Highly selective carboxylative cyclization of allenylmethylamines with carbon dioxide using N-heterocyclic carbene-silver(I) catalysts.
Silver(I) carboxylate complexes promote the carboxylative cyclization of allenylmethylamines to afford 5-alkenyl-1,3-oxazolidin-2-ones in 2-propanol. The use of an N-heterocyclic carbene ligand (IPr) under pressurized CO2 is effective in suppressing the intramolecular hydroamination that leads to 2,5-dihydropyrroles. The mechanism involving a nucleophilic attack of the carbamate of the allene moiety and a subsequent protonation was realized on the basis of experimental and theoretical results involving a model intermediate, the alkenylgold(I) complex, which was synthesized from Au(OH)(IPr) and 1-methylamino-2,3-butadiene.
Department of Applied Chemistry, Graduate School of Science and Engineering, Tokyo Institute of Technology, O-okayama 2-12-1-E4-1, Meguro-ku, Tokyo 152-8552, Japan.
Kyohei
K
Yamashita
Department of Applied Chemistry, Graduate School of Science and Engineering, Tokyo Institute of Technology, O-okayama 2-12-1-E4-1, Meguro-ku, Tokyo 152-8552, Japan.
Shun
S
Hase
Department of Applied Chemistry, Graduate School of Science and Engineering, Tokyo Institute of Technology, O-okayama 2-12-1-E4-1, Meguro-ku, Tokyo 152-8552, Japan.
Yoshihito
Y
Kayaki
Department of Applied Chemistry, Graduate School of Science and Engineering, Tokyo Institute of Technology, O-okayama 2-12-1-E4-1, Meguro-ku, Tokyo 152-8552, Japan.
Takao
T
Ikariya