Carbocyclization reaction of active methine compounds with unactivated alkenyl or alkynyl groups mediated by TiCl4-Et3N

Osamu Kitagawa, Takashi Suzuki, Tadashi Inoue, Yoko Watanabe, Takeo Taguchi

Research output: Contribution to journalArticle

70 Citations (Scopus)


In the presence of TiCl4, Et3N, and I2, iodocarbocyclization reaction of various active methine compounds having alkenyl groups gave iodocycloalkane derivatives in good yields. On the other hand, TiCl4 and Et3N promote the carbocyclization of active methine compounds with 4- alkynyl groups in the absence of I2 to give methylenecyclopentane derivatives in good yields. This reaction proceeds with high streoselectivity through a cis-addition of trichlorotitanium enolates of active methine compounds to alkynes, and the resulting vinyltitanium intermediates can be further functionalized by the reaction with various electrophiles.

Original languageEnglish
Pages (from-to)9470-9475
Number of pages6
JournalJournal of Organic Chemistry
Issue number25
Publication statusPublished - 1998 Dec 11


ASJC Scopus subject areas

  • Organic Chemistry

Cite this