Metallation versus heteroatom lithium complexation: Mono- and dilithiation of dipyridylpiperazines
BuLi-LiDMAE induced the efficient lithiation of dipyridylpiperazines despite strong competing lithium coordination by several nitrogen atoms. Symmetrical substrates led to a one-pot dilithiation while dissymmetrical species gave mono- or dilithiation under temperature control. Georg Thieme Verlag Stuttgart.
SYNTHESIS OF NEW ARMED CYCLOPOLYAMINES AND THEIR SELECTIVE EXTRACTION PROPERTIES FOR METAL IONS
A variety of new armed cyclopolyamines were prepared by high presure SNAr reactions (0.8 GPa, 100 deg C) of cyclopolyamines with heteroaromatic halides.Certain of these agents show selective extraction properties for Hg2+ and Ag+ ions.
Matsumoto, Kiyoshi,Fukuyama, Keisuke,Iida, Hirokazu,Toda, Mitsuo,Lown, J. William
Amination of 2-Pyridinesulfonic and 8-Quinolinesulfonic Acids with Magnesium Amides
The amination of 2-pyridine- and 8-quinolinesulfonic acids using magnesium amides of the type R2NMgCl·LiCl is reported. Thus, several cyclic and acyclic amines were converted into the corresponding amides using iPrMgCl·LiCl, which reacted readily with sulfonic acids to produce aminopyridines and aminoquinolines. Various amines which are attractive in drug chemistry were suitable for this transformation.
Balkenhohl, Moritz,Valsamidou, Vasiliki,Knochel, Paul
supporting information
p. 5165 - 5168
(2019/02/27)
Nickel-catalysed selective N-arylation or N,N′-diarylation of secondary diamines
The selective synthesis of N-aryl or N,N′-diaryl piperazines and trimethylene(bis)piperidines from the corresponding diamines and aryl chlorides using a catalyst combination of Ni(0) associated to 2,2′-bipyridine is described. The Ni/2,2′-bipyridine catalyst is also effective for the sequential arylation of piperazine. The preparation of novel and unsymmetrical 1,4-diaryl piperazines is reported.
Brenner, Eric,Schneider, Rapha?l,Fort, Yves
p. 6913 - 6924
(2007/10/03)
Nickel-mediated amination chemistry. Part 2: Selective N-arylation or N,N'-diarylation of piperazine
The 2,2'-bipyridine liganded Ni catalyst has revealed a good selectivity in the mono arylation of piperazine starting from aryl chlorides allowing a selective and efficient synthesis of N-arylpiperazines using stoichiometric amounts of reagents. The preparation of N,N'-diaryl substituted piperazines is also described. (C) 2000 Elsevier Science Ltd.
Brenner, Eric,Schneider, Rapha?l,Fort, Yves
p. 2881 - 2884
(2007/10/03)
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