Synthesis of Oxazolidinones by using Carbon Dioxide as a C1 Building Block and an Aluminium-Based Catalyst

Article abstract of DOI:10.1002/cssc.201901171

Oxazolidinone synthesis through the coupling of carbon dioxide and aziridines was catalysed by an aluminium(salphen) complex at 50–100 °C and 1–10 bar pressure under solvent-free conditions. The process was applicable to a variety of substituted aziridines, giving products with high regioselectivity. It involved the use of a sustainable and reusable aluminium-based catalyst, used carbon dioxide as a C₁ source and provided access to pharmaceutically important oxazolidinones as illustrated by a total synthesis of toloxatone. This protocol was scalable, and the catalyst could be recovered and reused. A catalytic cycle was proposed based on stereochemical, kinetic and Hammett studies.

Full text of DOI:10.1002/cssc.201901171

Accepted Article
Title: Synthesis of Oxazolidinones using Carbon Dioxide as a C-1
Building Block and an Aluminium-based Catalyst.
Authors: Mani Sengoden, Michael North, and Adrian Whitwood
This manuscript has been accepted after peer review and appears as an
Accepted Article online prior to editing, proofing, and formal publication
of the final Version of Record (VoR). This work is currently citable by
using the Digital Object Identifier (DOI) given below. The VoR will be
published online in Early View as soon as possible and may be different
to this Accepted Article as a result of editing. Readers should obtain
the VoR from the journal website shown below when it is published
to ensure accuracy of information. The authors are responsible for the
content of this Accepted Article.
To be cited as: ChemSusChem 10.1002/cssc.201901171
Link to VoR: http://dx.doi.org/10.1002/cssc.201901171
A Journal of
www.chemsuschem.org

10.1002/cssc.201901171
ChemSusChem
FULL PAPER
Synthesis of Oxazolidinones using Carbon Dioxide as a C-1
Building Block and an Aluminium-based Catalyst.
Mani Sengoden,[a] Michael North,*[a] and Adrian C. Whitwood[a]
Abstract: Oxazolidinone synthesis by the coupling of carbon dioxide
and aziridines is catalysed by an aluminium(salphen) complex at 50-
100 oC and 1-10 bar pressure under solvent-free conditions. The
process is applicable to a variety of substituted aziridines, giving
the development of catalysts for the synthesis of cyclic
carbonates from epoxides and carbon dioxide,[17] the conversion
of aziridines to oxazolidinones presented a new challenge with
additional complications due to the presence of a substituent on
the nitrogen atom of the aziridine and the possibility of forming
regioisomeric products. Herein we present an aluminium-based
catalyst for the coupling of aziridines with carbon dioxide at
moderate temperature under solvent-free conditions. The
reactions efficiently gave the corresponding oxazolidinones in
high yields.
products with high regioselectivity. It involves the use of
a
sustainable and reusable aluminium-based catalyst, uses carbon
dioxide as a C-1 source and provides access to pharmaceutically
important oxazolidinones as illustrated by a total synthesis of
toloxatone. This protocol is scalable and the catalyst can be
recovered and reused. A catalytic cycle is proposed based on
stereochemical, kinetic and Hammett studies.
Introduction
Utilization of carbon dioxide as a chemical feedstock is currently
attracting much interest[1] in both industry and academia, since it
is a safe, inexpensive and ubiquitous C-1 resource as well as
being the main greenhouse gas. The commercially viable
exploitation of carbon dioxide as a feedstock requires both the
production of large volume, low value chemicals and the
production of lower volume, high value products.[2] The reaction
of carbon dioxide with aziridines falls into the latter category and
is an efficient, atom-economic route for the preparation of
oxazolidinones which are important heterocyclic motifs found in
commercial pharmaceuticals[3] and which have a range of other
synthetic applications.[ 4 ] For example, antimicrobials such as
Figure 1. Examples of medicinally important oxazolidinones.
radezolid,[3b,c]
linezolid[3d]
and
eperezolid[3e]
and
the
Results and Discussion
antidepressant, toloxatone[3f] all contain an oxazolidinone
scaffold (Figure 1). Hence, the development of an
environmentally friendly approach for the synthesis of
oxazolidinones under mild reaction conditions is highly desirable.
The uncatalysed reaction of carbon dioxide with aziridines
requires specialized conditions (ball milling[ 5 ] or supercritical
carbon dioxide[6]) and is only applicable to a small number of
substrates. The reaction can be induced by catalytic or
stoichiometric amounts of metal salts,[7] metal complexes,[8] solid
metal phosphonates,[9] MOFs,[10] onium salts,[11] iodine,[12] -
amino acids,[ 13 ] N-heterocyclic carbenes[ 14 ] or polymers.[ 15 ]
However, all these systems have deficiencies with respect to
catalyst loading, carbon dioxide pressure, substrate scope
and/or need for toxic solvents.[16] Building on our experience in
Initial reactions were carried out using 1-benzyl-2-
phenylaziridine[15a] (1a) as substrate (Table 1). Pleasingly, 3-
benzyl-5-phenyloxazolidin-2-one (2a) was obtained as a single
regioisomer with 100% conversion when substrate 1a and
carbon dioxide (10 bar) were stirred with 2.5 mol% of aluminium
complex 3[18] (Figure 2) for 24 hours at 50 °C (entry 1). A similar
result was obtained, when the carbon dioxide pressure was
reduced to 5 bar (entry 2), though the conversion dropped
significantly when the carbon dioxide pressure was reduced to 1
bar (entry 3). The conditions of Table 1, entry 3 were then used
to screen the catalytic activity of complexes 4[19] and 5[20] (entries
4,5) and complex 5 was found to restore the complete
conversion of 1a into 2a (entry 5). Use of 1.5 mol% of catalyst 5
still gave 97% conversion (entry 6), but a significant reduction in
conversion to 77% was apparent when the catalyst loading was
further reduced to 1 mol% (entry 7). At room temperature, no
reaction occurred (entry 8) and a control experiment confirmed
that no reaction occurred in the absence of catalyst (entry 9).
Despite its rather complex looking structure, catalyst 5 is readily
available in just two steps from commercially available
chemicals.[16,20]
[a]
Dr. M. Sengoden, Prof. M. North and Dr. A. C. Whitwood
Department of Chemistry
University of York
York, UK, YO10 5DD
E-mail: Michael.north@york.ac.uk
Supporting information for this article is given via a link at the end of
the document.
This article is protected by copyright. All rights reserved.

10.1002/cssc.201901171
ChemSusChem
FULL PAPER
Table 1. Optimization of the reaction conditions.
Entry
CO2 [bar]
Catalyst [mol %]
3 (2.5)
3 (2.5)
3 (2.5)
4 (2.5)
5 (2.5)
5 (1.5)
5 (1.0)
5 (1.5)
-
T [°C]
50
t [h]
24
24
65
24
24
24
24
24
24
Conv. (%)[a]
1
2
3
4
5
6
7
8
9
10
5
100
100
41
50
1
50
1
50
59
1
50
100
97
Scheme 1. Substrate scope of the coupling of CO2 with aziridines catalysed
by complex 5.
1
50
1
50
77
Table 2. Synthesis of oxazolidinones 2a-r.
1
23
n.r.
n.r.
Substrate
CO2
[bar] [°C]
T
t [h]
Conv.
(%)[a]
Regioselectivty
Yield
(%)[b]
1
50
(2:2’)[a]
[a] Determined by 1H NMR spectroscopy. n.r. = no reaction.
1a
1b
1c
1d
1e
1f
1
1
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
100
100
24
24
24
24
44
32
24
24
24
24
24
24
24
40
24
24
24
97
100:0
95:5
94:6
96:4
95:5
100:0
89
84
91
89
72
83
100
99
1
1
100
100
100
0
1
1
1g
1h
1i
1
1
100
100
100
100
100
100
100
100
100
100
80:20
86:14
100:0
98:2
89
94
78
88
91
93
86
72
72
86
1
1j
1
1k
1l
1
1
94:6
Figure 2. Structures of complexes 3-5.
1m
1n
1o
1p
1q
1
94:6
1
90:10
The generality of the reaction under the conditions of Table 1,
entry 6 was examined using 17 aziridines[14c,15a,16, 21 ] 1a-q
(Scheme 1) and the results are presented in Table 2. Variously
N-substituted 2-phenylaziridines 1a-f underwent coupling with
CO2 to give products 2a-f in 72-91% isolated yields and with
regioselectivities of 95-100%. Substrates 1e,f with a secondary
alkyl group on the nitrogen atom required longer reaction times
to give complete conversions and substrate 1g with a tert-butyl
group on its nitrogen atom failed to react. These results are
1
10
10
[a] Determined by 1H NMR spectroscopy of the reaction mixture before
purification. n.r. = no reaction. [b] Total isolated yield of 2 and 2’ (when
present).
clearly indicative of
a mechanism in which complex 5
coordinates to the nitrogen atom of the aziridine. 2-Alkyl
aziridines, 1h,i were also good substrates, giving oxazolidinones
2h-i in 89-94% isolated yields with regioselectivities of at least
80%. N-Butyl 2-arylaziridines 1j-n with either electron-donating
or electron-withdrawing substituents on the aryl group gave
This article is protected by copyright. All rights reserved.

10.1002/cssc.201901171
ChemSusChem
FULL PAPER
oxazolidinones 2j-n in 78-93% yields and with at least 90%
regioselectivity. Notably, however, substrate 1n with a 4-
nitrophenyl substituent required a reaction time of 40 hours,
suggestive of a mechanism which involves a build-up of positive
charge at the benzylic position of the aziridine during the
mechanism. Bicyclic 2,3-disubstituted aziridines 1o-q were also
suitable substrates, giving oxazolidinones 2o-q. Cyclopentyl
aziridine 2o was highly reactive under the standard reaction
conditions (50 oC, 1 bar CO2, 24 hours), whilst cyclohexyl
aziridines 2p,q were less reactive and required a temperature of
100 oC with 10 bar CO2 pressure for 24 hours. The
stereochemistry of products 2p,q provides useful mechanistic
information and for both products, 1H and 13C NMR
spectroscopy indicated the formation of a single diastereomer. In
the case of 2q, this was unambiguously determined to be cis by
single crystal X-ray analysis (Figure 3).[16,22]
stereochemistry observed with bicyclic substrates 1p,q is the
result found in related reactions between carbon dioxide and
epoxides when the reaction occurs at the less substituted end of
the heterocycle.[24] To investigate this further, reactions were
carried out using deuterated trans-1i (90% deuterium
incorporation). As shown in Scheme 3, both regioisomeric
products: deuterated 2i and deuterated 2i’ were formed
exclusively as the trans-isomer. Deuterated 2i was again the
major product and arises from insertion of carbon dioxide into
the more substituted C-N bond of the aziridine. Hence,
whichever C-N bond of the aziridine carbon dioxide inserts into,
the reaction occurs with complete retention of the
stereochemistry of the aziridine.
Scheme 2. Total synthesis of toloxatone.
Figure 3. Ellipsoid diagram of the X-ray structure of compound 2q.
The above reactions were all carried out on a 0.5 mmol (ca
100 mg) scale. However, the reaction was found to be scalable
without difficulty. Thus, a reaction at 50 oC and 1 bar CO2
pressure using 4.18 g (20 mmol) of aziridine 1a gave 99%
conversion to oxazolidinone 2a which was isolated in 96% yield.
Catalyst 5 could be recovered in 95% yield simply by adding
acetonitrile to the reaction mixture and was then used to convert
aziridine 1d into oxazolidinone 2d with 100% conversion (87%
isolated yield) and 95% regioselectivity under the conditions of
Table 1, entry 6. Thus, complex 5 can be recovered and reused
without loss of catalytic activity.
Scheme 3. Reaction with deuterated trans-aziridine 1i.
To illustrate the applicability of the methodology, a total
synthesis of toloxatone[ 23 ] 2r was undertaken as shown in
Scheme 2. Thus, glycidyl acetate was converted in two steps
into aziridine 1r. Compound 1r could then be converted into
toloxatone 2r in 70% isolated yield by treatment with carbon
dioxide in the presence of catalyst 5. The optimal conditions for
To further probe the reaction mechanism, a Hammett plot
was constructed using kinetic data obtained using substrates
1a,j-n from reactions carried out at 50 oC and 1 bar carbon
dioxide pressure with dichloroethane as solvent.[16] The general
rate equation for the reaction is: rate = k[aziridine]a[CO2]b[5]c.
Since species 5 is a catalyst, and a large excess of carbon
dioxide was present, this simplifies to: rate = kobs[aziridine]a
where kobs = k[CO2]b[5]c. The disappearance of the aziridine was
monitored by 1H NMR spectroscopy and all reactions were found
to show a good fit to first order kinetics implying that a=1. The
resulting first order rate constants are given in Table 3.
o
this conversion were found to be 100 C and 10 bar of carbon
dioxide pressure.
The regiochemistry observed in reactions using substrates
1a-n and the slower rate of reaction of substrate 1n are
indicative of a mechanism that involves cleavage of the more
substituted C-N bond of the aziridine and at least partial
cleavage of this bond during the rate determining step of the
catalytic cycle. In contrast, the complete retention of
This article is protected by copyright. All rights reserved.

10.1002/cssc.201901171
ChemSusChem
FULL PAPER
Table 3. Kinetic data for the reaction of substrates 1a,j-n.
Substrate
Aromatic
kobs x 103 min-1 [a]

log[(kobsX)/(kobsH)]
substituent
1a
1j
H
-3.630 ± 0.000
-29.365 ± 1.145
-9.930 ± 0.540
-1.084 ± 0.185
-0.606 ± 0.022
-0.179 ± 0.001
0.00
-0.27
-0.17
0.23
0.23
0.78
0.00
0.91
0.44
-0.55
-0.78
-1.31
4-OMe
4-Me
4-Cl
1k
1l
1m
1n
4-Br
4-NO2
[a] Average of two, mutually consistent, separate experiments.
The Hammett plot constructed from the relative rate data in
Table 3 is shown in Figure 4 and has a negative slope, indicative
of a build-up of positive charge at the more hindered carbon
atom of the aziridine during the catalytic cycle. However, the
magnitude of the reaction constant (-2.1) is considerably smaller
than the -4 to -5 which is characteristic of reactions which
involve formation of a full positive charge at a benzylic position
during the rate determining step of the reaction.[25]
Scheme 4. Proposed catalytic cycle.
Conclusions
An efficient procedure for the synthesis of oxazolidinones by the
reaction of carbon dioxide with aziridines under mild reaction
conditions has been developed. The reaction is regioselective,
scalable and gives oxazolidinones in good to high yields. The
homogeneous catalyst can be recovered and reused and the
methodology has been used to prepare the antidepressant,
toloxatone. Mechanistic studies involving studies of the reaction
stereochemistry and kinetics suggested that the reaction occurs
at the more substituted carbon of the aziridine with overall
retention of configuration at this position. A catalytic cycle is
proposed which accounts for all of the experimentally observed
features. Compared to previously reported systems, the reaction
has wide substrate scope, requires a low catalyst loading, low
carbon dioxide pressure and occurs under solvent-free
conditions.
1
y = -2.07x + 0.07
R² = 0.91
4-MeO
4-Me
0.5
0
H

-0.4
-0.2
0
0.2
4-Cl
0.4
0.6
0.8
-0.5
-1
4-Br
4-NO2
-1.5
Figure 4. Hammett plot for the synthesis of oxazolidinones 2a,j-n catalysed by
complex 5.
Experimental Section
On the basis of the stereochemical, regiochemical and
kinetic evidence, the catalytic cycle shown in Scheme 4 is
proposed as the simplest mechanism that fits all of the data.
Chelation of aziridines 1 to complex 5 results in formation of
intermediate A in which the aziridine C–N bond best able to
support a partial positive charge is preferentially lengthened.
Intermediate A then undergoes aziridine ring-opening selectively
at the lengthened C–N bond to give intermediate B. Reaction of
intermediate B with carbon dioxide forms intermediate C which
can cyclize to form oxazolidinone 2 and regenerate catalyst 5.
Overall the catalytic cycle involves two substitution reactions,
each of which occurs with inversion of configuration, at the more
hindered carbon atom of the aziridine ring, explaining both the
regio- and stereochemistry. The build-up of partial positive
charge in intermediate A correctly accounts for the observed
kinetic data.
General Information. All chemicals were purchased from Sigma-Aldrich
and used as received. Aziridines 1a–g and 1j–n were prepared by the
method of Du et al.[15a] Aziridines 1h,I,o-q and 1-(3-methylphenyl)-2-
(acetoxymethyl)aziridine were prepared by the method of Anaya de
Parrodi et al.[21b] Metal complexes were prepared as previously
reported.[18,19,20] Reactions were monitored by analytical TLC on Merck
silica gel 60 F254 plates. Column chromatography was performed with
Aldrich silica gel (220-440 mesh). 1H and 13C NMR spectra were
recorded on a JEOL-400 spectrometer Chemical shifts (δ) are reported
relative to solvent signals (CHCl3, 7.26 ppm for 1H NMR and CDCl3 77.23
ppm for 13C NMR). Melting points were determined with a Stuart SMP20
apparatus and are uncorrected. FT-IR spectra were recorded using
PerkinElmer 400 spectrometer.
X-Ray Crystallography. Diffraction data were collected at 110 K on an
Oxford Diffraction SuperNova diffractometer with Cu-Kα radiation (λ=
1.54184 Å) using a EOS CCD camera. The crystal was cooled with an
Oxford Instruments Cryojet. Diffractometer control, data collection, initial
unit cell determination, frame integration and unit-cell refinement was
carried out with “Crysalis”.[26] Face-indexed absorption corrections were
This article is protected by copyright. All rights reserved.

10.1002/cssc.201901171
ChemSusChem
FULL PAPER
applied using spherical harmonics, implemented in SCALE3 ABSPACK
scaling algorithm.[27] OLEX2[28] was used for overall structure solution,
refinement and preparation of computer graphics and publication data.
Within OLEX2, the algorithms used for structure solution were “ShelXT
127.7, 61.6, 40.7, 38.1, 32.1, 20.7, 14.3 ppm. IR (neat): max = 3038,
2962, 2931, 2859 and 2817 cm-1; MS (ESI): calcd. for C12H17N35Cl (MH+)
210.1044, found 210.1043, 419.2011 [2M+H]+.
29
]
dual-space”.[
Refinement by full-matrix least-squares used the
1-Butyl-2-(4-bromophenyl)aziridine (1m). 1H NMR (400 MHz, CDCl3) 
= 7.40 (d J = 8.4 Hz, 2H, ArH), 7.12 (d J = 8.4 Hz, 2H, ArH), 2.51-2.45 (m,
1H, NCH2CH2), 2.34-2.27 (m, 1H, NCH2CH2), 2.24 (dd J = 6.4, 3.2 Hz,
1H, CHN), 1.82 (d J = 3.6 Hz, 1H, CH2N), 1.66 (d J = 6.4 Hz, 1H, CH2N),
1.61-1.54 (m, 2H, NCH2CH2), 1.42-1.33 (m, 2H, CH2Me), 0.90 (t J = 7.6
Hz, 3H, CH3) ppm; 13C NMR (100 MHz, CDCl3)  = 139.8, 131.4, 128.0,
120.5, 61.5, 40.7, 38.1, 32.1, 20.7, 14.3 ppm. IR (neat): max = 3045,
2957, 2930, 2867 and 2821 cm-1; MS (ESI): calcd. for C12H17N79Br (MH+)
254.0539, found 254.0536.
SHELXL-97[30] algorithm within OLEX2.[28] All non-hydrogen atoms were
refined anisotropically. Hydrogen atoms were placed by difference map
and allowed to refine.
General procedure for the coupling of aziridines with CO2 at
atmospheric pressure. A mixture of aziridine (0.5 mmol), and catalyst 5
(0.015 mmol) was stirred at 50 °C under CO2 (1 atm) for the appropriate
time, then the reaction was allowed to cool to room temperature. The
conversion of aziridine to oxazolidinones and the regioselectivity were
determined by 1H NMR analysis. The residue was purified by silica gel
column chromatography using EtOAc and petroleum ether as eluents to
give the corresponding oxazolidinones.
1
1-Butyl-2-(4-nitrophenyl)aziridine (1n). H NMR (400 MHz, CDCl3)  =
8.13 (d J = 8.8 Hz, 2H, ArH), 7.39 (d J = 8.8 Hz, 2H, ArH), 2.52-2.45 (m,
1H, NCH2CH2), 2.40-2.33 (m, 2H, NCH2CH2, CHN), 1.87 (d J = 2.8 Hz,
1H, CH2N), 1.78 (d J = 6.4 Hz, 1H, CH2N), 1.61-1.53 (m, 2H, NCH2CH2),
1.42-1.33 (m, 2H, CH2Me), 0.90 (t J = 7.2 Hz, 3H, CH3) ppm; 13C NMR
(100 MHz, CDCl3)  = 148.9, 146.9, 126.9, 123.7, 61.3, 40.6, 39.2, 32.0,
20.7, 14.2 ppm. IR (neat): max = 2958, 2932, 2871 and 1601 cm-1; MS
(ESI): calcd. for C12H17N2O2 (MH+) 221.1285, found 221.1288.
General procedure for the synthesis of oxazolidinones under
pressure. A mixture of aziridine (0.5 mmol), and catalyst 5 (0.015 mmol)
was placed in a stainless steel autoclave and the reactor was heated to
the desired temperature, then pressurised with CO2 to the required
pressure. The reaction mixture was stirred for 24 h, then the autoclave
was cooled in liquid nitrogen and excess CO2 vented. Conversion of
aziridine to oxazolidinones was determined by 1H NMR analysis. The
residue was purified by silica gel column chromatography using EtOAc
and petroleum ether as eluents to give the corresponding oxazolidinones.
1
7-(4-Nitrobenzyl)-7-azabicyclo[4.1.0]heptane (1q). H NMR (400 MHz,
CDCl3)  = 8.17 (d J = 8.8 Hz, 2H, ArH), 7.53 (d J = 8.8 Hz, 2H, ArH),
3.54 (s, 2H, NCH2), 1.89-1.76 (m, 4H, 2 x CH2), 1.66-1.64 (m, 2H,
2xNCH), 1.44-1.35 (m, 2H, CH2), 1.25-1.16 (m, 2H, CH2) ppm; 13C NMR
(100 MHz, CDCl3)  = 148.0, 146.9, 128.1, 123.6, 63.7, 38.9, 24.5, 20.6
ppm. IR (neat): max = 2933, 2855 and 1601 cm-1; MS (ESI): calcd. for
C13H17N2O2 (MH+) 233.1285, found 233.1284.
Synthesis of 1-(3-Methylphenyl)-2-(hydroxymethyl)aziridine (1r). A
mixture of 1-(3-methylphenyl)-2-(acetoxymethyl)aziridine (1 equiv.) and
NaOH (2 equiv.) in H2O was stirred at room temperature overnight. Then,
the reaction mixture was extracted with EtOAc (3x10 mL). The combined
organic extracts were dried (Na2SO4) and concentrated in vacuo. The
residue was purified by silica gel column chromatography using EtOAc
and petroleum ether (2:3) as eluent to give 1-(3-Methylphenyl)-2-
(hydroxymethyl)aziridine (1r) as a colourless liquid in 91% yield.
1-(3-Methylphenyl)-2-(hydroxymethyl)aziridine (1r). 1H NMR (400
MHz, CDCl3)  = 7.10 (t J = 7.6 Hz, 1H, ArH), 6.84-6.80 (m, 3H, ArH),
3.99-3.94 (m, 1H, CH2O), 3.59-3.50 (m, 2H, CH2O + OH), 2.39-2.34 (m,
1H, CHN), 2.30-2.28 (m, 4H, CH3, CH2N), 2.08 (d, J = 6.4 Hz, 1H, CH2N)
ppm; 13C NMR (100 MHz, CDCl3)  = 153.8, 139.0, 128.9, 123.8, 121.7,
118.1, 63.0, 41.0, 31.4, 21.5 ppm. IR (neat): max = 3339 and 2920 cm-1;
MS (ESI): calcd for C10H14NO (MH+) 164.1070, found 164.1068,
186.0887 [M+Na]+, 327.2062 [2M+H]+, 349.1881 [2M+Na]+.
Reaction kinetics. Catalyst 5 (0.015 mmol) was added to a 1M solution
of aziridine (0.5 mmol) in dichloroethane. The resulting solution was
stirred at 50 °C under CO2 (1 atm) and at appropriate time intervals,
samples were removed and analysed by 1H NMR spectroscopy to
determine the relative amounts of aziridine and oxazolidinones present.
All kinetic experiments were carried out in duplicate and gave consistent
results.
Characterizing data for oxazolidinones 2a-r.
3-Benzyl-5-phenyloxazolidin-2-one (2a).[15a] Analytical TLC on silica gel,
1:4 EtOAc/petroleum ether, Rf = 0.33; colourless solid; yield 89% (112
mg); M.p 68–69 °C (lit.[15a] 60–64 °C); 1H NMR (400 MHz, CDCl3) δ =
7.40-7.34 (m, 5H, ArH), 7.32-7.28 (m, 5H, ArH), 5.47 (t J = 8.4 Hz, 1H,
CHO), 4.57 (d J = 15.2 Hz, 1H, NCH2Ph), 4.42 (d J = 15.2 Hz, 1H,
NCH2Ph), 3.77 (t J = 8.8 Hz, 1H, CH2N), 3.31 (dd J = 8.8, 7.6 Hz, 1H,
CH2N) ppm; 13C NMR (100 MHz, CDCl3) δ = 158.1, 138.7, 135.7, 129.0,
128.9, 128.3, 128.2, 125.6, 74.7, 51.7, 48.5 ppm; IR (neat): max = 1739
cm-1; MS (ESI): calcd. for C16H16NO2 (MH+) 254.1176, found 254.1163,
276.0981 [M+Na]+.
Characterizing data for previously unreported aziridines.
1-Butyl-2-(4-methoxyphenyl)aziridine (1j). 1H NMR (400 MHz, CDCl3) 
= 7.17 (d J = 8.8 Hz, 2H, ArH), 6.84 (d J = 8.8 Hz, 2H, ArH), 3.78 (s, 3H,
OCH3), 2.51-2.45 (m, 1H, NCH2CH2), 2.32-2.23 (m, 2H, NCH2CH2
+
CHN), 1.85 (d J = 3.6 Hz, 1H, CH2N), 1.61-1.55 (m, 3H, CH2N,
NCH2CH2), 1.42-1.33 (m, 2H, CH2Me), 0.91 (t J = 7.2 Hz, 3H, CH3) ppm;
13C NMR (100 MHz, CDCl3)  = 158.7, 132.7, 127.4, 113.9, 61.7, 55.5,
41.0, 37.5, 32.2, 20.8, 14.3 ppm. IR (neat): max = 2932 and 2869 cm-1;
MS (ESI): calcd. for C13H20NO (MH+) 206.1539, found 206.1540, 411.307
[2M+H]+.
3-Allyl-5-phenyloxazolidin-2-one (2b).[31] Analytical TLC on silica gel,
1:4 EtOAc/petroleum ether, Rf = 0.23; pale yellow liquid; yield 84% (86
mg); 1H NMR (400 MHz, CDCl3)  = 7.40-7.32 (m, 5H, ArH), 5.82-5.72
(m, 1H, =CH2), 5.48 (t J = 7.6 Hz, 1H, CHO), 5.25-5.20 (m, 2H, CH=CH2),
3.96-3.82 (m, 3H, CH2N, CH2), 3.39 (t J = 7.6 Hz, 1H, CH2N) ppm; 13C
NMR (100 MHz, CDCl3)  = 157.8, 138.8, 131.9, 129.0, 128.9, 125.6,
118.9, 74.6, 51.9, 47.0 ppm; IR (neat): max = 1739 cm-1; MS (ESI): calcd.
for C12H14NO2 (MH+) 204.1019, found 204.1019, 226.0840 [M+Na]+.
1-Butyl-2-(4-chlorophenyl)aziridine (1l). 1H NMR (400 MHz, CDCl3)  =
7.25 (d J = 8.4 Hz, 2H, ArH), 7.17 (d J = 8.8 Hz, 2H, ArH), 2.50-2.44 (m,
1H, NCH2CH2), 2.33-2.27 (m, 1H, NCH2CH2), 2.25 (dd J = 6.4, 3.2 Hz,
1H, CHN), 1.82 (d J = 4.0 Hz, 1H, CH2N), 1.65 (d J = 6.8 Hz, 1H, CH2N),
1.60-1.53 (m, 2H, NCH2CH2), 1.42-1.32 (m, 2H, CH2Me), 0.90 (t, J = 7.2
Hz, 3H, CH3) ppm; 13C NMR (100 MHz, CDCl3)  = 139.3, 132.5, 128.5,
This article is protected by copyright. All rights reserved.

10.1002/cssc.201901171
ChemSusChem
FULL PAPER
3-Ethyl-5-phenyloxazolidin-2-one (2c).[8b] Analytical TLC on silica gel,
3:7 EtOAc/petroleum ether, Rf = 0.40; colourless liquid; yield 91% (87
mg); 1H NMR (400 MHz, CDCl3)  = 7.40-7.33 (m, 5H, ArH), 5.47 (t J =
8.4 Hz, 1H, CHO), 3.91 (t J = 8.8 Hz, 1H, CH2N), 3.44-3.29 (m, 3H, CH2N,
CH2), 1.16 (t J = 7.2 Hz, 3H, CH3) ppm; 13C NMR (100 MHz, CDCl3)  =
157.8, 138.9, 129.0, 128.9, 125.6, 74.4, 51.7, 39.0, 12.7 ppm; IR (neat):
max = 1738 cm-1; MS (ESI): calcd. for C11H14NO2 (MH+) 192.1019, found
192.1018, 214.0839 [M+Na]+.
8.8 Hz, 2H, ArH), 6.92 (d J = 8.8 Hz, 2H, ArH), 5.42 (t J = 8.4 Hz, 1H,
CHO), 3.85 (t J = 8.4 Hz, 1H, CH2N), 3.81 (s, 3H, OCH3), 3.41 (dd J = 8.4,
7.6 Hz, 1H, CH2N), 3.39-3.22 (m, 2H, NCH2), 1.58-1.50 (m, 2H, CH2),
1.40-1.31 (m, 2H, CH2), 0.94 (t J = 7.6 Hz, 3H, CH3) ppm; 13C NMR (100
MHz, CDCl3)  = 160.1, 158.1, 130.9, 127.3, 114.4, 74.5, 55.5, 52.3, 44.1,
29.6, 20.0, 13.9 ppm; IR (neat): max = 1728 cm-1; MS (ESI): calcd. for
C14H20NO3 (MH)+ 250.1438, found 250.1435, 272.1258 [M+Na]+.
3-Butyl-5-(4-methylphenyl)oxazolidin-2-one (2k).[14c] Analytical TLC on
silica gel, 1:3 EtOAc/petroleum ether, Rf = 0.40; colourless solid; yield
88% (103 mg); M.p 46–47 °C; 1H NMR (400 MHz, CDCl3)  = 7.25 (d J =
8.4 Hz, 2H, ArH), 7.20 (d J = 8.0 Hz, 2H, ArH), 5.44 (t J = 8.0 Hz, 1H,
CHO), 3.87 (t J = 8.8 Hz, 1H, CH2N), 3.40 (dd J = 8.4, 7.2 Hz, 1H, CH2N),
3.37-3.22 (m, 2H, NCH2), 2.35 (s, 3H, CH3), 1.57-1.49 (m, 2H, CH2),
1.40-1.30 (m, 2H, CH2), 0.93 (t J = 7.2 Hz, 3H, CH3) ppm; 13C NMR (100
MHz, CDCl3)  = 158.1, 138.8, 136.0, 129.7, 125.7, 74.5, 52.3, 44.1, 29.6,
21.3, 20.0, 13.9 ppm; IR (neat): max = 1728 cm-1; MS (ESI): calcd. for
C14H20NO2 (MH)+ 234.1489, found 234.1484, 256.1306 [M+Na]+.
3-Butyl-5-phenyloxazolidin-2-one (2d).[10c] Analytical TLC on silica gel,
1:4 EtOAc/petroleum ether, Rf = 0.29; colourless liquid; yield 89% (98
mg); 1H NMR (400 MHz, CDCl3)  = 7.41-7.33 (m, 5H, ArH), 5.47 (t J =
8.0 Hz, 1H, CHO), 3.90 (t J = 8.8 Hz, 1H, CH2N), 3.41 (dd J = 8.4, 7.6 Hz,
1H, CH2N), 3.37-3.22 (m, 2H, CH2), 1.57-1.49 (m, 2H, CH2), 1.39-1.30 (m,
2H, CH2), 0.93 (t J = 7.2 Hz, 3H, CH3) ppm; 13C NMR (100 MHz, CDCl3)
 = 158.0, 139.0, 129.0, 128.9, 125.6, 74.4, 52.3, 44.0, 29.5, 20.0, 13.8
ppm; IR (neat): max = 1740 cm-1; MS (ESI): calcd. for C13H18NO2 (MH+)
220.1332, found 220.1332, 242.1152 [M+Na]+.
3-Cyclopropyl-5-phenyloxazolidin-2-one (2e).[15a] Analytical TLC on
silica gel, 1:4 EtOAc/petroleum ether, Rf = 0.25; colourless solid; yield
72% (73 mg); M.p 60–61 °C (lit.[15a] 52–55 °C); 1H NMR (400 MHz,
CDCl3)  = 7.41-7.31 (m, 5H, ArH), 5.42 (t J = 8.0 Hz, 1H, CHO), 3.88 (t J
= 8.4 Hz, 1H, CH2N), 3.43 (dd J = 8.4, 7.6 Hz, 1H, CH2N), 2.59-2.54 (m,
1H, NCH), 0.85-0.68 (m, 4H, 2xCH2) ppm; 13C NMR (100 MHz, CDCl3) 
= 158.2, 138.7, 129.0, 128.9, 125.6, 74.6, 53.6, 26.0, 6.2, 5.7 ppm; IR
(neat): max = 1734 cm-1; MS (ESI): calcd. for C12H14NO2 (MH+) 204.1019,
found 204.1022, 226.0841 [M+Na]+.
3-Butyl-5-(4-chlorophenyl)oxazolidin-2-one (2l). Analytical TLC on
silica gel, 3:7 EtOAc /petroleum ether, Rf = 0.33; colourless solid; yield
91% (115 mg); M.p 53–55 °C; 1H NMR (400 MHz, CDCl3)  = 7.38 (d J =
8.8 Hz, 2H, ArH), 7.29 (d J = 8.8 Hz, 2H, ArH), 5.45 (t J = 8.8 Hz, 1H,
CHO), 3.90 (t J = 8.8 Hz, 1H, CH2N), 3.39-3.22 (m, 3H, CH2N, NCH2),
1.56-1.49 (m, 2H, CH2), 1.38-1.29 (m, 2H, CH2), 0.93 (t J = 7.2 Hz, 3H,
CH3) ppm; 13C NMR (100 MHz, CDCl3)  = 157.8, 137.6, 134.8, 129.3,
127.0, 73.7, 52.2, 44.1, 29.5, 20.0, 13.8 ppm; IR (neat): max = 1727 cm-1;
MS (ESI): calcd. for C13H1735ClNO2 (MH)+ 254.0942, found 254.0940,
276.0761 [M+Na]+.
3-Isopropyl-5-phenyloxazolidin-2-one (2f).[15a] Analytical TLC on silica
gel, 3:7 EtOAc/petroleum ether, Rf = 0.35; colourless liquid; yield 83%
(85 mg); 1H NMR (400 MHz, CDCl3)  = 7.41-7.33 (m, 5H, ArH), 5.46 (t J
= 8.4 Hz, 1H, CHO), 4.16 (septet J = 6.8 Hz, 1H, NCH), 3.85 (t J = 8.8 Hz,
1H, CH2N), 3.36 (dd J = 8.4, 7.6 Hz, 1H, CH2N), 1.22 (d J = 7.2 Hz, 3H,
CH3), 1.16 (d J = 6.8 Hz, 3H, CH3) ppm; 13C NMR (100 MHz, CDCl3)  =
157.3, 139.1, 129.0, 128.9, 125.6, 74.6, 47.5, 45.0, 20.2, 19.7 ppm; IR
(neat): max = 1736 cm-1; MS (ESI): calcd. for C12H16NO2 (MH+) 206.1176,
found 206.1179, 228.1000 [M+Na]+.
5-(4-Bromophenyl)-3-butyloxazolidin-2-one (2m). Analytical TLC on
silica gel, 1:3 EtOAc/petroleum ether, Rf = 0.22; colourless solid; yield
93% (139 mg); M.p 80–81 °C; 1H NMR (400 MHz, CDCl3)  = 7.53 (d J =
8.4 Hz, 2H, ArH), 7.23 (d J = 8.4 Hz, 2H, ArH), 5.43 (t J = 8.4 Hz, 1H,
CHO), 3.90 (t J = 8.8 Hz, 1H, CH2N), 3.38-3.21 (m, 3H, CH2N, NCH2),
1.56-1.48 (m, 2H, CH2), 1.38-1.29 (m, 2H, CH2), 0.92 (t J = 7.6 Hz, 3H,
CH3) ppm; 13C NMR (100 MHz, CDCl3)  = 157.8, 138.1, 132.2, 127.3,
122.9, 73.7, 52.2, 44.1, 29.5, 20.0, 13.8 ppm; IR (neat): max = 1724 cm-1;
MS (ESI): calcd. for C13H1779BrNO2 (MH)+ 298.0437, found 298.0435,
320.0258 [M+Na]+.
3-Benzyl-5-butyloxazolidin-2-one (2h).[32] Analytical TLC on silica gel,
1:4 EtOAc/petroleum ether, Rf = 0.29; colourless liquid; yield 89% (104
mg); 1H NMR (400 MHz, CDCl3)  = 7.37-7.27 (m, 5H, ArH), 4.49-4.35 (m,
3H, CHO, NCH2Ph), 3.45 (t J = 8.4 Hz, 1H, CH2N), 3.00 (dd J = 8.4, 7.2
Hz, 1H, CH2N), 1.76-1.64 (m, 1H, CH2), 1.60-1.52 (m, 1H CH2), 1.41-
1.24 (m, 4H, 2xCH2), 0.88 (t J = 6.8 Hz, 3H, CH3) ppm; 13C NMR (100
MHz, CDCl3)  = 158.3, 135.9, 128.9, 128.2, 127.9, 73.7, 49.3, 48.3, 34.7,
26.6, 22.4, 13.9 ppm; IR (neat): max = 1738 cm-1; MS (ESI): calcd. for
C14H20NO2 (MH)+ 234.1489, found 234.1479, 256.1297 [M+Na]+.
3-Butyl-5-(4-bromophenyl)oxazolidin-2-one (2n). Analytical TLC on
silica gel, 2:3 EtOAc/petroleum ether, Rf = 0.24; yellow liquid; yield 86%
(114 mg); 1H NMR (400 MHz, CDCl3)  = 8.25 (d J = 8.8 Hz, 2H, ArH),
7.54 (d J = 8.8 Hz, 2H, ArH), 5.59 (dd J = 8.8, 7.6 Hz, 1H, CHO), 4.00 (t J
= 8.8 Hz, 1H, CH2N), 3.38 (dd J = 8.8, 7.2 Hz, 1H, CH2N), 3.37-3.21 (m,
2H, CH2), 1.55-1.47 (m, 2H, CH2), 1.34-1.28 (m, 2H, CH2), 0.90 (t J = 7.2
Hz, 3H, CH3) ppm; 13C NMR (100 MHz, CDCl3)  = 157.4, 148.1, 146.2,
126.3, 124.3, 73.1, 51.9, 44.1, 29.4, 19.9, 13.7 ppm; IR (neat): max
=
1743 cm-1; MS (ESI): calcd. for C13H17N2O4 (MH)+ 265.1183, found
265.1181, 287.1004 [M+Na]+.
3-Benzyl-5-octyloxazolidin-2-one (2i). Analytical TLC on silica gel, 1:4
EtOAc/petroleum ether, Rf = 0.33; colourless liquid; yield 94% (136 mg);
1H NMR (400 MHz, CDCl3)  = 7.37-7.25 (m, 5H, ArH), 4.49-4.36 (m, 3H,
CHO, NCH2Ph), 3.45 (t J = 8.8 Hz, 1H, CH2N ), 3.00 (dd J = 8.4, 7.2 Hz,
1H, CH2N), 1.74-1.66 (m, 1H, CH2), 1.58-1.51 (m, 1H, CH2), 1.42-1.24 (m,
12H, 6xCH2), 0.86 (t J = 6.8 Hz, 3H, CH3) ppm; 13C NMR (100 MHz,
CDCl3)  = 158.3, 136.0, 128.9, 128.2, 128.0, 73.8, 49.4, 48.4, 35.1, 31.9,
29.5, 29.4, 29.3, 24.6, 22.8, 14.2 ppm; IR (neat): max = 1741 cm-1; MS
(ESI): calcd. for C18H28NO2 (MH)+ 290.2115, found 290.2113, 312.1931
[M+Na]+.
3-Benzylhexahydro-2H-cyclopenta[d]oxazol-2-one (2o).[33] Analytical
TLC on silica gel, 2:3 EtOAc/petroleum ether, Rf = 0.38; colourless liquid;
yield 72% (78 mg); 1H NMR (400 MHz, CDCl3)  = 7.36-7.27 (m, 5H,
ArH), 4.87-4.84 (m, 1H, CHO), 4.76 (d J = 15.2 Hz, 1H, NCH2Ph), 4.06 (d
J = 15.2 Hz, 1H, NCH2Ph), 3.96 (t J = 6.8 Hz, 1H, CHN), 2.08-2.04 (m,
1H, CH2), 1.87-1.83 (m, 1H, CH2), 1.70-1.60 (m, 3H, CH2CH2), 1.43-1.33
(m, 1H, CH2) ppm; 13C NMR (100 MHz, CDCl3)  = 158.5, 136.2, 128.9,
128.3, 128.0, 79.2, 59.6, 46.7, 34.0, 30.5, 22.2 ppm; IR (neat): max
=
1731 cm-1; MS (ESI): calcd. for C13H16NO2 (MH)+ 218.1176, found
218.1175, 240.0993 [M+Na]+.
3-Butyl-5-(4-methoxyphenyl)oxazolidin-2-one (2j). Analytical TLC on
silica gel, 1:3 EtOAc/petroleum ether, Rf = 0.27; colourless solid; yield
1
78% (98 mg); M.p 58–59 °C; H NMR (400 MHz, CDCl3)  = 7.29 (d J =
This article is protected by copyright. All rights reserved.

10.1002/cssc.201901171
ChemSusChem
FULL PAPER
3-Benzylhexahydrobenzo[d]oxazol-2(3H)-one (2p).[31] Analytical TLC
on silica gel, 2:3 EtOAc/petroleum ether, Rf = 0.40; pale yellow liquid;
yield 72% (83 mg); 1H NMR (400 MHz, CDCl3)  = 7.34-7.27 (m, 5H,
ArH), 4.77 (d J = 14.8 Hz, 1H, NCH2), 4.45 (q J = 5.2 Hz, 1H, CHO), 4.05
(d J = 15.2 Hz, 1H, NCH2), 3.48 (q J = 5.6 Hz, 1H, CHN), 1.94-1.86 (m,
1H, CH2), 1.77-1.69 (m, 2H, CH2), 1.57-1.37 (m, 4H, 2xCH2), 1.24-1.18
(m, 1H, CH2) ppm; 13C NMR (100 MHz, CDCl3)  = 159.0, 136.4, 128.8,
128.2, 127.9, 73.5, 53.6, 45.8, 27.0, 25.4, 19.7, 19.6 ppm; IR (neat): max
= 1741 cm-1; MS (ESI): calcd. for C14H18NO2 (MH)+ 232.1332, found
232.1332, 254.1150 [M+Na]+.
[5]
C. Phung, R. M. Ulrich, M. Ibrahim, N. T. G. Tighe, D. L. Lieberman, A.
R. Pinhas, Green Chem. 2011, 1, 3224–3229.
[6]
[7]
X.-Y. Dou, L.-N. He, Z.-Z. Yang, J.-L. Wang, Synlett 2010, 2159–2163.
a) M. T. Hancock, A. R. Pinhas, Tetrahedron Lett. 2003, 44, 5457–5460;
b) A. Sudo, Y. Morioka, E. Koizumi, F. Sanda, T. Endo, Tetrahedron
Lett. 2003, 44, 7889–7891; c) A. Sudo, Y. Morioka, F. Sanda, T. Endo,
Tetrahedron Lett. 2004, 45, 1363–1365; d) Y. Wu, L.-N. He, Y. Du, J.-Q.
Wang, C.-X. Miao, W. Li, Tetrahedron 2009, 65, 6204–6210; e) H.
Matsuda, A. Ninagawa, H. Hasegawa, Bull. Chem. Soc. Jpn. 1985, 58,
2717–2718; f) Y. Wu, G. Liu, Tetrahedron Lett. 2011, 52, 6450–6452.
a) A. W. Miller, S. T. Nguyen, Org. Lett. 2004, 6, 2301–2304; b) W.-M.
Ren, Y. Liu, X-B. Lu, J. Org. Chem. 2014, 79, 9771–9777; c) D.
Adhikari, A. W. Miller, M.-H. Baik, S. T. Nguyen, Chem. Sci. 2015, 6,
1293–1300; d) S. Arayachukiat, P. Yingcharoen, S. V.C. Vummaleti, L.
Cavallo, A. Poater, V. D’Elia, Mol. Catal. 2017, 443, 280–285; e) Y. Xie,
C. Lu, B. Zhao, Q. Wang, Y. Yao, J. Org. Chem. 2019, 84, 1951–1958.
a) T. Y. Ma, S. Z. Qiao, ACS Catal. 2014, 4, 3847–3855; b) X.-Z. Lin, Z.-
Z. Yang, L.-N. He, Z.-Y. Yuan, Green Chem. 2015, 17, 795–798.
[8]
[9]
3-(4-Nitrobenzylhexahydrobenzo[d]oxazol-2(3H)-one (2q). Analytical
TLC on silica gel, 2:3 EtOAc/petroleum ether, Rf = 0.25; colourless solid;
yield 86% (119 mg); M.p 68–69 °C; 1H NMR (400 MHz, CDCl3)  = 8.19
(d J = 8.8 Hz, 2H, ArH), 7.48 (d J = 8.8 Hz, 2H, ArH), 4.77 (d J = 16.0 Hz,
1H, NCH2), 4.52 (q J = 5.6 Hz, 1H, CHO), 4.24 (d J = 16.0 Hz, 1H, NCH2),
3.54 (q J = 6.4 Hz, 1H, CHN), 1.95-1.89 (m, 1H, CH2), 1.82-1.74 (m, 2H,
CH2), 1.57-1.40 (m, 4H, 2xCH2), 1.28-1.22 (m, 1H, CH2) ppm; 13C NMR
(100 MHz, CDCl3)  = 159.1, 147.7, 144.2, 128.8, 124.1, 73.8, 54.3, 45.5,
27.0, 25.6, 19.8, 19.6 ppm; IR (neat): max = 1742 cm-1; MS (ESI): calcd.
for [C14H17N2O4]+ 277.1183, found 277.1180, 299.1001 [M+Na]+.
[10] a) H. Xu, X.-F. Liu, C.-S. Cao, B. Zhao, P. Cheng, L.-N. He, Adv. Sci.
2016, 3, 1600048; b) X. Wang, W.-Y. Gao, Z. Niu, L. Wojtas, J. A.
Perman, Y.-S. Chen, Z. Li, B. Aguila, S. Ma, Chem. Commun. 2018, 54,
1170–1173; c) C.-S. Cao, Y. Shi, H. Xu, B. Zhao, Dalton Trans. 2018,
47, 4545–4553.
5-(Hydroxymethyl)-3-(3-methylphenyl)oxazolidin-2-one (toloxatone)
[11] a) C. Phung, A. R. Pinhas, Tetrahedron Lett. 2010, 51, 4552–4554; b)
Z.-Z. Yang, L.-N. He, S.-Y. Peng, A.-H. Liu, Green Chem. 2010, 12,
1850–1854; c) Z.-Z. Yang, Y.-N. Li, Y.-Y. Wei, L.-N. He, Green Chem.
2011, 13, 2351–2353; d) H. Zhou, G.-X. Wang, W.-Z. Zhang, X.B. Lu,
ACSCatal. 2015, 5, 6773–6779.
(2r).[34] Analytical TLC on silica gel, 3:2 EtOAc/petroleum ether, Rf = 0.09;
1
white solid; yield 70% (72 mg); M.p 78–79 °C (lit.[34] 75–76 °C); H NMR
(400 MHz, CDCl3)  = 7.37 (s, 1H, ArH), 7.31 (d J = 8.4 Hz, 1H, ArH),
7.24 (t J = 8.0 Hz, 1H, ArH), 6.96 (d J = 7.6 Hz, 1H, ArH), 4.74-4.68 (m,
1H, CHN), 4.03-3.92 (m, 3H, CH2N, CH2OH), 3.76-3.70 (m, 1H, CH2OH),
2.80 (t J = 6.8 Hz, 1H, OH), 2.35 (s, 3H, CH3) ppm; 13C NMR (100 MHz,
CDCl3)  = 155.1, 139.2, 138.1, 129.0, 125.2, 119.3, 115.6, 73.1, 62.9,
46.6, 21.8 ppm; IR (neat): max = 3481, 2912, 1722, 1419, 1233 cm-1; MS
(ESI): calcd. for C11H14NO3 (MH)+ 208.0968, found 208.0968, 230.0788
[M+Na]+.
[12] H. Kawanami, Y. Ikushima, Tetrahedron Lett. 2002, 43, 3841–3844.
[13] a) H.-F. Jiang, J.-W. Ye, C.-R. Qi, L.-B. Huang, Tetrahedron Lett. 2010,
51, 928–932; b) X.-Y. Dou, L.-N. He, Z.-Z. Yang, Synth. Commun. 2012,
42, 62–74.
[14] a) J. Seayad, A. M. Seayad, J. K. P. Ng, C. L. L. Chai, ChemCatChem
2012, 4, 774–777; b) A. Ueno, Y. Kayaki, T. Ikariya, Green Chem. 2013,
15, 425–430; c) V. B. Saptal, B. M. Bhanage, ChemSusChem 2016, 9,
1980–1985; d) A.-H. Liu, Y.-L. Dang, H. Zhou, J.-J. Zhang, X-B. Lu,
ChemCatChem 2018, 10, 2686–2692.
Acknowledgements
[15] a) Y. Du, Y. Wu, A.-H. Liu, L.-N. He, J. Org. Chem. 2008, 73, 4709–
4712; b) C. Qi, J. Ye, W. Zeng, H. Jiang, Adv. Synth. Catal. 2010, 352,
1925–1933; c) R. A. Watile, D. B. Bagal, K. M. Deshmukh, K. P. Dhake,
B. M. Bhanage, J. Mol. Catal A. 2011, 351, 196–203; d) A. C.
Kathalikkattil, J. Tharun, R. Roshan, H.-G. Soek, D.-W. Park, App.
Catal. A. 2012, 447-448, 107–114; e) R. A. Watile, B. M. Bhanage,
Indian J. Chem. A. 2012, 51, 1354–1360. (f) V. Saptal, D. B. Shinde, R.
Banerjee, B. M. Bhanage, Catal. Sci. Technol. 2016, 6, 6152–6158.
[16] See supporting information.
The authors thank the Science & Engineering Research Board
(SB/OS/PDF-092/2016-17), New Delhi, India for a fellowship (to
MS).
Keywords: Aluminium catalysis • aziridines • carbon dioxide
fixation • oxazolidinones • Schiff bases
[17] For examples see: a) D. O. Meléndez, A. Lara-Sánchez, J. Martínez, X.
Wu, A. Otero, J. A. Castro-Osma, M. North, R. S. Rojas,
ChemCatChem 2018, 10, 2271–2277; b) S. A. Kuznetsova, Y. A. Rulev,
V. A. Larionov, A. F. Smol'yakov, Y. V. Zubavichus, V. I. Maleev, H. Li,
M. North, A. S. Saghyan, Y. N. Belokon, ChemCatChem 2019, 11, 511–
519; c) P. A. Carvalho, J. W. Comerford, K. J. Lamb, M. North, P. S.
Reiss, Adv. Syn. Catal. 2019, 361, 345–354; d) X. Wu, C. Chen, Z. Guo,
M. North, A. C. Whitwood, ACSCatal. 2019, 9, 1895–1906.
[1]
a) M. Aresta, A. Dibenedetto, A. Angelini, Chem. Rev. 2014, 114, 1709–
1742; b) Q. Liu, L. Wu, R. Jackstell, M. Beller, Nat. Commun. 2015, 6,
5933–5947; c) B. Yu, L.-N. He, ChemSusChem 2015, 8, 52–62; d) New
and Future Developments in Catalysis, Activation of Carbon Dioxide
(Ed.: S. L. Suib), Elsevier B. V. 2013; e) Carbon Dioxide Utilization:
Closing the Carbon Cycle (Ed.: P. Styring, E. A. Quadrelli and K.
Armstrong), Elsevier B. V., 2014; f) D. T. Allen, C. Tran, E. Zeitler, ACS
Sustainable Chem. Eng. 2019, 7, 3702−3709.
[18] W. Clegg, R. W. Harrington, M. North, P. A. Villuendas, J. Org. Chem.
2010, 75, 6201–6207.
[2]
[3]
M. North, ChemSusChem 2019, 12, 1763–1765
For examples see: a) D. J. Diekema, R. N. Jones, Drugs 2000, 59, 7–
16; b) S. Lemaire, P. M. Tulkens, F. Van Bambeke, Antimicrob. Agents
Chemother. 2010, 54, 2540–2548; c) K. Michalska, E. Bednarek, E.
Gruba, K. Lewandowska, M. Mizera, J. Cielecka-Piontek, Chem. Cent.
J. 2017, 11, 82; d) T. Niemi, T. Repo, Eur. J. Org. Chem. 2019, 1180–
1188.
[19] J. A. Castro-Osma, M. North, X. Wu, Chem. Eur. J. 2016, 22, 2100–
2107.
[20] X. Wu, M. North, ChemSusChem 2017, 10, 74–78.
[21] a) K. J. Shaw, J. R. Luly, H. Rapoport, J. Org. Chem. 1985, 50, 4515–
4523; b) C. Anaya de Parrodi, V. Vázquez, L. Quintero, E. Juaristi,
Synth. Commun. 2001, 31, 3295–3302; c) C. Miniejew, F. Outurquin, X.
Pannecoucke, Org. Biomol. Chem. 2004, 2, 1575–1576; d) D.
[4]
S. G. Davies, A. M. Fletcher, P. M. Roberts, J. E. Thomson, Org.
Biomol. Chem. 2019, 17, 1322–1335.
This article is protected by copyright. All rights reserved.

10.1002/cssc.201901171
ChemSusChem
FULL PAPER
Stephens, Y. Zhang, M. Cormier, G. Chavez, H. Arman, O. V. Larionov,
Chem. Commun. 2013, 49, 6558–6560; e) T. J. Senter, M. C. O’Reilly,
K. M. Chong, G. A. Sulikowski, C. W. Lindsley, Tetrahedron Lett. 2015,
56, 1276–1279.
[24] J. A. Castro-Osma, M. North, W. K. Offermans, W. Leitner, T. E. Müller,
ChemSusChem 2016, 9, 791–794.
[25] A. Williams Free Energy Relationships in Organic and Bio-organic
Chemistry; RSC: Cambridge, 2003.
[22] CCDC 189567 contains the supplementary crystallographic data for this
[26] CrysAlisPro, Oxford Diffraction Ltd. Version 1.171.34.41
[27] Empirical Absorption Correction Using Spherical Harmonics,
Implemented in SCALE3 ABSPACK Scaling Algorithm Within
CrysAlisPro Software, Oxford Diffraction Ltd. Version 1.171.34.40
[28] Dolomanov, O. V.; Bourhis, L. J.; Gildea, R. J.; Howard, J. A. K.;
Puschmann, H. OLEX2: a Complete Structure Solution, Refinement
and Analysis Program. J. Appl. Cryst., 2009, 42, 339–341.
paper.
These
data
can
be
obtained
free
or
of
charge
by
via www.ccdc.cam.ac.uk/data_request/cif,
emailing data_request@ccdc.cam.ac.uk, or by contacting The
Cambridge Crystallographic Data Centre, 12 Union Road,386
Cambridge CB2 1EZ, UK; fax: +44 1223 336033.
[23] For previous syntheses of toloxatone see: a) S. Cacchi, G. Fabrizi, A.
Goggiamani, Heterocycles 2003, 61, 505–512; b) B. Mallesham, B. M.
Rajesh, P. Rajamohan Reddy, D. Srinivas, S. Trehan, Org. Lett. 2003,
5, 963–965; c) J. Li, Y. Zhang, Y. Jiang, D. Ma, Tetrahedron Lett. 2012,
53, 3981–3983; d) W. Mahy, P. K. Plucinski, C. G. Frost, Org. Lett.
2014, 16, 5020–5023; e) J. Rintjema, R. Epping, G. Fiorani, E. Martín,
E. C. Escudero-Adán, A. W. Kleij, Angew. Chem. Int. Ed. 2016, 55,
3972–3976; f) Y. Toda, S. Gomyou, S. Tanaka, Y. Komiyama, A.
Kikuchi, H. Suga, Org. Lett. 2017, 19, 5786–5789; g) W. Paisuwan, T.
Chantra, P. Rashatasakhon, M. Sukwattanasinitt, A. Ajavakom,
Tetrahedron 2017, 73, 3363–3367; h) Y. Lee, J. Choi, H. Kim, Org. Lett.
2018, 20, 5036–5039; i) W. Yi, X.-X. Fang, Q.-Y. Liu, G.-Q. Liu, Eur. J.
Org. Chem. 2018, 6671–6681.
[29] Sheldrick, G. M. SHELXT – Integrated Space-Group and Crystal-
Structure Determination. Acta Cryst. 2015, A71, 3–8.
[30] Sheldrick, G. M. A Short History of SHELX. Acta Cryst. 2008, A64,
112–122.
[31] A. Baba, K. Seki, H. Matsuda, J. Org. Chem. 1991, 56, 2684–2688.
[32] M. Lv, P. Wang, D. Yuan, Y. Yao, ChemCatChem 2017, 9, 4451–4455.
[33] J. Sepúlveda-Arques, T. Armero-Alarte, A. Acero-Alarcón, E. Zaballos-
García, B. Y. Solesio, J. E. Carrera, Tetrahedron 1996, 52, 2097–2102.
[34] W. Paisuwan, T. Chantra, P. Rashatasakhon, M. Sukwattanasinitt, A.
Ajavakom, Tetrahedron 2017, 73, 3363–3367.
This article is protected by copyright. All rights reserved.

10.1002/cssc.201901171
ChemSusChem
FULL PAPER
Entry for the Table of Contents
FULL PAPER
Mani Sengoden, Michael North* and
Adrian C. Whitwood
Page No. – Page No.
Synthesis of Oxazolidinones using
Carbon Dioxide as a C-1 Building
Block and an Aluminium-based
Catalyst
The synthesis of oxazolidinones by the coupling of CO2 with aziridines catalysed by
an aluminium complex is reported. Oxazolidinones are obtained in good to high
yields, The process is scalable, the catalyst can be reisolated and reused and the
chemistry has been applied to the synthesis of the antidepressant, toloxatone.
This article is protected by copyright. All rights reserved.