1,7-Electrocyclisations of 4-azaheptatrienyl lithium compounds to 4,5-dihydroazepines
作者:Stephanie Klötgen、Ernst-Ulrich Würthwein
DOI:10.1016/0040-4039(95)01480-6
日期:1995.9
6-heptatrienes 9, 10 at −78°C using lithium diisopropylamide as base yields 4-azaheptatrienyl lithium compounds 11. During warming up to room temperature (to 40°C for 10) they undergo a 1,7-electrocyclisation to afford 3-azacycloheptadienyl lithium compounds 13. Subsequent treatment with various electrophiles provides access to several substituted 4,5-dihydroazepines 14.
使用-二异丙基氨基锂作为碱,在-78°C下对4-氮杂1,3,6-庚基9、10进行质子化,生成4-氮杂庚三烯基锂化合物11。在升温至室温(至40°C,保持10 ℃ )的过程中,它们经历了1,7-电环化,从而得到3-氮杂环庚二烯基锂化合物13。随后用各种亲电试剂进行处理,可提供几种取代的4,5-二氢pine庚因14。