One-pot catalytic synthesis of urea derivatives from alkyl ammonium carbamates using low concentrations of CO2

Hiroki Koizumi,Kazuhiro Matsumoto,Seiji Matsumoto,Masahito Uchida,Norihisa Fukaya,Jun-Chul Choi,Satoshi Hamura,Katsuhiko Takeuchi,Kazuhiko Sato

doi:10.1038/s42004-021-00505-2

Hiroki Koizumi, Kazuhiro Matsumoto + Show 7 more

Open Access

https://doi.org/10.1038/s42004-021-00505-2

Copy DOI

Abstract

To reduce anthropogenic carbon dioxide (CO2) emissions, it is desirable to develop reactions that can efficiently convert low concentrations of CO2, present in exhaust gases and ambient air, into industrially important chemicals, without involving any expensive separation, concentration, compression, and purification processes. Here, we present an efficient method for synthesizing urea derivatives from alkyl ammonium carbamates. The carbamates can be easily obtained from low concentrations of CO2 as present in ambient air or simulated exhaust gas. Reaction of alkyl ammonium carbamates with 1,3-dimethyl-2-imidazolidinone solvent in the presence of a titanium complex catalyst inside a sealed vessel produces urea derivatives in high yields. This reaction is suitable for synthesizing ethylene urea, an industrially important chemical, as well as various cyclic and acyclic urea derivatives. Using this methodology, we also show the synthesis of urea derivatives directly from low concentration of CO2 sources in a one-pot manner.

Highlights

To reduce anthropogenic carbon dioxide (CO2) emissions, it is desirable to develop reactions that can efficiently convert low concentrations of CO2, present in exhaust gases and ambient air, into industrially important chemicals, without involving any expensive separation, concentration, compression, and purification processes
We have developed an efficient method for the synthesis and isolation of alkyl ammonium carbamates from aliphatic amines and low concentrations of CO2, including CO2 from ambient air
A method for the Cp2Ti(OTf)2-catalyzed synthesis of urea derivatives from alkyl ammonium carbamates, which can be obtained from low concentrations of CO2, including those in exhaust gases and ambient air, was developed

Summary

Introduction

To reduce anthropogenic carbon dioxide (CO2) emissions, it is desirable to develop reactions that can efficiently convert low concentrations of CO2, present in exhaust gases and ambient air, into industrially important chemicals, without involving any expensive separation, concentration, compression, and purification processes. Reaction of alkyl ammonium carbamates with 1,3-dimethyl-2-imidazolidinone solvent in the presence of a titanium complex catalyst inside a sealed vessel produces urea derivatives in high yields This reaction is suitable for synthesizing ethylene urea, an industrially important chemical, as well as various cyclic and acyclic urea derivatives. The synthesis of urea derivatives from amines and atmospheric CO2, with an equivalent amount of phosphine and trichloroisocyanuric acid as a sacrificial reagent, has been reported[29] These studies are, important as they provide methods for utilizing less reactive CO2 as a C1 building block. Considering the above facts, we inferred that the development of a reaction to synthesize urea derivatives from low concentrations of CO2, without the need for CO2 concentration, compression, and purification, could be a useful method for reducing

Methods

Results

Conclusion