Premium
Synthesis of N ‐alkyl‐ N ′‐aryl or Alkenylpiperazines: A Copper‐Catalyzed C–N Cross‐Coupling in the Presence of Aryl and Alkenyl Triflates and DABCO
Author(s) -
GhazanfarpourDarjani Majid,
BaratSeftejani Forugh,
Khalaj Mehdi,
MousaviSafavi Seyed Mahmoud
Publication year - 2017
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.201700082
Subject(s) - chemistry , dabco , aryl , alkyl , octane , bicyclic molecule , halide , medicinal chemistry , piperazine , copper , organic chemistry
Unsymmetrical piperazines are key constituents of many pharmaceuticals. Given that the selective introduction of an aryl and alkyl motif onto the piperazine is not always straightforward, direct arylation and alkenylation of 1,4‐diaza‐bicyclo[2.2.2]octane would obviate the inefficiencies associated with the preparation of these target molecules. We have utilized alkyl halides, aryl or alkenyl triflates, and 1,4‐diaza‐bicyclo[2.2.2]octane for the synthesis of N ‐alkyl‐ N ′‐aryl or alkenylpiperazines. The optimum conditions are developed using CuCl, t ‐Bu OL i in NMP . Alkenyl triflates requires N , N ′‐dimethylethylenediamine and higher temperature to afford the desired cross‐coupled product. Substrates bearing electron‐deficient and electron‐rich groups were successfully coupled under the optimum reaction conditions.