Cyclobutane forming [2+2]-cycloaddition reactions of allylsilane with electron-deficient olefin is promoted by triflic imide (Tf2NH). Triflic imide is converted in situ to silyl triflic imide (R3SNTf2), which serves as the actual catalyst for this process. When these reactions take place at higher than ambient temperatures, thermodynamically more stable anti-cyclobutanes are generated preferentially by equilibration of the initially formed adducts via retro [2+2]-cycloaddition. (c) 2006 Elsevier Ltd. All rights reserved.
Five-membered ring annulation via propargyl- and allylsilanes
作者:Rick L. Danheiser、Brian R. Dixon、Robert W. Gleason
DOI:10.1021/jo00049a006
日期:1992.11
Allyl- and propargylsilanes can serve as three-carbon components in a [3 + 2] annulation strategy for the synthesis of five-membered carbocycles and heterocycles.
[3+2] cydoadditions of allylsilanes, Part 3. diastereoselective construction of two contiguous quaternary carbon centers by [3+2] cycloaddition of allyltrisisopropylsilane
作者:Hans-Joachim Knölker、Regina Graf
DOI:10.1016/s0040-4039(00)74083-4
日期:1993.7
A diastereoselective synthesis of 1,2-annulated and spiroannulated bicyclic ring systems with concomitant generation of two contiguous quaternary carbon atoms is achieved by [3+2] cycloaddition of allyltrisisopropylsilane to the appropriate enones.