Intramolecular Hydroalkoxylation of Unactivated Alkenes Using Silane–Iodine Catalytic System
摘要:
A novel catalytic system using I-2 and PhSiH3 for the intramolecular hydroalkoxylation of unactivated alkenes is described. NMR study indicated that in situ generated PhSiH2I is a possible active catalytic species. This catalytic system allows an efficient intramolecular hydroalkoxylation of phenyl-, trialkyl-, and 1,1-dialkyl-substituted alkenes as well as a variety of unactivated monoalkyl- and 1,2-dialkyl-substituted alkenes at room temperature. Mechanistic consideration based on significant experimental observations is also discussed.
catalyzed intramolecular hydroalkoxylation reaction is presented, as a transition metal free, inexpensive, and very mild process for the highly atom economic formation of cyclic ethers from γ,δ-unsaturated alcohols. In contrast to most of the previously reported procedures, roomtemperature conditions are fully sufficient in most cases for a high yielding cycloisomerization in the presence of a combination
Platinum-Catalyzed Intramolecular Hydroalkoxylation of γ- and δ-Hydroxy Olefins to Form Cyclic Ethers
作者:Hua Qian、Xiaoqing Han、Ross A. Widenhoefer
DOI:10.1021/ja0477773
日期:2004.8.1
4-diphenyltetrahydrofuran in 78% yield. The platinum-catalyzed hydroalkoxylation of γ-hydroxy olefins tolerated substitution at the α, β, and γ-carbon atoms and at the internal and cis and trans terminal olefinic positions. Platinum-catalyzed hydroalkoxylation tolerated a number of functional groups including pivaloate and acetate esters, amides, silyl and benzyl ethers, and pendant hydroxyl and olefinic groups