Efficient
Synthesis of Quinazoline-2,4(1H,3H)‑dione via Simultaneous Activated CO2 and 2‑Aminobenzonitrile
by 1‑Methylhydantoin
Anion-Functionalized Ionic Liquid through the Multiple-Site Cooperative
Interactions
posted on 2022-08-02, 10:03authored byTingting Chen, Yunfei Zhang, Yingjie Xu
A novel basic anion-functionalized ionic liquid with
a 1-methylhydantoin
anion ([1-MHy]−) and [P4442]+ cation was synthesized for efficient CO2 capture and
catalytic conversion of CO2 to quinazoline-2,4(1H,3H)-dione, and CO2 absorption
and conversion mechanisms were investigated by NMR, FT-IR, and DFT
calculations. CO2 absorption results show that the capture
capacity of [P4442][1-MHy] at 303.15 K and 0.1 MPa is up
to 1.58 molCO2/molIL, which is attributed to
the multiple-site cooperative interactions between CO2 with
N– and CO of [1-MHy]− originated
from the electron conjugation effect, resulting in a decrease in the
CO2 absorption enthalpy (−51.4 kJ/mol) and an increase
in the activation of CO2. Moreover, the high yield of quinazoline-2,4(1H,3H)-dione obtained by using [P4442][1-MHy] to catalyze 2-aminobenzonitrile with atmospheric-pressure
CO2 was 97% and is solvent- and metal-free. The reaction
mechanism indicates that [1-MHy]− with the multiple-site
cooperative interactions can not only activate CO2 but
also can activate 2-aminobenzonitrile by forming two types of hydrogen
bonds with −NH2 (N–H···N– and N–H···OC), thus
ensuring the excellent catalytic performance of [P4442][1-MHy].
Furthermore, due to the similar basicity of [1-MHy]− to the quinazolide anion ([Quinazolide]−), it
can effectively prevent the deprotonation of the acidic quinazoline-2,4-dione
into [Quinazolide]−, thereby improving its yield.
In addition, [P4442][1-MHy] has good recycling performance
during CO2 capture and conversion. The physicochemical
properties of [P4442][1-MHy] are also reported. The obtained
results may provide a new strategy for converting CO2 into
value-added chemicals under green conditions.