Jian-Hui Liu, H. Chan, F. Xue
Feb 9, 1999
Citations
0
Influential Citations
26
Citations
Journal
The Journal of organic chemistry
Abstract
3,4-Bis(trimethylsilyl)-1H-pyrrole (5) was employed as a key precursor to generate a highly strained and reactive five-membered cyclic cumulene, namely 1-tert-butoxycarbonyl-3,4-didehydro-1H-pyrrole (4). The transient existence of 4 at room temperature was confirmed by trapping reactions with furan, acrylonitrile, and benzene, affording cycloadducts 13-15. The choice of the electron-withdrawing tert-butoxycarbonyl group as the N-substituent was essential because it was able to adjust the electron density of 11a and 11b. As a result, monoiodonium triflates 12a and 12b were obtained, respectively. On the contrary, N-tert-butyl-3,4-bis(trimethylsilyl)-1H-pyrrole (9) led instead to the bisiodonium triflate 10 upon treatment with the Zefirov reagent.