作者:Mariappan Periasamy、Athukuri Edukondalu、Polimera Obula Reddy
DOI:10.1021/jo502688b
日期:2015.4.3
Racemic 2,3-diaryl-1,4-diazabicyclo[2.2.2]octane (DABCO) derivatives are synthesized from the readily accessible piperazines in 50–64% yield by cyclization using ethylene bromide, triethylamine, and KI at 80 °C. The enantiomerically enriched 2,3-diphenylpiperazine and the 2,3-bis(1-naphthyl)piperazine derivatives are prepared by a resolution method using commercially available optically active acids
外消旋的2,3-二芳基-1,4-二氮杂双环[2.2.2]辛烷(DABCO)衍生物是由易于获得的哌嗪在80°C的条件下通过环化反应使用溴化乙烯,三乙胺和KI合成的,收率为50-64%。对映体富集的2,3-二苯基哌嗪和2,3-双(1-萘基)哌嗪衍生物是通过拆分方法使用市售的旋光酸制备的,相应的DABCO衍生物的收率为51-64%,最高可达99% %ee。这种温和的环化作用也可用于对映体纯的樟脑二胺衍生物,且产品收率为72–86%。