuki,Doi, Masatomo,Ichinari, Daisuke,Tomida, Yutaka,Takabayashi, Naofumi,Yoshida, Jun-Ichi
, p. 199 - 207 (2013/03/28)
A continuous flow microreactor method for generating and carrying out reactions on pyridyllithiums has been developed based on Br/Li exchange reactions of bromopyridines and dibromopyridines. The reactions can be carried out without using cryogenic conditions by virtue of short residence times and efficient heat transfer, while very low temperatures such as-78 or-110°C are required for conventional batch macro methods. Moreover, sequential introduction of two different electrophiles has been successfully achieved using dibromopyridines in an integrated flow microreactor system composed of four micromixers and four microtube reactors.
Nucleophilic addition to 3-substituted pyridinium salts: Expedient syntheses of (-)-L-733,061 and (-)-CP-99,994
Lemire, Alexandre,Grenon, Michel,Pourashraf, Mehrnaz,Charette, Andre B.
, p. 3517 - 3520 (2007/10/03)
(Chemical Equation Presented) The addition of nucleophiles to 3-substituted pyridinium salts prepared from N-methylbenzamide and various pyridines has been investigated. Good to excellent regioselectivities favoring the 2,3-disubstituted 1,2-dihydropyridines were observed. The resulting 1,2-dihydropyridines led to the corresponding 2,3-disubstituted pyridines upon treatment with Mn(OAc)3/NaIO4. This methodology was also successfully applied to the enantioselective syntheses of (-)-L-733,061 and (-)-CP-99,994, two members of a new class of highly potent, nonpeptide, Substance P antagonists.
Titanocene(III) catalyzed homogeneous hydrosilation-hydrogenation of pyridines
Harrod,Shu,Woo,Samuel
, p. 1075 - 1085 (2007/10/03)
The homogeneous catalytic hydrosilation-hydrogenation of pyridines is observed in the presence of Cp2TiMe2 (Cp = η5-C5H5) and CpCp*TiMe2 (Cp* = η5-C5Me5) as catalysts and using PhSiH3 or PhMeSiH2 as the source of Si-H. Under appropriate conditions, and with appropriate ring-substitution, good yields of the N-silyldihydropyridine or N-silyltetrahydropyridine products are be obtained. Although complete saturation is not achieved with organosilane alone, carrying out the reaction under moderate H2 pressures can give excellent yields of N-silylpiperidines. Under moderate pressures of H2, [Cp2TiH]2 catalyzes rapid H-D exchange between H2 and the 2- and 6-positions of C5D5N. Under the same conditions, only traces of hydrogenation are observed. This, together with the regioselectivity of 3-picoline hydrosilation-hydrogenation, leads to the conclusion that the key step in the reaction is probably addition of Ti-Si to C=N.