Reactions between Tantalum- or Niobium-Alkyne Complexes and Carbonyl Compounds

Yasutaka Kataoka, Jiro Miyai, Koichiro Oshima, Kazuhiko Takai, Kiitiro Utimoto

Research output: Contribution to journalArticle

61 Citations (Scopus)

Abstract

A variety of tantalum-alkyne complexes are generated in situ by treatment of alkynes with low-valent tantalum derived from TaCl5 and zinc. These complexes add regioselectively to carbonyl compounds in a one-to-one fashion to yield (E)-allylic alcohols stereoselectively. Iodinolysis of the oxatantalacyclopentene, which is postulated as an intermediate of the reaction, gives a (Z)-3-iodo-2-propen-1-ol derivative. In contrast to tantalum-alkyne complexes, niobium-alkyne complexes, prepared with low-valent niobium derived from NbCl5 and zinc, add in situ to aldehydes in a one-to-two fashion to give 1,3-diene derivatives. The dienes are produced through (i) addition of the alkyne complexes with 2 equiv of aldehydes at cis vicinal positions of the alkenes and (ii) deoxygenative elimination of 2,7-dioxanioba-4-cycloheptene complexes.

Original languageEnglish
Pages (from-to)1973-1981
Number of pages9
JournalJournal of Organic Chemistry
Volume57
Issue number7
DOIs
Publication statusPublished - Mar 1 1992
Externally publishedYes

    Fingerprint

ASJC Scopus subject areas

  • Organic Chemistry

Cite this