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Updated: May 21, 2026

A Two-Step Protocol for Umpolung Functionalization of Ketones Via Enolonium Species
Published on: August 16, 2018
Sequential protocol for C(sp3)-H carboxylation with CO2: transition-metal-catalyzed benzylic C-H silylation and
Tsuyoshi Mita1, Kenichi Michigami, Yoshihiro Sato
1Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo 060-0812, Japan. tmita@pharm.hokudai.ac.jp
Abstract:
One of the most challenging transformations in current organic chemistry is the catalytic carboxylation of a C(sp(3))-H bond using CO(2) gas, an inexpensive and ubiquitous C1 source. A sequential protocol for C(sp(3))-H carboxylation by employing a nitrogen-directed, metal-assisted, C-H activation/catalytic silylation reaction in conjunction with fluoride-mediated carboxylation with CO(2) was established. The carboxylation proceeded only at the benzylic C(sp(3))-Si bond, not at the aromatic C(sp(2))-Si, which is advantageous for further manipulations of the products.
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