Metal-free CO2 fixation: conversion of epoxides to cyclic carbonates by a highly efficient bifunctional boron-tethered N-heterocyclic nitrenium catalyst
The development of sustainable, metal-free catalytic platforms for the chemical fixation of carbon dioxide (CO2) into value-added products remains a formidable challenge. Herein, we report the rational design of a highly efficient bifunctional organoboron catalyst, featuring a Lewis acidic boron center tethered to an N-heterocyclic nitrenium ion, for the solvent-free cycloaddition of CO2 to epoxides. This system exhibits enhanced catalytic activity and recyclability, delivering a broad range of cyclic carbonates in excellent yields under neat conditions. Thorough mechanistic studies reveal the key transient intermediates in the reaction pathway. Notably, our catalyst demonstrates the highest activity among the metal-free systems reported to date for the coupling of CO2 to propylene oxide under ambient conditions (TOF = 12.4 h−1, 25 °C, 1 bar), establishing this organoboron framework as a remarkably robust and green catalyst.
The chemical reduction of carbon dioxide (CO2) into value-added C1 building blocks, particularly under sustainable, metal-free conditions, remains a profound challenge in modern catalysis. Herein, we report robust boron-tethered N-heterocyclic nitrenium (NHN) catalysts for the reduction of CO2 under ambient conditions...
The cycloaddition of carbon dioxide (CO2) to epoxides is an attractive route for sustainable chemical synthesis, yet many metal-based catalytic systems require co-catalysts, suffer from limited recyclability, or exhibit inefficient mass transport. Herein, we report a bifunctional heterogeneous catalyst (I−Ni-AP-PHTS)...
Arian Ajal-Afshar, A. Tavakoli, M. Khorasani· ACS Applied Engineering Mate...· 0 citations
Efficient carboxylative cyclization of propargylic amines with CO2 is of great significance for the synthesis of value-added oxazolidinones and the sustainable utilization of carbon resources. However, this transformation is generally limited by the use of noble-metal catalysts, high temperatures, and high-purity CO2...
Ming-Li Huang, Xue-Feng He, Chun-Yang Li et al.· Crystal Growth & Design· 0 citations
The chemical fixation of CO2 into cyclic carbonates represents an efficient atom-economical route to valorize this almost unreactive greenhouse gas. In this work, a series of metal-free, guanylated cyclophosphazenes (1–3) were synthesized and evaluated as organocatalysts for the cycloaddition of CO2 to different epoxid...
Oscar A. Douglas-Gallardo, F. Werlinger, Julio I. Urzúa et al.· Molecules· 0 citations
Blue LED‐driven conversion of CO
2
into value‐added products under mild conditions remains a primary challenge in sustainable synthetic methods. Herein, we report a B–N fused phenanthroimidazolyl Zn–salen complex catalysed protocol for carboxylation of terminal alkynes using CO
2
at atmospheric pressure under blu...
Sasmita Dhala, Priyabrat Dash, S. Tripathy et al.· Annalen der Pharmacie· 0 citations
Hydroformylation is a 100% atom-economy industrial process that converts olefins and syngas to aldehydes, typically catalyzed by homogeneous Rh phosphine or phosphite complexes, though catalyst recovery and ligand stability remain persistent challenges. Here, we theoretically investigate HRh(CO)2 fragments supported...
