Catalytic Conversion of Carbon Dioxide through C-N Bond Formation

Abstract

From the viewpoint of green chemistry and sustainable development, it is of great significance to synthesize chemicals from CO₂ as C₁ source through C-N bond formation. During the past several decade years, many studies on C-N bond formation reaction were involved, and many efforts have been made on the theory. Nevertheless, several great challenges such as thermodynamic limitation, low catalytic efficiency and selectivity, and high pressure etc. are still suffered. Herein, recent advances are highlighted on the development of catalytic methods for chemical fixation of CO₂ to various chemicals through C-N bond formation. Meanwhile, the catalytic systems (metal and metal-free catalysis), strategies and catalytic mechanism are summarized and discussed in detail. Besides, this review also covers some novel synthetic strategies to urethanes based on amines and CO₂. Finally, the regulatory strategies on functionalization of CO₂ for N-methylation/N-formylation of amines with phenylsilane and heterogeneous catalysis N-methylation of amines with CO₂ and H₂ are emphasized.

Keywords: C-N bond formation; carbon dioxide utilization; chemicals; hydrogenation; reaction mechanism; synthetic methods.

Scheme 1

CO₂ conversion through C-N bond formation reactions described in this work.

Scheme 2

The mechanism for three-component reaction of propargylic alcohols, amines and CO_2.

Scheme 3

Catalytic systems for the reactions of CO₂, propargylic alcohols and primary amines.

Figure 1

Some 2-oxazolidinone derivatives by Ag₂WO₄/Ph₃P system (isolated yields are given) [21].

Figure 2

¹H-NMR (a,b) and ¹³C-NMR (c–f) investigation. (a,b) 2-Methyl-4-phenylbut-3-yn-2-ol (8.0 mg), Ag₂CO₃ (2.8 mg) and Ph₃P (10.5 mg) ([D₆] DMSO 0.6 mL). (c,d) 2-methylbut-3-yn-2-ol (20.2 mg), AgNO₃ (40.8 mg) (CDCl₃ 0.6 mL). (e) [(Ph₃P)₂Ag]₂CO₃ (158.6 mg) in 0.6 mL of CDCl₃. (f) [(Ph₃P)₂Ag]₂CO₃ (158.6 mg) in 0.6 mL of CDCl₃ in the presence of ¹³CO₂ (0.1 MPa). Reprinted with permission from [32] (Copyright 2014 John Wiley and Sons).

Figure 3

The scope of the [(PPh₃)₂Ag]₂CO₃ reaction system (isolated yields are given). Reprinted with permission from [32] (Copyright 2014 John Wiley and Sons).

Scheme 4

A plausible mechanism for propargylic alcohols with ammonium carbamates [33].

Scheme 5

The mechanism for carboxylative cyclization of propargylic amines with CO_2.

Scheme 6

A summary of coinage metals catalysts in carboxylative cyclization of propargylic amines with CO_2.

Scheme 7

Synthesis of 2-oxazolidinones via Zn- and Pd-catalyzed reaction.

Scheme 8

Synthesis of 2-oxazolidinones by metal-free catalytic systems.

Scheme 9

Synthesis of 2-oxazolidinones through carbonylation of amino alcohols with CO_2.

Scheme 10

Synthesis of 2-oxazolidinones through thermodynamically favourable approach [68].

Scheme 11

Possible reaction pathway of 2-aminobenzonitrile and CO_2.

Scheme 12

IL-catalyzed transformation of 2-aminobenzonitrile and CO_2.

Figure 4

¹H-NMR spectra of (a) 2-aminobenzonitrile with (b) [HMIm][Im] (pKa value of cation was 7.1), (c) [HDBU][Im] (pKa value of cation was 11.7) or (d) [HMTBD][Im] (pKa value of cation was 13.0). The H signal of amino in 2-aminobenzonitrile became broader when the basicity of cation was higher. Reprinted with permission from [81] (Copyright 2018 American Chemical Society).

Scheme 13

Synthesis of quinazoline-2,4(1H,3H)-dione by heterogeneous catalysts.

Scheme 14

Multicomponent reactions including CO₂ to synthesize quinazoline-2,4(1H,3H)-diones.

Scheme 15

Bicyclic guanidine-catalyzed urea formation.

Figure 5

Various ureas by CeO₂/NMP system. Reprinted with permission from [92] (Copyright 2015 Elsevier Inc.).

Scheme 16

Synthesis of polyureas via the polymerization of CO₂ with diamines.

Figure 6

(1) FTIR spectra of (a) TOTDDA, (b) DBU, and (c) mixture of TOTDDA and DBU (TOTDDA:DBU was 10:1). The protonation of DBU by TOTDDA indicated that DBU could activate the -NH₂ group of TOTDDA. (2) In situ ATR-FTIR spectra of DBU (C=N) and DBU·CO₂ (C=O) collected at different periods of reaction time. The new band at 1644 cm⁻¹ is assignable to C=O and this implies the formation of the complex of DBU·CO₂. Reaction conditions: DBU 2 mmol, CO₂ 8 MPa, 60 °C. Reprinted with permission from [98] (Copyright 2018 John Wiley and Sons).

Scheme 17

N-tosylhydrazones as a building block to construct C-N bonds.

Scheme 18

Synthesis of O-aryl carbamates by three-component reactions containing amines and CO_2.

Scheme 19

Syntheses of N-arylcarbamates via various strategies.

Figure 7

(a) ¹H- and (b) ¹⁵N-NMR spectra of aniline with and without Zn(OAc)₂/phen in CD₃CN at room temperature. The chemical shifts in both ¹H and ¹⁵N-NMR spectra illustrated the interaction between aniline and acetate, and the formation of hydrogen bonds. Reprinted with permission from ref. [107] (Copyright 2017 John Wiley and Sons).

Scheme 20

Synthesis of allyl carbamates from amines and CO_2.

Scheme 21

Zinc complex-catalyzed methylation of amines using hydrosilanes.

Scheme 22

Fe-based catalysis for temperature controlled N-formylation/N-methylation.

Scheme 23

Thiazolium carbene-based catalyst for N-formylation/N-methylation.

Scheme 24

TBAF catalysis for selective N-formylation/N-methylation.

Scheme 25

Cs₂CO₃ catalysis for selective N-formylation/N-methylation and proposed mechanism.

Scheme 26

Glycine betaine-catalyzed selective N-formylation/N-methylation.

Scheme 27

DBU-catalyzed selective N-methylation/N-formylation using PMHS as hydride reagent [128].

Scheme 28

Pressure-switched N-methylation/N-formylation to methylamine/formamide.

Scheme 29

DBU-catalyzed selective N-methylation/N-formylation and possible mechanism [130].

Scheme 30

Proposed mechanistic pathways for N-methylation and N-formylation [131].

Scheme 31

TBD-catalyzed aminal synthesis from amine, CO₂ and hydrosilane [132].

Scheme 32

Summarized control experiments in the published work.

Scheme 33

Proposed mechanism for reduction of aminal [131].

Scheme 34

Heterogeneous metal-based catalysis methylation of ammonia.

Scheme 35

Au-catalyzed methylation of amine with CO₂ and H_2.

Scheme 36

Reaction route of PdGa-catalyzed methylation of N-methylaniline [141].

Scheme 37

Heterogeneous palladium catalysis N-formylation of amines [147].