Highly Selective Carboxylative Cyclization of Allenylmethylamines with Carbon Dioxide Using N-Heterocyclic Carbene-Silver(I) Catalysts
摘要:
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.
Direct Conversion of CO 2 in Lime Kiln Waste Gas Catalyzed by a Copper‐Based N ‐heterocyclic Carbene Porous Polymer
作者:Zhi-Xiu Rao、Pei-Bo Chen、Jin Xu、Qing Wang、Hai-Tao Tang、Ying Liang、Ying-Ming Pan
DOI:10.1002/cssc.202300170
日期:——
copper-based N-heterocyclic carbene porous polymer (Cu@NHC-1) with triple synergistic catalytic effect on the conversion of CO2 via carboxylative cyclization was successfully fabricated to convert CO2 in limekiln waste gas into value-added oxazolidinones, providing a prospect for the direct utilization of low concentration CO2 in industrial waste gas.
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.
Visible‐Light Promoted Intramolecular
<i>para</i>
‐Cycloadditions on Simple Aromatics
We present the first synthesis of bridged bicycles through the dearomatization of sterically and electronically unbiased aryl fragments. The visible-light promoted method occurs at room temperature and has ample functional-group tolerance. The key to the difunctionalization of the aryl partner is the use of naphthalene as an additive, which stabilizes transient (bi)radicals through its extended π cloud