A novel hetergeneous mercury salt catalyst stabilized by m-carbaborane can be used and reused for various chemical reactions without leaching the metal.
一种新型的异质汞盐催化剂,由m-碳硼烷稳定,可用于各种化学反应,并可重复使用而不会溶出金属。
Hg(OTf)<sub>2</sub>-catalyzed Cycloisomerization of Aryl- and Hetero-substituted 1,3-Dienes
We developed Hg(OTf)2-catalyzed Friedel–Crafts-like cycloisomerization of 7-arylhepta-1,3-dienes to give propenyl-substituted tetrahydronaphthalenes in excellent catalytic turnover under very mild conditions. 1,3-Dienyl sulfonamides and 1,3-dienyl alcohols were also efficiently cyclized to afford heterocyclic compounds.
Novel Hg(OTf)(2)-Catalyzed arylene cyclization was achieved with highly efficient catalytic turnover (up to 200 times). The reaction takes place via protonation of allylic hydroxyl group by in situ formed TfOH of an organomercuric intermediate to generate a cationic species. Subsequent smooth demercuration regenerates the catalyst.
作者:Michael A. Schafroth、Stephan M. Rummelt、David Sarlah、Erick M. Carreira
DOI:10.1021/acs.orglett.7b01346
日期:2017.6.16
systems enabled through the combination of Lewis acid activation and iridium-catalyzedallylicsubstitution is described. The reaction proceeds with branched, allylic alcohols and carbon nucleophiles as well as heteronucleophiles to give a diverse set of ring systems in good yields and with high enantioselectivities. The utility of the method is highlighted by the asymmetric syntheses of erythrococcamides