Silylated cyclopentadienes as competent silicon Lewis acid catalysts

Abstract

Silicon Lewis acid donor catalysts incorporating highly electron-deficient cyclopentadienes are shown to catalyze C–C bond formation via anion abstraction.

Pentacarboxycyclopentadienes in Organic Synthesis

“…However, no attempts have been made to modify them to increase the catalytic activity. Silicon Lewis acids were obtained from cyclopentadienes with ester groups, the presence of which made it possible to modify these acids in order to increase their catalytic activity [81].…”

“…Radtkea and Lambert [81] showed that N-benzyland N-allylindoles reacted with high yields, whereas the yield with indole intelf was moderate. The alkylation of 1,3-dimethoxybenzene led to product 97f with a yield of 80%.…”

Highly Selective Ortho‐Directed Dicarboxylation of Cyclopentadiene by Methylcarbonates and CO2 or COS – First Insight into Co‐ordination Chemistry of New Ambident Ligands

“…These pentacarboxycyclopentadienes (PCCPs) have been used as cyclopentadienyl‐type ligands [40–42] in coordination chemistry. They served as a novel class of enantioselective Brønsted acid catalysts [43] and Lewis acids [44] . However, to the best of our knowledge, their potentially chelating carboxylate groups have never been used to bind a metal, e. g. next to a different (hetero)metal bound to the η 5 ‐cyclopentadienyl carbanion.…”

Hydrogen Bond Donor Catalyzed Cationic Polymerization of Vinyl Ethers

“…[22] To address this issue, we proposed that attenuation of the PCCP anion basicity would inhibit deprotonation and allow access to larger-molecular-weight polymers while maintaining the insensitivity of these polymerizations to moisture and nucleophilic impurities. This goal could be achieved through either modulation of the PCCP structure [23,24] or through additives that interact with the PCCP anion at the chain end. We chose to pursue the second approach because of the modularity of this strategy.…”