233770-01-9Relevant articles and documents
Insight into the Modes of Activation of Pyridinium and Bipyridinium Salts in Non-Covalent Organocatalysis
Weiss, Robin,Golisano, Tamara,Pale, Patrick,Mamane, Victor
supporting information, p. 4779 - 4788 (2021/09/06)
A series of pyridinium and bipyridinium salts were prepared and their catalytic properties were evaluated in the aza-Diels-Alder reaction between imines and Danishefsky diene. Depending on the substituents of the pyridinium/bipyridinium rings and on the nature of the counterion, two mechanisms of activation were demonstrated. In case of non-substituted rings, the substrate is activated through charge transfer involving the aryl ring on the C-side of the imine. When halogen atoms were introduced on the catalysts, the activation mode switched to halogen bond involving the imine nitrogen lone pair. Moreover, alternative activation modes based on hydrogen bonding and radical cation were ruled out. This work allowed us to develop two families of catalysts whose potential was demonstrated in the cycloaddition of various imines with Danishefsky diene. The first family is composed of the simple methyl pyridinium triflate and dioctyl bipyridinium triflate. The former is active only with imines bearing a p-methoxyphenyl group on the C-side and the latter was found to be efficient with imines bearing different substituents on both the N- and C-sides of the imines. The second family is based on halogenated pyridinium salts which proved active with almost all considered imines. (Figure presented.).
Homoleptic zincate-promoted room-temperature halogen-metal exchange of bromopyridines
Chau, Nguyet Trang Thanh,Meyer, Maxime,Komagawa, Shinsuke,Chevallier, Floris,Fort, Yves,Uchiyama, Masanobu,Mongin, Florence,Gros, Philippe C.
experimental part, p. 12425 - 12433 (2011/01/05)
Homoleptic lithium tri- and tetraalkyl zincates were reacted with a set of bromopyridines. Efficient and chemoselective bromine-metal exchanges were realized at room temperature with a substoichiometric amount of nBu 4ZnLi2·TMEDA reagent (1/3 equiv; TMEDA=N,N,N′,N′-tetramethylethylenediamine). This reactivity contrasted with that of tBu4ZnLi2·TMEDA, which was inefficient below one equivalent. DFT calculations allowed us to rationalize the formation of N...Li stabilized polypyridyl zincates in the reaction. The one-pot difunctionalization of dibromopyridines was also realized using the reagent stoichiometrically. The direct creation of C-Zn bonds in bromopyridines enabled us to perform efficient Negishi-type cross-couplings. Mild zincation! nBu4ZnLi2·TMEDA (in substoichiometric amounts) promoted efficient and chemoselective room-temperature bromine-metal exchange of a range of bromopyridines (see scheme). DFT calculations strongly supported the formation of a stabilized tripyridylzincate, which could be reacted with electrophiles or be directly involved in palladium-catalyzed cross-coupling reactions.
3-AMINOCYCLOPENTANECARBOXAMIDES AS MODULATORS OF CHEMOKINE RECEPTORS
-
Page/Page column 12; 27, (2008/06/13)
The present invention is directed to compounds of Formula I: which are modulators of chemokine receptors. The compounds of the invention, and compositions thereof, are useful in the treatment of diseases related to chemokine receptor expression and/or activity.
PYRIDYL DERIVATIVES AND THEIR USE AS MGLU5 RECEPTOR ANTAGONISTS
-
Page/Page column 35, (2008/06/13)
The present invention is directed toward pyridyl derivatives of formula (I) as antagonists of the mGlu5 receptor. As such the compounds may be useful for treatment or prevention of disorders remedied by antagonism of the mGlu5 receptor, wherein Ar is phenyl or napthyl each of which may be substituted by one or more C1-C4 alkyl, C1-C4 alkoxy, C1-C5 acyl, halo, amino, nitro, cyano, hydroxy, C1-C5 acylamino, C1-C4 alkylsulfonylamino, mono-, di- or trifluorinated C1-C3 alkyl, substituents which may be the same or different and may bear a CONH2, CONHCH3, CON(CH3)2, CO2H, CO2CH3, OCF3, CH2NHCOCH3, CH2NH2, CH2N(CH3)2, CH2CN, CH2OH, CH2NHSO2CH3, CH2N(CH3)(CH2)2 CN, CH2N(CH3)CH(CH3)2, CH2NHCH(CH3)2, CH2NH(CH2)2CH3, CH2NHCO2R4, CH2NHCH2CH3, CH2NHCH3 NHCOC(CH3)2, or N(S(O)2CH3)2 substituent; R1 is hydrogen, halo, R4, CN, C(NOH)R3, C(NO-R4)R3, (CH)2CO2R4 , (CH2)n OR3 , COR3 , CF3,SR4 , S(O)R4, S(O)2R4, COCH2CO2R3 , NHSO2R4 , NHCOR3, C(NOR3)NH2, CH2OCOR3,(CH2)n NH2, CON(CH3)2 (CH2)nNHCO2R4 , CO2R3, CONH2, CSNH2, C(NH)NHOR3, (CH2)nN(CH3)2, or CONHNHCOR3; R2 is 1,2-ethenediyl or 1,2-ethynediyl; R3 is hydrogen or C1-C4 alkyl; R4 is C1-C4 alkyl; and n is 0, 1, 2,3 or 4; or a pharmaceutically acceptable salt thereof, or an N-oxide thereof.
Trifluoromethyl-substituted pyridines through displacement of iodine by in situ generated (trifluoromethyl)copper
Cottet, Fabrice,Schlosser, Manfred
, p. 327 - 330 (2007/10/03)
A literature method reported for iodobenzene and congeners was successfully extended to the pyridine series. 2-Iodopyridines can be converted into 2-(trifluoromethyl)pyridines almost quantitatively. In contrast, yields are moderate at best if 3- and 4-iodopyridines or 2-bromopyridines are used as the starting materials. WILEY-VCH Verlag GmbH 2002.
