Vinyllithiums from butyl-vinyl tellurides and bis-vinyl tellurides
作者:Simone M. Barros、João V. Comasseto、Jorge Berriel
DOI:10.1016/s0040-4039(00)70695-2
日期:1989.1
Butyl vinyl tellurides and bis-vinyl tellurides furnish vinyllithiums with retention of configuration in good yields upon treatment with n-butyllithium at −78°C.
Selectivity on the reaction of vinylic tellurides with butyllithium in the presence of carbonyl compounds
作者:Miguel J. Dabdoub、Raquel G. Jacob、JoséT.B. Ferreira、Vânia B. Dabdoub、Francisco de A. Marques
DOI:10.1016/s0040-4039(99)01567-1
日期:1999.10
butyllithium in THF at −78 °C in the presence of a carbonylcompound such as benzaldehyde or cyclohexanone was studied. High selectivity of the attack at the tellurium atom was observed. In most cases, the corresponding allylic alcohol was obtained as the only (or major) product instead of the alcohols derived by the 1,2 addition of BuLi at the carbonylcompound. Similar results were obtained using
A chemo- and stereoselective Pd-catalysed semi-reduction of alkynes to (Z)-alkenes has been performed in a phosphonium-based DES by using the in situ generation of H2 from Al/H2O. The antitumor agent combretastatin A4 has been also synthesized.
通过利用 Al/H2O 原位生成 H2,在膦基 DES 中进行了炔烃到 (Z)- 烯的化学和立体选择性钯催化半还原反应。此外,还合成了抗肿瘤药物考布他丁 A4。