Silver(I)-Catalyzed Three-Component Reaction of Propargylic Alcohols, Carbon Dioxide and Monohydric Alcohols: Thermodynamically Feasible Access to β-Oxopropyl Carbonates

Article abstract of DOI:10.1002/asia.201600600

A silver(I)-catalyzed three-component reaction of propargylic alcohols, CO₂, and monohydric alcohols was successfully developed for the synthesis of β-oxopropyl carbonates. As such, a series of β-oxopropyl carbonates were exclusively produced in excellent yields (up to 98 %), even under atmospheric pressure of CO₂. The silver catalyst works efficiently for both the carboxylative cyclization of propargylic alcohols with CO₂ and subsequent transesterification of α-alkylidene cyclic carbonates with monohydric alcohols; thus this tandem process performs smoothly under mild conditions. This work provides a versatile and thermodynamically favorable approach to dissymmetric dialkyl carbonates.

Full text of DOI:10.1002/asia.201600600

CHEMISTRY
AN ASIAN JOURNAL
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Accepted Article
Title: Silver(I)-Catalyzed Three-Component Reaction of Propargylic Alcohols, CO2
and Monohydric Alcohols: Thermodynamically Feasible Access to β-Oxopropyl
Carbonates
Authors: Zhi-Hua Zhou; Qing-Wen Song; Jia-Ning Xie; Ran Ma; Liang-Nian He
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Chemistry - An Asian Journal
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Silver(I)-Catalyzed Three-Component Reaction of Propargylic
Alcohols, CO2 and Monohydric Alcohols: Thermodynamically
Feasible Access to β-Oxopropyl Carbonates
Zhi-Hua Zhou,[a] Qing-Wen Song,[a] Jia-Ning Xie,[a] Ran Ma,[a] and Liang-Nian He*[a, b]
Abstract:
Silver(I)-catalyzed
three-component
reaction
of
α-Alkylidene cyclic carbonates, a kind of functionalized
propargylic alcohols, CO2, and monohydric alcohols was
successfully developed for the synthesis of β-oxopropyl carbonates.
As such, a series of β-oxopropyl carbonates were exclusively
produced in excellent yields (up to 98%) even under atmospheric
pressure of CO2. Silver catalyst in this study works efficiently for both
the carboxylative cyclization of propargylic alcohols with CO2, and
subsequent transesterification of α-alkylidene cyclic carbonates with
monohydric alcohols, thus renders this tandem process performing
smoothly under mild conditions. The present work provides a
versatile and thermodynamically favorable approach to dissymmetric
dialkyl carbonates.
carbonates, have been obtained efficiently from propargylic
alcohols and CO2.[9] On the other hand, the transesterification of
α-alkylidene cyclic carbonates with monohydric alcohols was
found to afford β-oxopropyl carbonates (Scheme 1c).[2a,10] As a
consequence, β-oxopropyl carbonates can be prepared through
a two-step process including the formation and isolation of α-
alkylidene cyclic carbonates, and subsequent transesterification
with monohydric alcohols. We envisaged that one-pot process
i.e. the three-component reaction of propargylic alcohols, CO2,
and monohydric alcohol could be rational and promising access
to β-oxopropyl carbonate (Scheme 1d). Notably, this is a
thermodynamically feasible process supported by DFT study.[11]
Introduction
It is well known that organic carbonates are compounds of great
interest due to their application in pharmacology, agriculture,
and lithium ion batteries.[1] Notably, β-oxoalkyl carbonates as a
kind of functional dissymmetric carbonates, is commonly used
as reagents or intermediates in organic synthesis and polymer
chemistry.[2] For example, they can be used to synthesis (S)-
oxybutynin[3] or to prepare cyclopentenones.[4] However, toxic
reagent (e.g. chloroformate, Scheme 1a)[5] or pre-preparing
functionalized starting material (e.g. allylic carbonate, Scheme
1b) is required in conventional procedures.[6] From the viewpoint
of green chemistry and sustainable development, preparation of
β-oxopropyl
carbonates
from
readily
available
and
environmentally friendly materials could be a fascinating topic.
Carbon dioxide is an abundant, nontoxic, economical, and
renewable carbon source and therefore the utilization of CO2 as
advantageous C1 building block to prepare value-added
chemicals, e.g. organic carbonates, has gained increasing
attention over the past decades.[7] Unfortunately, few reactions
involving CO2 are thermodynamically feasible originating from
the thermodynamic stability and kinetic inertness of CO2.
Therefore, developing efficient catalysis for CO2 conversion
especially under mild conditions is extraordinary desirable and
remains a great challenge.[8]
Scheme 1. Synthetic access to β-oxoalkyl carbonates.
In view of mechanistic consideration, this three-component
reaction is a tandem process by integrating carboxylative
cyclization of propargylic alcohols with CO2 (step I) and the
transesterification of α-alkylidene cyclic carbonates with
monohydric alcohols (step II).[12] Accordingly, developing
effective catalyst system for both individual steps could be
crucial to performing such one-pot three-component tandem
reaction. Most recently, Costa et al reported guanidine-catalyzed
synthesis of carbonate and carbamate derivatives from
o
propargylic alcohols under supercritical CO2 conditions (100 C,
24 h).[12] In addition, β-oxopropyl carbonates were obtained from
propargylic alcohols and several external nucleophiles e.g.
MeOH, n-BuOH, and butan-2-ol using bicyclic guanidine as a
catalyst in supercritical CO2. Nevertheless, drawbacks such as
high reaction pressure and limited substrate scope were
exposed in this protocol. Therefore, developing effective
catalytic method to produce β-oxopropyl carbonates via the
three-component tandem reaction especially under mild
conditions is extremely challenging.
[a]
[b]
Z.-H. Zhou, Dr. Q.-W. Song, J.-N. Xie, R. Ma, Prof. Dr. L.-N. He
State Key Laboratory and Institute of Elemento-Organic Chemistry
Nankai University
Tianjin 300071 (P. R. China)
E-mail: heln@nankai.edu.cn
Prof. Dr. L.-N. He
Collaborative Innovation Center of Chemical Science and
Engineering
Nankai University
Tianjin 300071 (P. R. China)
Supporting information for this article is given via a link at the end of
the document.
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Basic silver compound with both Lewis acidic and Lewis basic
sites could be able to activate CO2, carbon-carbon triple bond,
and hydroxyl group.[13] Thus, we envisioned that basic silver
compound could serve as a versatile catalyst capable of
promoting the tandem reaction through the cooperative
oxopropyl carbonates (3da-3ha) in good yields. Benzyl alcohols
with methoxy at the m- and o-position on the aryl ring (1f-1g) did
not show obvious steric effect. Typically, heteroaromatic
alcohols such as pyridine-2-ylmethanol (1i) and thiophen-2-
ylmethanol (1j) were also effective substrates. Interestingly, allyl
activation of propargylic alcohols, CO2, and monohydric alcohols, alcohol (1k), generally giving α-alkoxy-α-methyl cyclic
thus enables the production of β-oxopropyl carbonates
effectively under mild conditions. Herein, we would like to
disclose an efficient silver(I)-catalyzed three-component tandem
reaction. As a result, β-oxopropyl carbonates were synthesized
with greatly enhanced yield together with broad substrate scope.
carbonates,[12] was exclusively conversed into the corresponding
allylic carbonate in this study. Besides, aliphatic alcohols bearing
with carbonyl group (1l) and diphenylmethanol (1m) also
showed good reactivity. In particular, the configuration of 3da
was unambiguously confirmed by a single-crystal X-ray analysis
(Figure 1).[14]
Results and Discussion
Table 1. Optimization of the reaction conditions.[a]
Initially, the three-component tandem reaction of benzyl alcohol
(1a), 2-methylbut-3-yn-2-ol (2a), and CO2 was chosen as the
model reaction to optimize the reaction conditions as
summarized in Table 1. The reaction did not occur without any
catalyst (entry 1). Several silver(I) salts, such as AgNO3, AgCl,
AgOAc, AgO2CCF3, AgOTf, and Ag2CO3 were examined in the
presence of PPh3 under 2 MPa CO2 at 60 oC for 12 h. As a
result, AgNO3 and AgCl showed no activity (entries 2 and 3).
Gratifyingly, AgOAc, AgO2CCF3, AgOTf, and Ag2CO3 promoted
the reaction to successfully afford benzyl-(2-methyl-3-oxobutan-
2-yl) carbonate (3aa) (entries 4-7). Notably, Ag2CO3 displayed
promising catalytic activity (entry 7), suggesting that basic silver
compounds could catalyze the three-component reaction.
Therefore, Ag2CO3 was selected as the catalyst for further
optimizing the reaction conditions.
The influence of reaction temperature on the reaction was
then explored. It was found that 3aa yield was raised with the
increase in reaction temperature (entry 8 vs. 7). Further
increasing the temperature to 120 oC, lower 3aa yield was
obtained (entry 9 vs. 8) and by-products such as 4-(benzyloxy)-
4,5,5-trimethyl-1,3-dioxolan-2-one (4a), dibenzyl carbonate(5a),
and 3-hydroxy-3-methylbutan-2-one (6a) were also detected by
GC-MS as illustrated in Scheme 2. Prolonging reaction time to
18 h at 80 oC gave the similar by-products (entry 10 vs. 9),
indicating high temperature and long reaction time may be
favorable for side reactions, e.g. the tautomerization of 3aa and
addition of benzyl alcohol to 4,4-dimethyl-5-methylene-1,3-
dioxolan-2-one (7a, Scheme 8) to produce 4a[12] and alcoholysis
of 3aa to from 5a and 6a. Tuning the molar ratio of 2a/1a to 1.5,
3aa yield improved apparently (entry 11). On the other hand, the
reaction performed well under 1 MPa CO2 (entry 12). Further
decreasing the pressure, 3aa yield was reduced obviously (entry
13 vs. 12). Notably, this protocol was also perform smoothly
even at atmospheric pressure of CO2 (entry 14).
Entry
Catalyst
T [oC]
P [MPa]
Conversion
[%][b]
Yield [%][b]
1
-
60
60
60
60
60
60
60
80
120
80
80
80
80
80
2
0
0
2
AgNO3
AgCl
2
0
0
3
2
0
0
4
AgOAc
AgO2CCF3
AgOTf
Ag2CO3
Ag2CO3
Ag2CO3
Ag2CO3
Ag2CO3
Ag2CO3
Ag2CO3
Ag2CO3
2
25
50
53
69
88
81
98
97
100
84
53
24
46
50
68
84
62
78
93
5
2
6
2
7
2
8
2
9
2
10[c]
11[d]
12[d]
13[d]
14[d]
2
2
1
98(91[e]
80
)
0.5
0.1
48
[a] Reaction conditions: 1a (108.1 mg, 1 mmol), 2a (84.1 mg, 1 mmol), Cat. (5
mol% relative to 1a) and PPh3 (26.2 mg, 0.1 mmol) in CH3CN (1 mL) for 12 h.
[b] Determined by GC analysis with biphenyl as the internal standard. [c] 18 h.
[d] 2a (126.2 mg, 1.5 mmol). [e] Isolated yield.
Subsequently, the substrate scope of this three-component
tandem reaction was investigated as displayed in Scheme 3.
Monohydric alcohols with different alkylene chain lengths (1a-
1c) were found to undergo the reaction efficiently. Among them,
3-phenylpropan-1-ol (1c) showed a relative low activity, probably
due to the steric hindrance. Several typical substituted benzyl
alcohols with electron-withdrawing or electron–donating
functional groups were compatible to afford the corresponding β-
Scheme 2. By-products in the model reaction.
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Scheme 3. Scope of monohydric alcohols. Reaction conditions: 1 (1 mmol),
2a (126.2 mg, 1.5 mmol), Ag2CO3 (13.8 mg, 0.05 mmol), PPh3 (26.2 mg, 0.1
mmol), CH3CN (1 mL), 1 MPa CO2, 80 oC, 12 h; isolated yields based on 1.
Scheme 4. Scope of propargylic alcohols. Reaction conditions: 1a (108.1 mg,
1 mmol), 2 (1.5 mmol), Ag2CO3 (13.8 mg, 0.05 mmol), PPh3 (26.2 mg, 0.1
mmol), CH3CN (1 mL), 1 MPa CO2, 80 oC, 18 h; yields of isolated products
based on 1a. [a] 12 h.
Scheme 5. Gram-scale experiment.
Figure 1. X-ray structure of compound 3da.
Although this three-component tandem reaction is assumed to
go through the carboxylative cyclization of propargylic alcohol
with CO2 and subsequent transesterification of α-alkylidene
cyclic carbonates with monohydric alcohol,[12] the stepwise
reactions were further examined to get shed some light on this
transformation as depicted in Scheme 6. 4,4-Dimethyl-5-
methylene-1,3-dioxolan-2-one (7a) was firstly formed from 2-
methylbut-3-yn-2-ol (2a) and CO2 in 73% yield. Subsequently,
benzyl alcohol (1a) was introduced into the resultant mixture
without the isolation of 7a. As a result, the corresponding
product 3aa was obtained in almost quantitative yield after 6 h.
Similarly, various propargylic alcohols were also subject to the
three-component tandem reaction under otherwise identical
reaction conditions in Scheme 4. Propargylic alcohols with a
variety of alkyl and aryl substituents at the propargylic position
were effective substrates to give the corresponding carbonates
(3aa-3ae) in excellent yields. Especially, β-oxopropyl allylic
carbonate (3af), a key intermediate in the Pd-catalyzed allylic
alkylation,[6] was successfully synthesized in 95% yield through
this protocol. Cyclopentyl- and cyclohexyl-substituted propargylic
alcohols also showed high reactivity, affording the desired
products (3ag-3ah) in 93% and 96% yields, respectively. In
addition, secondary alcohol also performed well (2i). However,
internal propargylic alcohols with a phenyl group at the terminal
position, did not give the target products (3aj-3ak) with full
recovery of starting materials, presumably because the
introduction of a phenyl group at the terminal position caused a
decrease in reactivity.[13a]
To further expand the applicability of this methodology, a
gram-scale experiment was carried out as demonstrated in
Scheme 5. To our delight, the tandem reaction of benzyl alcohol
(1a), 2-methylbut-3-yn-2-ol (2a), and CO2 was carried out
smoothly to give the desired product 3aa in 80% yield, thus
indicating this developed method is practical and readily
scalable.
Scheme 6. Stepwise synthesis of typical β-oxopropyl carbonate.
To gain deep insights into the role of silver catalysis, control
experiments were conducted towards the transesterification step.
As shown from the result in Scheme 7, the reaction of 1a and 7a
did not happen without any catalyst. Fortunately, silver(I)
catalyst rendered the reaction running smoothly to give 3aa in
moderate yield. The in situ generated basic silver complex from
Ag2CO3 and PPh3 has been reported to be a robust catalyst for
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the carboxylative cyclization of propargylic alcohol and CO2 to
form α-alkylidene cyclic carbonate.[13a] Therefore, Ag2CO3/PPh3
as versatile catalyst for both the carboxylative cyclization and
the transesterification of α-alkylidene cyclic carbonate with
monohydric alcohol was conceived as one of the most key
points to realize the three-component tandem reaction.
The substrate scope was broad and a variety of oxoalkyl
carbonates were exclusively obtained in high yields. In this work,
the basic silver compound acts as a versatile active catalyst for
both the carboxylation cyclization and the transesterification,
presumably through the cooperative activation of propargylic
alcohol, CO2, and monohydric alcohol. Notably, the current
approach was successfully carried out on gram-scale, which
provides practical application.
Experimental Section
General Procedure for the Synthesis of β-Oxopropyl Carbonates.
The synthesis of β-oxopropyl carbonates was conducted in a 25-mL
oven-dried autoclave with glass tube inside equipped with magnetic
stirring. The reactor was charged with Ag2CO3 (13.8 mg, 0.05 mmol),
PPh3 (26.2 mg, 0.1 mmol), propargylic alcohols (1.5 mmol), monohydric
alcohols (1 mmol), and CH3CN (1 mL). Then, CO2 was introduced into
Scheme 7. Control experiments.
On the basis of previous reports[2a,10b,10c,12] and experimental
results in this study, a plausible reaction mechanism is proposed
as illustrated in Scheme 8. Firstly, typical α-alkylidene cyclic
carbonate 7a is generated successively going through the
formation of the intermediate A and B via silver(I)-catalyzed
carboxylative cyclization of propargylic alcohol 2a with CO2.[13]
Subsequently, Ag2CO3/PPh3 promotes nucleophilic attack of
monohydric alcohol 1a at the carbonyl group of 7a to form
dissymmetrical acyclic carbonate intermediate C, which can be
then converted into the β-oxopropyl carbonate 3aa. On the other
hand, the tautomerization of 3aa and/or addition of benzyl
alcohol to unsaturated bond of 7a may occur to form α-alkoxy-α-
methyl cyclic carbonate 4a.[12] Moreover, further alcoholysis of
3aa gives dibenzyl carbonate 5a and α-hydroxyl ketone 6a.
o
the reactor and pressure was adjusted to 1 MPa at 80 C. The autoclave
was heated at this temperature for the desired time, and the pressure
was kept constant during the reaction. After the reaction was completed,
the reactor was cooled to room temperature and the excess of CO2 was
carefully vented. Then the reaction mixture was flushed with 3×5 mL
CH2Cl2 and removed under vacuum. The residue was purified by column
chromatography with petroleum ether/ethyl acetate as the eluent to afford
the desired product.
Benzyl (2-methyl-3-oxobutan-2-yl) carbonate (3aa). Yellow oil. IR
(KBr): 2989, 1742, 1722, 1457, 1384, 1284, 1156, 1124, 1028, 917 cm-1.
1H NMR (400 MHz, CDCl3) δ = 7.36 (d, J = 8.1 Hz, 5H), 5.16 (s, 2H),
2.13 (s, 3H), 1.51 (s, 6H) ppm. 13C NMR (101 MHz, CDCl3) δ = 206.42,
153.79, 134.95, 128.60, 128.58, 128.30, 85.72, 69.75, 23.43, 23.18 ppm.
GC-MS (EI, 70 eV) m/z (%) 91.10 (100), 77.10 (19.76), 79.10 (17.72),
108.10 (13.90), 69.10 (11.99), 65.05 (10.26), 107.10 (10.20), 92.10
(10.10).
2-Methyl-3-oxobutan-2-yl (3-phenethyl) carbonate (3ba). Colourless
oil. IR (KBr): 2989, 2960, 1743, 1725, 1498, 1456, 1388, 1358, 1285,
1156, 1123, 1099, 969, 915, 794, 751, 700 cm-1. 1H NMR (400 MHz,
CDCl3) δ = 7.34-7.28 (m, 2H), 7.27-7.21 (m, 3H), 4.36 (t, J = 7.1 Hz, 2H),
2.99 (t, J = 7.1 Hz, 2H), 2.11 (s, 3H), 1.49 (s, 6H) ppm. 13C NMR (101
MHz, CDCl3) δ = 206.62, 153.81, 136.93, 128.92, 128.57, 126.73, 85.54,
68.41, 35.14, 23.46, 23.19 ppm. HRMS (ESI): C14H19O4 for [M+H]+
calculated 251.1278, found 251.1283.
2-Methyl-3-oxobutan-2-yl (3-phenylpropyl) carbonate (3ca). Light
yellow oil. IR (KBr): 2988, 2943, 1743, 1726, 1455, 1390, 1358, 1285,
1156, 1124, 950, 794, 747, 701 cm-1. 1H NMR (400 MHz, CDCl3) δ = 7.29
(t, J = 7.4 Hz, 2H), 7.20 (t, J = 8.5 Hz, 3H), 4.15 (t, J = 6.5 Hz, 2H), 2.75-
2.69 (m, 2H), 2.18 (s, 3H), 2.01 (dt, J = 13.6, 6.6 Hz, 2H), 1.52 (s, 6H)
ppm. 13C NMR (101 MHz, CDCl3) δ = 206.59, 153.90, 140.78, 128.46,
128.35, 126.09, 85.44, 67.50, 31.81, 30.16, 23.54, 23.23 ppm. HRMS
(ESI): C15H21O4 for [M+H]+ calculated 265.1434, found 265.1438.
2-Methyl-3-oxobutan-2-yl (4-nitrobenzyl) carbonate (3da). Yellow
solid. M.p. 95-96 oC. IR (KBr): 3007, 2993, 2946, 2850, 1745, 1722, 1606,
1517, 1453, 1345, 1286, 1155, 1127, 981, 915, 856, 835, 791, 737 cm-1.
1H NMR (400 MHz, CDCl3) δ = 8.24 (d, J = 8.7 Hz, 2H), 7.55 (d, J = 8.6
Hz, 2H), 5.24 (s, 2H), 2.15 (s, 3H), 1.54 (s, 6H) ppm. 13C NMR (101 MHz,
CDCl3) δ = 206.02, 153.53, 147.89, 142.16, 128.37, 123.87, 86.16, 67.99,
23.73, 23.38 ppm. HRMS (ESI): C13H16NO6 for [M+H]+ calculated
282.0872, found 282.0970.
Scheme 8. Plausible reaction mechanism.
Conclusions
2-Methyl-3-oxobutan-2-yl p-tolyl carbonate (3ea). Yellow oil. IR (KBr):
2989, 2943, 1742, 1726, 1519, 1454, 1382, 1281, 1155, 1122, 919, 806
In summary, we have established an elegant protocol for
expeditious chemical utilization of CO2 to generate various β-
oxopropyl carbonates from commercial available propargylic
alcohols, CO2, and monohydric alcohols under mild conditions.
1
cm-1. H NMR (400 MHz, CDCl3) δ = 7.30-7.26 (m, 2H), 7.18 (d, J = 7.8
Hz, 2H), 5.12 (s, 2H), 2.35 (s, 3H), 2.13 (s, 3H), 1.51 (s, 6H) ppm. 13C
NMR (101 MHz, CDCl3) δ = 206.64, 153.81, 138.52, 131.90, 129.25,
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128.49, 85.65, 69.75, 23.47, 23.17, 21.18 ppm. HRMS (ESI): C14H19O4
for [M+H]+ calculated 251.1278, found 251.1278.
Benzyl 3-ethyl-3-methyl-4-oxopentanoate (3ab). Colourless oil. IR
(KBr): 2980, 2945, 1742, 1724, 1457, 1382, 1357, 1272, 1149, 1116, 965,
885, 793, 755, 737, 699 cm-1. 1H NMR (400 MHz, CDCl3) δ = 7.41-7.32
(m, 5H), 5.15 (d, J = 1.7 Hz, 2H), 2.12 (s, 3H), 1.92 (dq, J = 15.0, 7.5 Hz,
1H), 1.76 (dq, J = 14.9, 7.5 Hz, 1H), 1.52 (s, 3H), 0.89 (t, J = 7.5 Hz, 3H)
ppm. 13C NMR (101 MHz, CDCl3) δ = 206.70, 153.80, 134.98, 128.63,
128.61, 128.35, 88.47, 69.75, 29.48, 24.16, 19.48, 7.48 ppm. HRMS
(ESI): C14H19O4 for [M+H]+ calculated 251.1278, found 251.1281.
3-Methoxybenzyl (2-methyl-3-oxobutan-2-yl) carbonate (3fa). Yellow
oil. IR (KBr): 2990, 2944, 1743, 1726, 1602, 1492, 1461, 1383, 1281,
1156, 1123, 1052, 926, 854, 792 cm-1. 1H NMR (400 MHz, CDCl3) δ =
7.29 (d, J = 7.8 Hz, 1H), 6.96 (d, J = 7.6 Hz, 1H), 6.92 (s, 1H), 6.88 (dd, J
= 8.2, 2.1 Hz, 1H), 5.13 (s, 2H), 3.81 (s, 3H), 2.14 (s, 3H), 1.52 (s, 6H)
ppm. 13C NMR (101 MHz, CDCl3) δ = 206.56, 159.71, 153.77, 136.38,
129.67, 120.40, 114.27, 113.48, 85.74, 69.61, 55.21, 23.51, 23.18 ppm.
HRMS (ESI): C14H19O5 for [M+H]+ calculated 267.1227, found 267.1231.
2-Methoxybenzyl (2-methyl-3-oxobutan-2-yl) carbonate (3ga). Yellow
oil. IR (KBr): 2989, 2943, 1742, 1726, 1602, 1497, 1466, 1385, 1282,
1156, 1123, 920, 756 cm-1. 1H NMR (400 MHz, CDCl3) δ = 7.32 (dd, J =
13.1, 4.9 Hz, 2H), 6.97-6.86 (m, 2H), 5.23 (s, 2H), 3.84 (s, 3H), 2.15 (s,
3H), 1.51 (s, 6H) ppm. 13C NMR (101 MHz, CDCl3) δ = 206.82, 157.60,
153.90, 130.11, 129.99, 123.19, 120.36, 110.41, 85.59, 65.43, 55.36,
23.43, 23.19 ppm. HRMS (ESI): C14H19O5 for [M+H]+ calculated
267.1227, found 267.1225.
4-Bromobenzyl (2-methyl-3-oxobutan-2-yl) carbonate (3ha). Yellow
oil. IR (KBr): 2989, 2946, 1744, 1724, 1491, 1458, 1383, 1282, 1156,
1123, 1013, 919, 800, 698 cm-1. 1H NMR (400 MHz, CDCl3) δ = 7.51 (d, J
= 8.4 Hz, 2H), 7.28 (d, J = 3.1 Hz, 2H), 5.11 (s, 2H), 2.14 (s, 3H), 1.52 (s,
6H) ppm. 13C NMR (101 MHz, CDCl3) δ = 206.38, 153.68, 133.94,
131.79, 129.99, 122.76, 85.88, 68.89, 23.58, 23.22 ppm. HRMS (ESI):
C13H16BrO4 for [M+H]+ calculated 315.0226, found 315.0229.
2-Methyl-3-oxobutan-2-yl (pyridin-2-ylmethyl) carbonate (3ia). Brown
oil. IR (KBr): 2990, 2943, 1746, 1725, 1594, 1440, 1384, 1286, 1156,
1124, 1108, 949, 913, 789, 760, 698 cm-1. 1H NMR (400 MHz, CDCl3) δ =
8.60 (d, J = 4.5 Hz, 1H), 7.73 (t, J = 7.5 Hz, 1H), 7.39 (d, J = 7.8 Hz, 1H),
7.26 (dd, J = 7.8, 5.9 Hz, 1H), 5.28 (s, 2H), 2.19 (s, 3H), 1.55 (s, 6H) ppm.
13C NMR (101 MHz, CDCl3) δ = 206.47, 154.83, 153.69, 149.47, 136.85,
123.08, 121.50, 85.95, 69.77, 23.63, 23.22, ppm. HRMS (ESI):
C12H16NO4 for [M+H]+ calculated 238.1074, found 238.1072.
2-Methyl-3-oxobutan-2-yl (thiophen-2-ylmethyl) carbonate (3ja).
Brown oil. IR (KBr): 3736, 3565, 3473, 3417, 2989, 2959, 1742, 1725,
1641, 1618, 1456, 1384, 1360, 1279, 1156, 1123, 917, 794, 745, 701 cm-
1. 1H NMR (400 MHz, CDCl3) δ = 7.34 (dd, J = 5.1, 1.0 Hz, 1H), 7.14 (d, J
= 3.4 Hz, 1H), 6.99 (dd, J = 5.1, 3.5 Hz, 1H), 5.30 (s, 2H), 2.14 (s, 3H),
1.51 (s, 6H) ppm. 13C NMR (101 MHz, CDCl3) δ = 206.55, 153.63, 136.58,
129.00, 127.48, 126.88, 85.95, 63.79, 23.50, 23.16 ppm. HRMS (ESI):
C11H14O4SNa for [M+Na]+ calculated 265.0505, found 265.0501.
Benzyl (3,5-dimethyl-2-oxohexan-3-yl) carbonate (3ac). Light yellow
oil. IR (KBr): 2959, 2873, 1743, 1724, 1457, 1382, 1284, 1268, 1153,
1
1127, 912, 792, 738, 698 cm-1. H NMR (400 MHz, CDCl3) δ = 7.43-7.30
(m, 5H), 5.19-5.10 (m, 2H), 2.13 (s, 3H), 1.81-1.69 (m, 3H), 1.55 (s, 3H),
0.91 (t, J = 5.9 Hz, 6H) ppm. 13C NMR (101 MHz, CDCl3) δ = 206.95,
153.75, 135.07, 128.59, 128.35, 88.61, 69.64, 44.18, 24.34, 24.17, 23.78,
23.67, 20.65 ppm. HRMS (ESI): C16H26NO4 for [M+NH4]+ calculated
296.1856, found 296.1842.
Benzyl (3-methyl-2-oxononan-3-yl) carbonate (3ad). Yellow oil. IR
(KBr): 2955, 2930, 2859, 1743, 1725, 1457, 1381, 1356, 1277, 1176,
1152, 1124, 915, 793, 737, 698 cm-1. 1H NMR (400 MHz, CDCl3) δ =
7.42-7.31 (m, 5H), 5.19-5.11 (m, 2H), 2.12 (s, 3H), 1.89-1.65 (m, 2H),
1.53 (s, 3H), 1.25 (s, 8H), 0.86 (t, J = 6.7 Hz, 3H) ppm. 13C NMR (101
MHz, CDCl3) δ = 206.82, 153.79, 135.00, 128.63, 128.60, 128.37, 88.27,
69.73, 36.57, 31.51, 29.32, 24.19, 22.97, 22.49, 20.06, 14.01 ppm.
HRMS (ESI): C18H27O4 for [M+H]+ calculated 307.1904, found 307.1910.
Benzyl (3-oxo-2-phenylbutan-2-yl) carbonate (3ae). Yellow oil. IR
(KBr): 3064, 3034, 3008, 2945, 1745, 1722, 1601, 1584, 1496, 1451,
1381, 1356, 1277, 1239, 1216, 1133, 1104, 1059, 1030, 891, 791, 764,
1
700 cm-1. H NMR (400 MHz, CDCl3) δ = 7.49-7.29 (m, 10H), 5.30-5.19
(m, 2H), 1.98 (s, 3H), 1.91 (s, 3H) ppm. 13C NMR (101 MHz, CDCl3) δ =
207.07, 153.82, 135.03, 128.61, 128.30, 87.24, 69.76, 30.68, 24.90,
23.57, 20.99 ppm. HRMS (ESI): C18H19O4 for [M+H]+ calculated
299.1278, found 299.1280.
Benzyl (3-methyl-4-oxopent-1-en-3-yl) carbonate (3af). Light yellow oil.
IR (KBr): 3092, 3066, 3034, 2993, 2945, 1745, 1727, 1455, 1382, 1276,
1180, 1104, 937, 908, 792, 737, 698 cm-1. 1H NMR (400 MHz, CDCl3) δ =
7.43-7.31 (m, 5H), 6.00 (dd, J = 17.4, 10.9 Hz, 1H), 5.43 (d, J = 17.4 Hz,
1H), 5.30 (d, J = 11.0 Hz, 1H), 5.17 (d, J = 1.4 Hz, 2H), 2.10 (s, 3H), 1.62
(s, 3H) ppm. 13C NMR (101 MHz, CDCl3) δ = 203.99, 153.67, 135.63,
134.84, 128.71, 128.64, 128.40, 117.06, 87.70, 69.98, 23.62, 21.12 ppm.
GC-MS (EI, 70 eV) m/z (%) 91.10 (100), 77.05 (25.91), 79.10 (24.80),
96.10 (22.80), 108.10 (17.30), 67.10 (13.80), 65.05 (13.74), 92.10
(13.67), 107.10 (13.03), 71.10 (11.63), 105.10 (10.92).
Benzyl (3-cyclopentyl-2-oxopropan-3-yl) carbonate (3ag). Light
yellow oil. IR (KBr): 2962, 2875, 1742, 1722, 1499, 1454, 1383, 1358,
1277, 1176, 971, 947, 793, 738, 699 cm-1. 1H NMR (400 MHz, CDCl3) δ =
7.41-7.33 (m, 5H), 5.16 (s, 2H), 2.22-2.14 (m, 2H), 2.12 (s, 3H), 2.00-
1.92 (m, 2H), 1.85-1.66 (m, 4H) ppm. 13C NMR (101 MHz, CDCl3) δ =
205.62, 154.31, 134.90, 128.68, 128.63, 128.40, 95.97, 69.90, 35.62,
24.88, 24.45 ppm. HRMS (ESI): C15H19O4 for [M+H]+ calculated
263.1278, found 263.1284.
Benzyl (3-cyclohexyl-2-oxopropan-3-yl) carbonate (3ah). Colourless
oil. IR (KBr): 2940, 2863, 1742, 1720, 1452, 1383, 1354, 1295, 1272,
1246, 1138, 931, 793, 736, 698 cm-1. 1H NMR (400 MHz, CDCl3) δ =
7.42-7.32 (m, 5H), 5.16 (s, 2H), 2.09 (s, 3H), 2.06 (s, 1H), 1.72-1.51 (m,
8H), 1.31-1.20 (m, 1H) ppm. 13C NMR (101 MHz, CDCl3) δ = 207.07,
153.82, 135.03, 128.61, 128.30, 87.24, 69.76, 30.68, 24.90, 23.57, 20.99
ppm. HRMS (ESI): C16H21O4 for [M+H]+ calculated 277.1434, found
277.1439.
Benzyl (2-oxooctan-3-yl) carbonate (3ai). Light yellow oil. IR (KBr):
2957, 2931, 2862, 1749, 1744, 1499, 1457, 1388, 1267, 1121, 948, 910,
788, 751, 738, 698 cm-1. 1H NMR (400 MHz, CDCl3) δ = 7.42-7.32 (m,
5H), 5.19 (s, 2H), 4.90 (dd, J = 7.8, 4.9 Hz, 1H), 2.16 (s, 3H), 1.82-1.69
(m, 2H), 1.44-1.35 (m, 2H), 1.30 (dd, J = 10.0, 5.1 Hz, 4H), 0.87 (t, J =
6.8 Hz, 3H) ppm. 13C NMR (101 MHz, CDCl3) δ = 205.19, 154.76, 134.86,
128.61, 128.59, 128.30, 81.93, 70.02, 31.30, 30.39, 25.88, 24.60, 22.31,
Allyl (2-methyl-3-oxobutan-2-yl) carbonate (3ka). Light yellow oil. IR
(KBr): 2990, 2945, 1745, 1726, 1367, 1296, 1280, 1156, 1122, 967, 952,
1
857, 793 cm-1. H NMR (400 MHz, CDCl3) δ = 5.93 (ddd, J = 16.3, 11.0,
5.8 Hz, 1H), 5.37 (d, J = 17.2 Hz, 1H), 5.29 (d, J = 10.4 Hz, 1H), 4.62 (d,
J = 5.8 Hz, 2H), 2.17 (s, 3H), 1.52 (s, 6H) ppm. 13C NMR (101 MHz,
CDCl3) δ = 206.59, 153.65, 131.23, 119.26, 85.65, 68.59, 23.57, 23.22
ppm. GC-MS (EI, 70 eV) m/z (%) 99.10 (100), 69.05 (96.61), 85.10
(78.02), 84.10 (73.55), 86.10 (28.62), 143.15 (27.67), 71.05 (16.62).
2-Methyl-3-oxobutan-2-yl (2-oxopropyl) carbonate (3la). Yellow oil. IR
(KBr): 2992, 2943, 1748, 1424, 1371, 1289, 1183, 1158, 1114, 957, 918,
789, 699 cm-1. 1H NMR (400 MHz, CDCl3) δ = 4.67 (s, 2H), 2.22 (s, 3H),
2.17 (s, 3H), 1.53 (s, 6H) ppm. 13C NMR (101 MHz, CDCl3) δ = 206.51,
200.57, 153.45, 86.45, 70.76, 25.82, 23.57, 23.13 ppm. GC-MS (EI, 70
eV) m/z (%) 101.05 (100), 69.05 (58.73), 85.10 (44.89), 84.10 (38.49),
159.10 (31.41).
Benzhydryl (2-methyl-3-oxobutan-2-yl) carbonate (3ma). White solid.
Melting point: 49-50 oC. IR (KBr): 3064, 3033, 2988, 2939, 1807, 1744,
1496, 1455, 1385, 1358, 1282, 1265, 1155, 1122, 1085, 970, 915, 747,
700 cm-1. 1H NMR (400 MHz, CDCl3) δ = 7.41-7.28 (m, 10H), 6.68 (s, 1H),
2.03 (s, 3H), 1.50 (s, 6H) ppm. 13C NMR (101 MHz, CDCl3) δ = 206.53,
153.27, 143.80, 139.30, 128.55, 128.45, 128.20, 127.51, 126.92, 126.50,
85.94, 81.12, 23.25, 23.17 ppm. HRMS (ESI): C19H20O4Na for [M+Na]+
calculated 335.1254, found 335.1261.
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13.90 ppm. HRMS (ESI): C16H23O4 for [M+H]+ calculated 279.1591,
found 279.1591.
[2]
For examples, see: a) J. M. Joumier, C. Bruneau, P. H. Dixneuf, Synlett
1992, 1992, 453-454; b) S. Ogoshi, T. Morimoto, K. Nishi, K. Ohe, S.
Murai, J. Org. Chem. 1993, 58, 9-10; c) C. W. Michael, A. C. Gary, P. J.
Matthew, Synlett 2004, 1195-1198; d) N. E. Stainforth, G. A. Cutting, M.
P. John, M. C. Willis, Tetrahedron: Asymmetry 2009, 20, 741-743.
B. M. Trost, J. Xu, M. Reichle, J. Am. Chem. Soc. 2007, 129, 282-283.
N. Sun, M. Chen, Y. Liu, J. Org. Chem. 2014, 79, 4055-4067.
P. F. De Cusati, R. A. Olofson, Tetrahedron Lett. 1990, 31, 1405-1408.
T. Hosokawa, S. Aoki, M. Takano, T. Nakahira, Y. Yoshida, S.-I.
Murahashi, J. Chem. Soc. Chem. Commun. 1991, 1559-1560.
a) Carbon Dioxide as a Chemical Feedstock, (ed.: M. Aresta), Wiley-
VCH, Weinheim, 2010; b) A.-H. Liu, Y.-N. Li, L.-N. He, Pure Appl.
Chem. 2012, 84, 581-602.
4-(Benzyloxy)-4,5,5-trimethyl-1,3-dioxolan-2-one (4a). Light yellow
solid. Melting point: 68-69 oC. IR (KBr): 2935, 1805, 1744, 1457, 1386,
1268, 1157, 1122, 997, 920, 790, 752, 741, 699 cm-1. 1H NMR (400 MHz,
CDCl3) δ = 7.34 (dd, J = 15.3, 8.9 Hz, 5H), 4.80 (d, J = 11.4 Hz, 1H), 4.68
(d, J = 11.4 Hz, 1H), 1.62 (s, 3H), 1.47 (d, J = 21.0 Hz, 6H) ppm. 13C
NMR (101 MHz, CDCl3) δ = 153.07, 137.05, 128.47, 127.81, 127.19,
108.16, 87.76, 65.35, 24.34, 20.29, 16.46 ppm. HRMS (ESI): C13H17O4
for [M+H]+ calculated 237.1121, found 237.1123.
Dibenzyl carbonate (5a). Colorless oil. IR (KBr): 3066, 3035, 2959,
1747, 1499, 1456, 1392, 1370, 1264, 949, 911, 789, 749, 697 cm-1. 1H
NMR (400 MHz, CDCl3) δ = 7.33-7.25 (m, 10H), 5.10 (s, 4H) ppm. 13C
NMR (101 MHz, CDCl3) δ = 155.07, 135.15, 128.57, 128.52, 128.32,
69.72 ppm. GC-MS (EI, 70 eV) m/z (%) 91.10 (100), 92.10 (77.76), 79.10
(39.29), 77.10 (37.94), 107.10 (34.27), 65.05 (25.23), 105.10 (17.56),
106.10 (15.92).
[3]
[4]
[5]
[6]
[7]
[8]
Selected reviews for CO2 conversion, see: a) A. Goeppert, M. Czaun,
J.-P. Jones, G. K. Surya Prakash, G. A. Olah, Chem. Soc. Rev. 2014,
43, 7995-8048; b) M. Aresta, A. Dibenedetto, A. Angelini, Chem. Rev.
2014, 114, 1709-1742; c) Z.-Z. Yang, L.-N. He, J. Gao, A.-H. Liu, B. Yu,
Energy Environ. Sci. 2012, 5, 6602-6639; d) M. He, Y. Sun, B. Han,
Angew. Chem. Int. Ed. 2013, 52, 9620-9633; Angew. Chem. 2013, 125,
9798-9812; e) C. Maeda, Y. Miyazaki, T. Ema, Catal. Sci. Technol.
2014, 4, 1482-1497; f) Q. Liu, L. Wu, R. Jackstell, M. Beller, Nat.
Commun. 2015, 6, 5933.
3-Hydroxy-3-methylbutan-2-one (6a). Colorless oil. IR (KBr): 3516,
3415, 2983, 2936, 1726, 1363, 1179, 973, 962, 766, 746 cm-1. 1H NMR
(400 MHz, DMSO-d6) δ = 5.24 (s, 1H), 2.15 (s, 3H), 1.17 (s, 6H) ppm. 13
C
NMR (100.6 MHz, DMSO-d6) δ = 213.87, 75.75, 26.19, 24.26 ppm. GC-
MS (EI, 70 eV) m/z (%) 102.10 (8.57), 87.10 (100), 69.05 (61.60), 60.05
(92.12).
4,4-Dimethyl-5-methylene-1,3-dioxolan-2-one (7a). Colourless oil. IR
(KBr): 2990, 1875, 1824, 1743, 1725, 1686, 1383, 1269, 1172, 1084,
1030, 851, 767, 745 cm-1. 1H NMR (400 MHz, CDCl3) δ = 4.76 (d, J = 3.9
Hz, 1H), 4.31 (d, J = 3.9 Hz, 1H), 1.61 (s, 6H) ppm. 13C NMR (100.6 MHz,
CDCl3) δ = 158.70, 151.26, 85.28, 84.60, 27.56 ppm. GC-MS (EI, 70 eV)
m/z (%) 128.10 (2.81), 85.10 (6.49), 84.10 (100), 83.10 (3.54), 69.10
(48.16).
[9]
For typical reports on the carboxylative cyclization of propargylic
alcohols with CO2, see: a) Y. Gu, F. Shi, Y. Deng, J. Org. Chem. 2004,
69, 391-394; b) W. Yamada, Y. Sugawara, H. M. Cheng, T. Ikeno, T.
Yamada, Eur. J. Org. Chem. 2007, 2007, 2604-2607; c) Y. Kayaki, M.
Yamamoto, T. Ikariya, Angew. Chem. Int. Ed. 2009, 48, 4194-4197;
Angew. Chem. 2009, 121, 4258-4261; d) X. Tang, C. Qi, H. He, H.
Jiang, Y. Ren, G. Yuan, Adv. Synth. Catal. 2013, 355, 2019-2028; e)
Y.-B. Wang, D.-S. Sun, H.-Zhou, W.-Z. Zhang, X.-B. Lu, Green Chem.
2014, 16, 2266-2272; f) J. Hu, J. Ma, Q. Zhu, Q. Qian, H. Han, Q. Mei,
B. Han, Green Chem. 2016, 18, 382-385.
[10] a) J. Fournier, C. Bruneau, P. H. Dixneuf, Tetrahedron Lett. 1989, 30,
3981-3982; b) J. M. Joumier, J. Fournier, C. Bruneau, P. H. Dixneuf, J.
Chem. Soc. Perkin Trans. 1 1991, 3271-3274; c) J. M. Joumier, C.
Bruneau, P. H. Dixneuf, J. Chem. Soc. Perkin Trans. 1 1993, 1749-
1751; d) P. Toullec, A. C. Martin, M. Gio-Batta, C. Bruneau, P. H.
Dixneuf, Tetrahedron Lett. 2000, 41, 5527-5531.
Acknowledgements
We are grateful to the National Natural Science Foundation of
China, the Natural Science Foundation of Tianjin Municipality,
the Specialized Research Fund for the Doctoral Program of
Higher Education (20130031110013), the MOE Innovation Team
(IRT13022) of China, and the “111” Project of Ministry of
Education of China (project No. B06005) for financial support.
[11] Thermodynamically favorable reaction: ΔrH (298.15 K, in vacuo) = -
56.80 kcal/mol, ΔrG (298.15 K, in vacuo) = -36.20 kcal/mol, for the
detailed calculation, see supporting information Table S1.
Keywords: carbon dioxide utilization • multicomponent reaction
• β-oxopropyl carbonate • silver • synthetic methods
[12] N. Della Ca, B. Gabriele, G. Ruffolo, L. Veltri, T. Zanetta, M. Costa, Adv.
Synth. Catal. 2011, 353, 133-146.
[13] a) Q.-W. Song, W.-Q. Chen, R. Ma, A. Yu, Q.-Y. Li, Y. Chang, L.-N. He,
ChemSusChem 2015, 8, 821-847; b) Q.-W Song, Z.-H. Zhou, H.-Yin,
L.-N. He, ChemSusChem 2015, 8, 3967-3972.
[1]
a) S. Huang, B. Yan, S. Wang, X. Ma, Chem. Soc. Rev. 2015, 44,
3079-3116; b) X. B. Lu, D. J. Darensbourg, Chem. Soc. Rev. 2012, 41,
1462-1484; c) T. Sakakura, K. Kohno, Chem. Commun. 2009, 1312-
1330; d) V. Besse, F. Camara, C. Voirin, R. Auvergne, S. Caillol, B.
Boutevin, Polym. Chem. 2013, 4, 4545-4561; e) H. Zhang, H.-B. Liu, J.-
M. Yue, Chem. Rev. 2014, 114, 883-898; f) N. Kielland, C. J. Whiteoak,
A. W. Kleij, Adv. Synth. Catal. 2013, 355, 2115-2138.
[14] CCDC 1450783 (3da) contains the supplementary crystallographic data
for this paper. These data can be obtained free of charge from The
Cambridge Crystallographic Data Centre via www.ccdc.cam.
ac.uk/data_request/cif.
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Z.-H. Zhou, Q.-W. Song, J.-N. Xie, R.
Ma, L.-N. He*
Page No. – Page No.
Silver(I)-Catalyzed Three-Component
Reaction of Propargylic Alcohols,
CO2 and Monohydric Alcohols:
Thermodynamically Feasible Access
to β-Oxopropyl Carbonates
Basic silver compound with both Lewis acidic and Lewis basic sites could be able to
activate CO2, carbon-carbon triple bond and hydroxyl group and therefore serves
as a versatile catalyst for three-component reaction of propargylic alcohols, CO2,
and monohydric alcohols to exclusively produce β-oxopropyl carbonates under mild
conditions.
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