水素化ジイソブチルアルミニウムによる分子内炭素-炭素および炭素-ケイ素結合形成反応の開発

抄録

Diisobutylaluminum hydride (DIBAL-H) is a common reagent in synthetic organic chemistry, and well known as a reducing agent of carbonyl groups and C-C multiple bonds. DIBAL-H is also used for modifications of alkynes. The preparation of haloalkenes via hydroalumination of alkynes and following halodemetallation of the resultant alkenylaluminums is the prime example. However, application of the alkenylaluminums to intramolecular bond formation remained largely unexplored. Recently, our attention has been focused on the reactivity and synthetic use of α-silylalkenylaluminums readly prepared from alkynylsilanes and DIBAL-H. During the course of our research, we succeeded in developing new cyclization reactions by DIBAL-H-promoted C-C and C-Si bond formation, which are valuable for regio-controlled syntheses of substituted benzenes, naphthalenes, indenes, benzosiloles, and siloles. These studies have provided not only efficient synthetic methods for carbocycles and silacycles but also novel information on the reactivity of organoaluminums.