Nickel (0) -Mediated Intramolecular Cyclization.

Abstract

Nickel (0) -mediated intramolecular cyclizations of enynes and diynes have mainly been described. The article includes the following topics. (1) Cyclization of 1, n-enynes and dienynes with isocyanides to produce polycyclic iminocyclopentenes. (2) Cyclization of 1, n-diynes with isocyanides to form polycyclic iminocyclopentadienes. (3) Cyclization of 1, 6-diynes with “silylenes” to produce bicyclic silacyclopentadienes. (4) Cyclization of 1, 7-diynes with hydrosilanes to form 1, 2-dialkylidenecyclohexanes bearing a (Z) -vinylsilane moiety. (5) Cyclization of bis-dienes with hydrosilanes to give 1, 2-divinylcyclopentanes having an allylsilane moiety. Properties, reactivities and synthetic utilities of new ring systems thus obtained are also described.