2-Oxo-Driven Coupling Reactions of 2-Oxo Aldehydes/2-Oxo Iminium Ions and Hydroperoxides at Room Temperature

Article abstract of DOI:10.1002/ejoc.201600795

An efficient 2-oxo-group-promoted direct coupling reaction between 2-oxo aldehydes and hydroperoxides has been developed. The method has been used successfully for the generation of different 2-oxo esters and acids. This reaction harnesses the hydrogen-bonding-induced self-decomposition tendency of hydroperoxides; the intermediates produced by this process then attack the aldehyde or iminium ion to generate cross-coupled products either by direct coupling or by an amine-catalysed pathway. No external oxidants or metal catalysts are required for our method, and the reaction takes place at room temperature.

Full text of DOI:10.1002/ejoc.201600795

A Journal of
Accepted Article
Title: 2-Oxo Driven Coupling Reaction of 2-oxoaldehydes/2-oxoiminium ions and hy-
droperoxides at Room Temperature
Authors: Shahnawaz Khan; Qazi Naveed Ahmed
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To be cited as: Eur. J. Org. Chem. 10.1002/ejoc.201600795
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European Journal of Organic Chemistry
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2-Oxo Driven Coupling Reaction of 2-oxoaldehydes/2-oxoiminium
ions and hydroperoxides at Room Temperature
Shahnawaz khan,[a][b] and Qazi Naveed Ahmed * [a][b]
Abstract: An efficient 2-oxo group promoted direct coupling method
between 2-oxoaldehydes and hydroperoxides has been developed
and applied successfully for the generation of different 2-oxoesters
and acids. This reaction impersonates hydrogen bonding induced
self-decomposition tendency of hydroperoxides that later attacks
aldehyde or iminium ion to generate cross-coupled products in a
direct coupling or amino catalytic pathway. As an advantage, no
external oxidants or metal catalysts are required in our method and
the reaction is admissible at the room temperature.
Introduction
Hydroperoxides, because of their excellent reactivity and
oxidative potential have found multiple applications in organic
synthesis.1 The characteristic feature of peroxide molecules is
due to relatively weak oxygen-oxygen linkage. The labile nature
of -O-O- bond is perhaps a consequence of the electronic and
molecular structure of peroxide molecules and because of the
relatively high electronegative feature of the oxygen atoms.
Virtually most of the traits of peroxide reactivity are allied with
the tendency for spontaneous change to form more stable
Scheme 1. Summary of this work.
products.2As a class, peroxides are exceptionally prone to
violent decomposition initiated by several mechanisms including
heat, light, catalysts and/or promoters. Using different promoters,
Traditionally, reaction of TBHP with aldehydes required Bu4NI or
the reactivity of hydro peroxides previously has been exploited in
Cu2Cl2 for the generation of tert-butyl benzoperoxoates and tert-
various directions as depicted in Scheme 1a.3 However,
butyl benzoates respectively.4 As evident, aldehyde group when
reactivity against a system having hydrogen bonding facilitator
reacted with TBHP in water (hydrogen bond donor) is incapable
group and an adjacent electrophilic site has never been
of generating reaction in absence of catalysts. In another
addressed. Therefore, in the present work (Scheme 1b), we
method reported on dehydrogenative cross-coupling of
addressed the following questions. (i) Can 2-oxo group in 2-
aldehydes with amines, aldehydes when treated with amines
and TBHP in presence of base or TBAI generated amides.5
oxoaldehydes (OA) promote the self-decomposition of hydro
peroxides to produce radicals that attack CHO group to generate
Despite plenty of research on organoperoxide promoted free
radical cross coupling reactions on aldehydes,6 there is no report
esters/ acid through direct coupling pathway at room
temperature under metal-free condition? (ii) If so, is the
production of radicals dependent or independent of the adjacent
aldehydes in direct coupling/ amino catalytic pathway under
electrophilic site? (iii) And what will be the effect on the reaction
on 2-oxo driven cross-coupling reaction of hydroperoxides with
metal free conditions at room temperature.
if we proceed through amino catalytic pathway?
Results and Discussion
In preceding efforts, our group tried to reveal the unprecedented
[a]
[b]
Shahnawaz khan, Qazi Naveed Ahmed
Medicinal chemistry division
Indian Institute of intehrative medicine (CSIR)
cannal road jammu. India. 180001
E-mail: naqazi@ac.in
Shahnawaz khan, Qazi Naveed Ahmed
Acsir.Indian Institute of intehrative medicine
cannal road jammu. India. 180001
E-mail: naqazi@ac.in
role of 2-oxo group towards the generation of different exigent
structures.7 In continuation, we focused our attentions towards
the study of divergence behaviour in reactivity of different hydro
peroxides against 2-oxoaldehydes. For this, we commenced our
study with the reaction of phenylglyoxal 1a (1 equiv) and TBHP
2a (1 equiv) in toluene at room temperature. To our surprise, we
isolated self catalyzed cross-coupled ester product 3aa in 15%
yield within 4 h (Table 1, entry 1). Subsequently, we observed
better yields of 3aa when stirred for 48 h (entry 2). Next, various
concentrations of TBHP were screened as shown in Table 1
(entries 3-6). Interestingly, reaction with 2 equiv of
Home page: http://www.iiim.res.in/People/CV/cv_naveed.php
Supporting information for this article is given via a link at the end of
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European Journal of Organic Chemistry
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Table 1. Optimization of the reactiona
conditions were eventually identified as 1a (1 equiv), 2a (2
equiv) in 1 mL of toluene at room temperature for 48 h.
Following these optimized procedure, three different sets of
experiments were carried out to scrutinize the scope and
limitations of this method. In one set of experiments, reaction
was performed between different 2-oxoaldehydes 1 and TBHP
2a (entries 3aa−3ai, Table 2). It was examined that substituents
at different positions of the arene group and their electronic
nature do not affect the efficiency of the reaction towards the
generation of 2- oxoester 3. In parallel, we performed another
set of reactions between 1 and hydrogen peroxides 2b (entries
4a-4f). As evident, reactions with hydrogen peroxide generated
different acids in good yields despite variation in substitution.
Along with few reactions were tested with cumene-peroxide as
well (entries 3ba-3bc). However, this set of reactions failed to
produce desired product even if tried for days (entries 3ba−3bc).
As evident, these reactions in general successfully generated
esters/acids in moderate to good yields under direct coupling
pathway at room temperature. Further the effect of secondary
entry
1c
2
solvent
toluene
toluene
toluene
toluene
toluene
toluene
MeOH
EtOH
2a (equiv)
1.0
yields (%)b
15
1.0
54
3
1.3
58
4
1.6
65
5
2.0
72
6
2.5
73
7
2.0
NR
8
2.0
Traces
NR
Table 3. Optimization of the reactiona
9
CHCl3
CH2Cl2
THF
2.0
10
11
2.0
NR
2.0
NR
a Reaction condition: 2-oxoaldehyde 1a (1 equiv) and TBHP 2a (2 equiv) in
b
c
toluene (1 mL) at rt (25-30 °C), reaction time 48 h. Isolated yields.
entry
1
2a (equiv)
1.0
amine (equiv)
5a (0.1)
5a (0.2)
5a (0.3)
5a (0.2)
5a (0.2)
5a (0.2)
5b (0.2)
5c (0.2)
5d (0.2)
yields (%)b
reaction time 4h. NR= no reaction.
38
52
51
69
92
89
78
75
40
TBHP gave improved yields of desired product when stirred for
48 h (entry 5). Furthermore, we studied the effect of the change
in the solvent on reaction yields (entries 7-11). As depicted,
most of the solvents due to participation in either solvent cage
effect8 or H-bonding failed to generate desired product. After
investigating various reaction parameters, the optimized reaction
2
1.0
3
1.0
4
1.1
5
1.2
Table 2. Scope of the ester synthesisa.
6
1.3
7c
8d
9e
a
1.2
1.2
1.2
a
Reaction condition: 2-oxoaldehyde 1a (1 equiv), TBHP 2a (1.2 equiv)
°
b
3aa (72%)
3ab(60%)
3ae (65%)
3ac (62%)
3af (65%)
and pyrrolidine 5a (0.2 equiv) in toluene (1 mL) at rt (25-30 C),for 2 h.
Isolated yields. cmorpholine 5b. d Piperidine 5c, e diethyl amine 5d.
amine 5 was investigated in the reaction of Phenylglyoxal 1a
and TBHP 2a in toluene at room temperature (Table 3). First,
different concentrations of pyrrolidine 5a were tested against
reaction between 1a (1 equiv) and TBHP (1 equiv) in 1 mL
toluene at room temperature (entries 1-3). Surprisingly, addition
of 0.1equiv pyrrolidine provided 3aa in 38% yield within 2 h
(entry 1). The same reaction with 0.2 equiv of 5a further
increased the yield to 52% (entry 2). However, there was no
predominant effect on yields when the concentration of 5a was
further increased (entry 3). The results demonstrate that the
reaction in amino catalytic pathway can significantly influence
the yields and the reactivity. Furthermore, different
concentrations of TBHP were investigated (entries 4-6). As
evident, reaction with 1.2 equiv TBHP gave the best yields for
the ester 3aa (entry 5, 92% yield). Efforts were then attempted
to check reactivity against different secondary amines, but the
product yields were not so good (<80% yield). After the thorough
3ad (68%)
3ag (63%)
*4a (75%)
3ah (70%)
*4b (78%)
3ai (68%)
*4c (73%)
*4d (69%)
*4f (68%)
*3bc NR
*4e (70%)
*3ba NR
*3bb NR
a Reaction condition: 2-oxoaldehyde 1a (1 equiv)and 2a TBHP/ 2b hydrogen
peroxide/ 2c cumene hydrogen peroxide (2 equiv) in toluene(1 mL) at rt (25-
30 °C), reaction time 48 h * reaction with H2O2.
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European Journal of Organic Chemistry
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Table 4. Scope of the ester synthesisa
3aa (92%)
3ab (94%)
3ac (93%)
3af (91%)
3ad (91%)
3ag (90%)
3ae (90%)
3ah (88%)
3ak (89%)
3ai (89%)
3al (91%)
3bc (91%)
3aj (93%)
3ba (89%)
3bb (92%)
3be (86%)
3bd (85%)
3bg (87%)
3bf (83%)
3bi (88%)
*4a (95%)
3bh (91%)
3bk (84%)
Figure 1. Control experiments.
3bj (88%)
executed between several OAs 1 and hydrogen peroxide
(entries 4a−4j). In this case as well, yields were good for all the
reactions conducted. In all reactions tested, we found that
reactions in amino catalytic pathway had better yields and
generated the desired product within 2 h.
*4f (93%)
*4c (91%)
*4d (93%)
*4e (90%)
*4b (93%)
In order to probe the mechanism of our method, we performed a
few controlled experiments (Figure 1). Experiment 1 and 2,
conducted between 1a (1 equiv) with 2a/2b (1.2 equiv) in
presence TEMPO in 1 mL toluene, failed to generate any
reaction, proving the free radical nature of our reaction. Similarly,
in experiment 3, the generation of benzoic acid 4a in trace
amounts highlighted that it may be through free radical pathway
as well. In experiment 4, we observed no product with simple
aldehydes (benzaldehyde). This experiment pointed toward the
immense role of the 2-oxo group in catalyzing the reaction. In
experiment 5, compound 7a was found unreacted when
experimented against our reaction conditions. This finding
undoubtedly rules out the pathway through 2-oxo acid. As
presumed in experiment 6, compound 3aa was generated in
very low yields when the reaction was administered in EtOH.
This obviously highlighted the role of H-bonding interactions in
promoting -O-O- bond cleavage. In fact, due to H-bonding there
exists a balance of charge between the two peroxy oxygen
atoms, resulting in homolytic cleavage. In addition, the failure of
experiment 7 to undergo deformylation reaction rules of out the
participation through 8a. Finally, in experiment 8, the reaction
with 2-acetyl benzaldehyde under optimized conditions justifies
that the production of radicals is dependent on the adjacent ele-
*4g (96%)
Reaction condition: 2-oxoaldehyde 1a (1 equiv), pyrrolidine 5a (0.2 equiv)
*4h (94%)
*4i (93%)
*4j (90%)
a
a
and TBHP 2a/ H2O2 2b/ cumene hydro peroxide 2c (1.2 equiv) in toluene (1
mL) at rt, for 2 h. b Isolated yields * reaction with H2O2.
optimization, we perceived that the best conditions for the
reaction were when 1 equiv of 1a was treated with 1.2 equiv Of
2a and 20 mol% of 5a in 1 mL of toluene at rt (entry 9). Having
discerned that pyrrolidine catalyzed the unprecedented Addition
of TBHP 2a with 2-oxoaldehyde 1a under the above optimized
conditions in high yields within 2 h, we then decided to
investigate the substrate scope of this method. As compiled in
Table 4, a variety of OAs 1 were tested against different
commercial hydroperoxides
2 (entries 3aa−4j). We were
delighted to observe that in all reactions tested, the desired
products 3/4 were produced in good yields (83−96%). In general,
we listed these reactions in two different sets of experiments. In
one set, different reactions were carried out between different 2-
oxoaldehydes 1 and organic hydroperoxides (TBHP or cumene
peroxide, entries 3aa−3bk). It was observed that both electron-
rich and electron-deficient OA could be smoothly transformed
Into the desired product. In addition, various experiments were
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European Journal of Organic Chemistry
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FULL PAPER
ctrophilic site. It could be an explaination for the promotion of our
reaction due to the improved electrophilicity of CHO group by
homolytic cleavage to 2-oxoaldehyde and free radicals. These
radicals finally lead to C-C bond cleavage to desired product 4.
Conclusions
In conclusion, we have developed additive free direct coupling
method
between
2-oxoaldehydes/2-oxoiminium
and
hydroperoxides at room temperature and applied successfully
for the generation of different 2-oxoesters and acids. Further
application on systems possessing different electrophilic sites in
conjugation to 2-oxo group is in progress.
Experimental Section
General Information: All chemicals were obtained from commercially
and used as received. Distilled solvents were used for column
chromatography and dried toluene was used for the reaction.
Purifications of reaction products were carried out by flash
chromatography using silica gel (200-400 mesh). Visualization of TLC
was accomplished with UV light, iodine and anisaldehyde. 1H NMR (400
MHz), and 13C NMR (120 MHz) were measured on a Brucker Avance
spectrometer. Chemical shifts are reported in parts per million (ppm, δ)
downfield from residual solvents peaks and coupling constants are
reported as Hertz (Hz). Splitting patterns are designated as singlet (s),
doublet (d), triplet (t), double dublet (dd), quintet (q),Splitting patterns that
could not be interpreted or easily visualized are designated as multiplet
(m).all other commercially available reagents and solvents were used
without further purification.
General Experimental Procedures for Preparation of 2-oxoaldhyde: 9
2-Oxoaldehyes were being prepared as per the standard procedure.
Moreover these substrates are commercially available as well.
Synthesis of tert-butyl 2-oxo-2-phenylacetate (3aa-l) and benzoic
acid derivatives (4a-f) as per direct coupling pathway: A mixture of 2-
oxoaldehyde 1 equiv (134 mg) and TBHP 2 equiv (182.26 mg) or
hydrogen peroxide 2 equiv (68.02 mg) in toluene 1.5 mL was stirred at
room temperature (25°C) for 48 hours. Completion of reaction was
monitored by TLC, Volatiles were removed under reduced pressure, and
products were obtained by column chromatography using ethyl acetate:
hexane (5-6%).
Figure 2. Plausible mechanism.
the adjacent 2-oxo group.
On the basis of our experimental results and literature
precedent,3,4,5a,e in each category, a possible reaction mechan-
ism is proposed in Figure 2. In the first set of reactions reported
for the generation of valuable 2-oxoesters, we assume that in
the direct coupling pathway, the 2-oxo group imparts H-bonding
with 2(a/b) that ultimately results in increase in -ve charge on
adjacent oxygen (the -ve charge almost approaches the t-alkoxy
oxygen charge) and thereby results in primarily homolytic
cleavage followed by alkoxy attack on adjacent CHO group. This
ultimately through proton abstraction generates the desired
product. In a similar way, organo-hydroperoxide compound
2(a/b) reacts with 2-oxoiminium to generate the desired product
in a manner as described in Figure 2. On the contrary, the
reaction of 1 with H2O2 leads to ionic peroxy attack on adjacent
CHO and results in the generation of an organoperoxy
intermediate that finally reacts in a free radical manner (as
discussed above) to produce the amino catalytic pathway, the
initial attack of H2O2 on iminium 1 as such and hydroxy radical.
The reaction of 1 with hydroxy radical lead to the formation of
acid. In the same category in ion intermediate generates the
organo hydroperoxy intermediate that ultimately undergoes
Synthesis
of
tert-butyl
2-oxo-2-phenylacetate(3aa-3al),
2-
phenylpropan-2-yl 2-oxo-2-phenylacetate (3ba-3bk) and benzoic
acid derivatives (4a-j) as per amino catalytic pathway: A mixture of
2-oxoaldehyde 1 equiv (134 mg) and pyrrolidine 0.2 equiv (14.2 mg) in
toluene 1.5 mL was stirred at room temperature. To this reaction mixture
TBHP/ hydrogen peroxide/cumene hydrogen peroxide 1.2 equiv was
added slowly. The reaction was allowed to stir at room temperature
(25°C) for 2 hours. Completion of reaction was monitored by TLC,
reaction mixture was directly charged on column. Before running
percentage onto the column, Column was neutralized with 0.5% triethyl
amine in hexane and products were obtained using ethyl acetate: hexane
(10:90).
tert-butyl 2-oxo-2-phenylacetate (3aa): Yellow oil. Yield 92% ( 189.5
mg). 1H NMR (400 MHz, CDCl3) δ 8.00 – 7.94 (m, 2H), 7.65 (t, J = 7.1 Hz,
1H), 7.51 (t, J = 7.6 Hz, 2H), 1.64 (s, 9H); 13C NMR (126 MHz, CDCl3) δ
186.90, 163.75, 134.69, 132.50, 129.93, 128.89, 84.84, 28.10.; IR
(CHCl3) ῡ[cm-1]: 2981, 2931, 2852, 1730, 1691, 1597, 1214, 1151, 985,
843, 760; HRMS (TOF) m/z [M + Na]+ Calcd for C12H14O3Na 229.0982,
found 229.0985.
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European Journal of Organic Chemistry
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tert-butyl 2-oxo-2-(p-tolyl)acetate (3ab) : Yellow oil. Yield 94% (206.4
7.64 (ddd, J = 8.5, 6.9, 1.4 Hz, 1H), 7.58 – 7.40 (m, 2H), 1.64 (s, 9H). 13
C
1
mg). H NMR (400 MHz, CDCl3) δ 7.86 (d, J = 8.2 Hz, 2H), 7.29 (d, J =
NMR (126 MHz, CDCl3) δ 189.41, 164.39, 135.65, 133.95, 133.83,
131.06, 129.15, 128.78, 128.18, 126.99, 125.71, 124.37, 84.68, 28.09. ;
IR (CHCl3) ῡ [cm-1]: 2981, 2934, 2405, 2292, 1726, 1681, 1573, 1370,
1226, 1155, 949, 843, 784.; HRMS (TOF) m/z [M + H]+ Calcd for
C16H17O3 257.1172 found 257.1195.
8.0 Hz, 2H), 2.42 (s, 3H), 1.62 (s, 9H). 13C NMR (101 MHz, CDCl3) δ
186.55, 163.95, 145.89, 130.08, 129.99, 129.59, 84.54, 28.07, 21.86.; IR
(CHCl3) ῡ[cm-1]: 2981, 2934, 2852, 1730, 1682, 1606, 1220, 1151, 984,
846, 756; HRMS (TOF) m/z [M + H]+ Calcd for C13H17O3 221.1099, found
221.1102.
tert-butyl 2-(benzo[d][1,3]dioxol-5-yl)-2-oxoacetate (3ak): Dark brown
oil. Yield 89% (222 mg).1H NMR (400 MHz, CDCl3) δ 7.56 (dd, J = 8.2,
1.7 Hz, 1H), 7.44 (d, J = 1.7 Hz, 1H), 6.89 (d, J = 8.2 Hz, 1H), 6.09 (s,
2H), 1.62 (s, 9H). 13C NMR (101 MHz, CDCl3) δ 185.11, 163.88, 153.26,
148.45, 127.53, 127.31, 108.68, 108.30, 102.18, 84.62, 28.08. ; IR
(CHCl3) ῡ [cm-1]: 2982, 2919, 2854, 1725, 1677, 1447, 1249, 1104, 997,
844, 761; HRMS (TOF) m/z [M + Na]+ Calcd for C13H14NaO5 273.0739,
found 273.0753
tert-butyl 2-(4-methoxyphenyl)-2-oxoacetate (3ac) : Yellow oil. Yield
93% (219.3 mg). H NMR (400 MHz, CDCl3) δ 7.94 (d, J = 9.0 Hz, 2H),
1
6.96 (d, J = 9.0 Hz, 2H), 3.87 (s, 3H), 1.61 (s, 9H). 13C NMR (101 MHz,
CDCl3) δ 185.49, 164.81, 164.11, 132.36, 125.54, 114.22, 84.42, 55.62,
28.08.; IR (CHCl3) ῡ[cm-1]: 2980, 2936, 2843, 1727, 1676, 1600, 1266,
1220, 1149, 986, 833, 757; HRMS (TOF) m/z [M + Na]+ Calcd for
C13H16NaO4 259.0946, found 259.0955.
tert-butyl 2-(3-methoxyphenyl)-2-oxoacetate (3ad): colourless liquid.
Yield 91% (214.5 mg).1H NMR (400 MHz, CDCl3) δ 7.54 – 7.48 (m, 2H),
7.41 (t, J = 7.9 Hz, 1H), 7.19 (dd, J = 8.2, 2.7 Hz, 1H), 3.86 (s, 3H), 1.63
(s, 9H). 13C NMR (126 MHz, CDCl3) δ 186.77, 163.78, 159.91, 133.72,
129.90, 122.96, 121.62, 113.11, 84.82, 55.48, 28.07.; IR (CHCl3) ῡ[cm-1]:
2980, 2936, 2843, 1727, 1676, 1601, 1266, 1220, 1148, 985, 832, 757;
HRMS (TOF) m/z [M + Na]+ Calcd for C13H16NaO4 259.2568, found
259.2572.
tert-butyl 2-(2-chlorophenyl)-2-oxoacetate(3al): Yellow oil 91% (218
mg). 1H NMR (400 MHz, CDCl3) δ 7.74 (dd, J = 7.7, 1.3 Hz, 1H), 7.50 (dd,
J = 11.2, 4.1 Hz, 1H), 7.45 – 7.33 (m, 2H), 1.59 (s, 9H). 13C NMR (126
MHz, CDCl3) δ 187.26, 162.29, 133.98, 133.67, 133.55, 131.64, 130.39,
127.16, 84.71, 27.75.; IR (CHCl3) ῡ [cm-1]: 2955, 2919, 2850, 2345, 1653,
1592, 1441, 1249, 1217, 1156, 1020, 876, 770.; HRMS (TOF) m/z [M +
Na]+ Calcd for C12H13ClNaO3 263.0451, found 263.0473.
2-phenylpropan-2-yl 2-oxo-2-phenylacetate (3ba). Colourless oil. Yield
89% (238.5 mg). 1H NMR (400 MHz, CDCl3) δ 8.00 – 7.94 (m, 2H), 7.67
– 7.61 (m, 1H), 7.53 – 7.46 (m, 4H), 7.41 (t, J = 7.5 Hz, 2H), 7.36 – 7.30
(m, 1H), 1.97 (s, 6H). 13C NMR (126 MHz, CDCl3) δ 186.49, 162.99,
144.42, 134.83, 132.46, 130.04, 128.93, 128.56, 127.70, 124.49, 85.38,
28.57.; IR (CHCl3) ῡ [cm-1]: 2963, 2926, 17311743, 1688, 1596, 1211,
1117, 975, 761, 698.; HRMS (TOF) m/z [M + Na]+ Calcd for C17H16NaO3
291.0992, found 291.1053.
tert-butyl 2-(4-fluorophenyl)-2-oxoacetate (3ae): Yellowish green oil.
Yield 90% ( 201.6 mg). 1H NMR (400 MHz, CDCl3) δ 8.16 – 7.91 (m, 2H),
7.19 (dd, J = 12.0, 5.4 Hz, 2H), 1.63 (s, 9H); 13C NMR (126 MHz, CDCl3)
δ 185.12, 166.60 (d, J = 257.7 Hz), 163.33, 132.74 (d, J = 9.6 Hz),
129.00 (d, J = 2.9 Hz), 116.20 (d, J = 22.6 Hz), 84.94, 27.99.; IR (CHCl3)
ῡ[cm-1]: 2980, 2923, 2853, 1728, 1688, 1599, 1212, 1148, 988, 834,
772; HRMS (TOF) m/z [M + H]+ Calcd for C12H14FO3 225.0849, found
225.0854.
2-phenylpropan-2-yl 2-oxo-2-(p-tolyl)acetate (3bb). Colourless oil.
1
tert-butyl 2-(4-chlorophenyl)-2-oxoacetate (3af): Yellow oil. Yield 91%
(218 mg). 1H NMR (400 MHz, CDCl3) δ 7.93 (d, J = 8.7 Hz, 2H), 7.49 (d,
J = 8.7 Hz, 2H), 1.63 (s, 9H). 13 C NMR (126 MHz, CDCl3) δ 185.46,
163.12, 141.33, 131.29, 130.98, 129.28, 85.09, 28.06.; IR (CHCl3) ῡ[cm-
1]: 2982, 2935, 1730, 1692, 1588, 1212, 1152, 987, 844, 734; HRMS
(TOF) m/z [M + Na]+ Calcd for C13H13ClNaO3 263.0451, found 263.0459.
Yield 92% (259.4 mg). H NMR (400 MHz, CDCl3) δ 7.82 (d, J = 8.3 Hz,
2H), 7.49 – 7.43 (m, 2H), 7.36 (t, J = 7.5 Hz, 2H), 7.31 – 7.27 (m, 1H),
7.24 (d, J = 7.9 Hz, 2H), 2.38 (s, 3H), 1.92 (s, 6H). 13C NMR (126 MHz,
CDCl3) δ 185.68, 162.70, 145.61, 144.01, 129.65, 129.52, 129.17,
128.03, 127.15, 123.99, 84.69, 28.08, 21.43.; IR (CHCl3) ῡ [cm-1]:
2969,2919, 2850,, 1650, 1605, 1454, 1247, 1175, 1018, 769, 666.;
HRMS (TOF) m/z [M + Na]+ Calcd for C18H18NaO3 305.1189, found
305.1221.
tert-butyl 2-(4-bromophenyl)-2-oxoacetate (3ag): Brown colour oil.
Yield 90% (255 mg). 1H NMR (400 MHz, CDCl3) δ 7.85 (d, J = 8.5 Hz,
2H), 7.66 (d, J = 8.5 Hz, 2H), 1.63 (s, 9H). 13C NMR (126 MHz, CDCl3) δ
185.68, 163.07, 132.28, 131.38, 131.32, 130.20, 85.12, 28.06.; IR
(CHCl3) ῡ [cm-1]: 2981, 2933, 1728, 1692, 1587, 1211, 1151, 986, 843,
751; HRMS (TOF) m/z [M + Na]+ Calcd for C12H13BrNaO3 306.9946,
found 306.9952.
2-phenylpropan-2-yl 2-(4-methoxyphenyl)-2-oxoacetate (3bc). Brown
oil. Yield 91% (271 mg). 1H NMR (400 MHz, CDCl3) δ 7.92 – 7.88 (m, 2H),
7.50 – 7.45 (m, 2H), 7.40 – 7.34 (m, 2H), 7.32 – 7.26 (m, 1H), 6.98 –
6.84 (m, 2H), 3.84 (s, 3H), 1.93 (s, 6H). 13C NMR (126 MHz, CDCl3) δ
185.08, 164.94, 163.33, 144.57, 132.52, 128.52, 128.23, 127.62, 124.48,
114.29, 85.07, 55.65, 28.58.; IR (CHCl3) ῡ [cm-1]: 2984, 2925, 2606,
1714, 1683, 1597, 1385, 1226, 1026,949, 716, 688.; HRMS (TOF) m/z
[M + Na]+ Calcd for C18H18NaO4 321.1097, found 321.1132.
tert-butyl 2-oxo-2-(4-(trifluoromethyl)phenyl)acetate (3ah): Brown
colour oil. Yield 88% (241 mg). 1H NMR (400 MHz, CDCl3) δ 8.11 (d, J =
8.1 Hz, 2H), 7.78 (d, J = 8.2 Hz, 2H), 1.64 (s, 9H). 13C NMR (126 MHz,
CDCl3) δ 185.54, 162.71, 135.64 (d, J = 32.7 Hz), 135.31, 130.28, 125.89
(d, J = 3.4 Hz), 122.28, 85.45, 28.04. ; IR (CHCl3) ῡ [cm-1]: 2989, 2924,
2853, 1731, 1694, 1584, 1323, 1168,1129, 1014, 866, 761.; HRMS
(TOF) m/z [M + Na]+ Calcd for C13H14F3O3 275.0890, found 275.0905.
2-phenylpropan-2-yl 2-(4-fluorophenyl)-2-oxoacetate (3bd): Yellowish
green oil. Yield 85% (243 mg). 1H NMR (500 MHz, CDCl3) δ 7.99 (dd, J =
8.8, 5.4 Hz, 2H), 7.49 (d, J = 7.9 Hz, 2H), 7.39 (t, J = 7.7 Hz, 2H), 7.35 –
7.29 (m, 1H), 7.15 (t, J = 8.7 Hz, 2H), 1.95 (s, 6H). 13C NMR (126 MHz,
CDCl3) δ 184.70, 166.72 (d, J = 257.9 Hz), 162.61, 144.33, 132.92 (d, J
= 9.7 Hz), 129.00 (d, J = 3.1 Hz), 128.58, 127.75, 124.48, 116.27 (d, J =
22.1 Hz), 85.51, 28.53. ; IR (CHCl3) ῡ [cm-1]: 2918, 2850, 1740, 1659,
1598, 1463, 1234, 1018, 857, 778, 699.; HRMS (TOF) m/z [M + Na]+
Calcd for C17H15FNaO3 309.0897, found 309.0928.
tert-butyl 2-(5-methylthiophen-2-yl)-2-oxoacetate (3ai): Light green oil.
Yield 89% (201 mg). 1H NMR (400 MHz, CDCl3) δ 7.85 (d, J = 3.8 Hz,
1H), 6.87 (d, J = 3.5 Hz, 1H), 2.57 (s, 3H), 1.62 (s, 9H). 13C NMR (126
MHz, CDCl3) δ 177.16, 161.50, 153.61, 137.58, 137.11, 127.51, 84.57,
27.93, 16.16.; IR (CHCl3) ῡ [cm-1]: 2980, 2924, 1728, 1650, 1446, 1230,
1153, 1060, 841, 758; HRMS (TOF) m/z [M
C11H14NaO3S 249.0561, found 249.0572.
+
Na]+ Calcd for
2-phenylpropan-2-yl 2-(4-chlorophenyl)-2-oxoacetate (3be): Brown oil.
Yield 86% (259 mg ).1H NMR (500 MHz, CDCl3) δ 7.99 – 7.84 (m, 2H),
7.49 (dd, J = 7.0, 1.3 Hz, 2H), 7.47 – 7.42 (m, 2H), 7.39 (d, J = 2.2 Hz,
2H), 7.31 (ddd, J = 7.1, 2.4, 1.3 Hz, 1H), 1.96 (d, J = 2.4 Hz, 6H). 13
NMR (126 MHz, CDCl3) δ 185.01, 162.42, 144.29, 141.42, 131.40,
130.94, 129.32, 128.58, 127.77, 124.49, 85.61, 28.53.; IR (CHCl3) ῡ [cm-
C
tert-butyl 2-(naphthalen-1-yl)-2-oxoacetate (3aj): Brown oil. Yield 93%
(238 mg).1H NMR (400 MHz, CDCl3) δ 9.06 (d, J = 8.7 Hz, 1H), 8.05 (d, J
= 8.2 Hz, 1H), 7.96 (dd, J = 7.3, 1.1 Hz, 1H), 7.86 (d, J = 8.2 Hz, 1H),
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European Journal of Organic Chemistry
10.1002/ejoc.201600795
FULL PAPER
1]: 2984, 2928, 1732, 1683, 1588, 1203, 11135, 1091, 857, 764, 699.;
HRMS (TOF) m/z [M + Na]+ Calcd for C17H15ClNaO3 325.0602, found
325.0644.
4-methylbenzoic acid (4b).10a,11 White solid. Yield 93% (126 mg). 1H
NMR (400 MHz, CDCl3) δ 8.03 (d, J = 8.1 Hz, 1H), 7.30 (d, J = 10.0 Hz,
1H), 2.46 (s, 1H).
2-phenylpropan-2-yl 2-(4-bromophenyl)-2-oxoacetate (3bf). Brown oil.
Yield 83% (288 mg). 1H NMR (400 MHz, CDCl3) δ 7.81 – 7.77 (m, 2H),
7.64 – 7.55 (m, 2H), 7.46 (dt, J = 8.3, 2.3 Hz, 2H), 7.37 (dd, J = 7.6, 6.0
Hz, 2H), 7.32 – 7.29 (m, 1H), 1.93 (s, 6H). 13C NMR (126 MHz, CDCl3) δ
185.20, 162.33, 144.22, 132.28, 131.40, 131.31, 130.34, 128.55, 127.75,
124.45, 85.61, 28.50. ; IR (CHCl3) ῡ [cm-1]: 2917, 2849, 1718, 1667,
1584, 1281, 1224, 1071, 981, 853, 796, 667.; HRMS (TOF) m/z [M +
Na]+ Calcd for C17H15BrNaO3 369.0097, found 369.0154.
4-methoxybenzoic acid (4c).10a,b,11 White solid. Yield 91% (138 mg). 1H
NMR (500 MHz, MeOD) δ 7.87 (d, J = 8.9 Hz, 1H), 6.87 (d, J = 8.9 Hz,
1H), 3.75 (s, 1H). 13C NMR (126 MHz, MeOD) δ 169.83, 165.09, 132.85,
124.01, 114.69, 55.98.
4-fluorobenzoic acid (4d).10c white solid. Yield 93% (130 mg).1H NMR
(400 MHz, CDCl3) δ 8.14 (dd, J = 8.3, 5.7 Hz, 2H), 7.15 (t, J = 8.5 Hz,
2H).
1
4-bromobenzoic acid (4e). 10a,b,c,11 Solid. Yield 90% (181 mg). H NMR
2-phenylpropan-2-yl 2-(2-chlorophenyl)-2-oxoacetate (3bg). Yellow
oil. Yield 87% (262.74 mg). 1H NMR (400 MHz, CDCl3) δ 7.69 (dd, J =
7.7, 1.7 Hz, 1H), 7.50 – 7.38 (m, 4H), 7.38 – 7.31 (m, 3H), 7.28 (dd, J =
4.9, 3.6 Hz, 1H). 1.93 (s, 6H). 13C NMR (126 MHz, CDCl3) δ 186.92,
161.64, 144.28, 134.14, 133.62, 133.47, 131.75, 130.48, 128.42, 127.65,
127.21, 124.56, 85.53, 28.06.; IR (CHCl3) ῡ [cm-1]: 2924, 2852, 1725,
1696, 1590, 1256, 1154, 1039, 854, 754, 582.; HRMS (TOF) m/z [M +
Na]+ Calcd for C17H15ClrNaO3 325.0572, found 325.0605.
(400 MHz, MeOD) δ 7.82 (d, J = 8.4 Hz, 1H), 7.55 (d, J = 8.4 Hz, 1H). 13
NMR (126 MHz, MeOD) δ 168.89, 132.84, 132.50, 131.15, 128.81.
C
3-chlorobenzoic acid (4f).11 white solid. Yield 93% (145 mg).1H NMR
(400 MHz, CDCl3) δ 8.09 (s, 1H), 8.00 (d, J = 7.7 Hz, 1H), 7.59 (d, J = 8.0
Hz, 1H), 7.42 (t, J = 7.9 Hz, 1H). 13C NMR (101 MHz, MeOD) δ 168.35,
135.52, 134.07, 133.90, 131.16, 130.57, 129.05.
2-phenylpropan-2-yl 2-(naphthalen-1-yl)-2-oxoacetate (3bh). Light
brown oil. Yield 91% (289mg). 1H NMR (400 MHz, CDCl3) δ 9.09 (d, J =
8.6 Hz, 1H), 8.04 (d, J = 8.3 Hz, 1H), 7.89 (dd, J = 7.2, 1.1 Hz, 1H), 7.85
(d, J = 8.1 Hz, 1H), 7.64 (ddd, J = 8.4, 6.9, 1.3 Hz, 1H), 7.56 – 7.43 (m,
4H), 7.38 (t, J = 7.6 Hz, 2H), 7.33 – 7.27 (m, 1H), 1.95 (s, 6H). 13C NMR
(126 MHz, CDCl3) δ 187.94, 162.52, 143.45, 134.74, 133.11, 132.97,
130.08, 128.22, 127.78, 127.52, 127.05, 126.69, 126.01, 124.73, 123.54,
123.31, 84.25, 27.52.; IR (CHCl3) ῡ [cm-1]: 2921, 2851, 1725, 1674,
1592, 1249, 1147, 1095, 890, 773, 650.; HRMS (TOF) m/z [M + Na]+
Calcd for C21H18NaO3 341.1148, found 341.1157.
2,4-dichlorobenzoic acid (4g).11 White solid. Yield 96% (90.3 mg).1H
NMR (400 MHz, CDCl3) δ 7.99 (d, J = 8.5 Hz, 1H), 7.53 (d, J = 1.9 Hz,
1H), 7.35 (dd, J = 8.5, 2.0 Hz, 1H). 13C NMR (101 MHz, CDCl3) δ 169.27,
139.56, 136.01, 133.50, 131.46, 127.18, 126.64.
4-nitrobenzoic acid (4h).10a, 11 Solid. Yield 94% (87.6 mg).1H NMR (400
MHz, MeOD) δ 8.23 (d, J = 8.8 Hz, 2H), 8.13 (d, J = 8.8 Hz, 2H).
5-methylthiophene-2-carboxylic acid (4i):12a White solid. Yield 93%
(85.7 mg).1H NMR (500 MHz, CDCl3) δ 7.71 (d, J = 2.5 Hz, 1H), 6.81 (s,
1H), 2.55 (s, 3H). 13C NMR (126 MHz, CDCl3) δ 165.61, 147.76, 133.41,
128.01, 124.63, 13.78.
2-phenylpropan-2-yl 2-(5-methylthiophen-2-yl)-2-oxoacetate (3bi).
Light Green oil. Yield 88% (253 mg).1H NMR (400 MHz, CDCl3) δ 7.80 (d,
J = 3.8 Hz, 1H), 7.49 – 7.44 (m, 2H), 7.41 – 7.34 (m, 2H), 7.32 – 7.23 (m,
1H), 6.83 (dd, J = 3.9, 1.0 Hz, 1H), 2.54 (s, 3H), 1.94 (s, 6H). 13C NMR
(126 MHz, CDCl3) δ 176.79, 161.00, 153.90, 144.44, 137.87, 137.14,
128.52, 127.69, 127.57, 124.43, 85.20, 28.49, 16.16. .; IR (CHCl3) ῡ [cm-
1]: 2962, 2924, 2857, 1731, 1651, 1447, 1232, 1167, 1060, 8902, 700,
652.; HRMS (TOF) m/z [M + Na]+ Calcd for C16H16NaO3S 311.0712,
found 311.0756
benzofuran-3-carboxylic acid (4j).12b,c White solid.Yield 90% (84 mg).1H
NMR (500 MHz, MeOD) δ 7.72 (d, J = 7.9 Hz, 1H), 7.57 (t, J = 4.2 Hz,
2H), 7.51 – 7.43 (m, 1H), 7.31 (t, J = 7.5 Hz, 1H). 13C NMR (126 MHz,
MeOD) δ 161.09, 155.74, 146.02, 127.33, 127.10, 123.50, 122.64,
113.45, 111.56.
Procedure for control experiments:
2-phenylpropan-2-yl 2-oxo-2-(thiophen-3-yl)acetate (3bj). Light yellow.
Yield 88% (241 mg). 1H NMR (400 MHz, CDCl3) δ 8.33 (dd, J = 2.9, 1.1
Hz, 1H), 7.62 (dd, J = 5.1, 1.1 Hz, 1H), 7.45 (dd, J = 8.3, 0.9 Hz, 2H),
7.39 – 7.33 (m, 2H), 7.32 – 7.29 (m, 1H), 1.92 (s, 6H). 13C NMR (126
MHz, CDCl3) δ 178.89, 161.68, 144.45, 137.62, 137.42, 128.56, 127.74,
127.62, 126.73, 124.42, 85.11, 28.51.; IR (CHCl3) ῡ [cm-1]: 2961, 2920,
1738, 1667, 1509, 1235, 1164, 1079, 997, 787, 700.; HRMS (TOF) m/z
[M + Na]+ Calcd for C15H14NaO3 297.0556, found 297.0597
Experiment 1. A reaction vessel charged with a stir bar and toluene 1.0
mL, was added with 2-oxoaldehyde 1.0 equiv (0.746 mmol) and
pyrrolidine 0.2 equiv (0.149 mmol). To this reaction mixture TEMPO 8
equiv. ( 5.95 mmol) and TBHP 1.2 equiv (0.8955 mmol) was added .The
reaction was allowed to stir at room temperature for 2-6 hours. Reaction
was continuously monitored by TLC and no product formation was
observed.
2-phenylpropan-2-yl 2-oxo-2-(4-(trifluoromethyl)phenyl)acetate 3ak):
Brown oil. Yield 84% (282 mg ). 1H NMR (500 MHz, CDCl3) δ 8.21 (s,
1H), 8.13 (d, J = 7.8 Hz, 1H), 7.88 (d, J = 7.8 Hz, 1H), 7.62 (t, J = 7.8 Hz,
1H), 7.53 – 7.44 (m, 2H), 7.40 (t, J = 7.6 Hz, 2H), 7.34 – 7.31 (m, 1H),
1.96 (d, J = 3.2 Hz, 6H). 13C NMR (126 MHz, CDCl3) δ 13C NMR (126
MHz, CDCl3) δ 184.81, 162.07, 144.07, 133.18, 133.08, 131.01 (d, J =
3.5 Hz), 129.63, 128.61, 127.84, 126.86 (d, J = 4.0 Hz), 124.46, 85.95,
28.44.; IR (CHCl3) ῡ [cm-1]: 2955, 2917, 2850, 1697, 1651, 1332, 1170,
1129, 1073, 923, 794, 692.; HRMS (TOF) m/z [M + Na]+ Calcd for
C18H15F3NaO3 359.0866, found 359.0901
Experiment 2. A mixture of 2-oxoaldehyde 1.0 equiv (0.746 mmol) and
pyrrolidine 0.2 equiv (0.149 mmol) was stirred at room temperature. To
this reaction mixture TEMPO 2 equiv. (1.49 mmol) and Hydrogen
peroxide 1.2 equiv (0.8955 mml ) was added. Reaction was kept for 12
hours and was continuously monitored by TLC, only traces of product
were observed.
Experiment 3. A reaction vessel charged with a stir bar and toluene 1.0
mL, was added with 2-oxoaldehyde 1.0 equiv (0.746 mmol) and
pyrrolidine 0.2 equiv (0.149 mmol). To this reaction mixture TEMPO 8
equiv. (5.95 mmol) and Cumene 1.2 equiv (0.8955 mmol) was
added .The reaction was allowed to stir at room temperature for 2-6
hours. Reaction was continuously monitored by TLC and no product
formation was observed.
Benzoic acid (4a).10,11 White solid. Yield 95% (116 mg). Melting point
(120-124 OC ) .1H NMR (400 MHz, MeOD) δ 8.03 (d, J = 7.6 Hz, 1H),
7.54 (t, J = 7.3 Hz, 1H), 7.43 (t, J = 7.6 Hz, 1H). 13C NMR (101 MHz,
MeOD) δ 170.06, 134.11, 131.86, 130.80, 129.51.
This article is protected by copyright. All rights reserved

European Journal of Organic Chemistry
10.1002/ejoc.201600795
FULL PAPER
Experiment 4. A reaction vessel charged with a stir bar and toluene 1.0
mL, was added with benzaldehyde 1.0 equiv (0.939 mmol) and
pyrrolidine 0.2 equiv (0.187 mmol). To this reaction mixture oxidant
(H2O2/TBHP/Cumene) 2.0 equiv (1.879 mmol) was added .The reaction
was allowed to stir at room temperature for 6-12 hours. Reaction was
continuously monitored by TLC and no product formation was observed.
cMullin, N. G. Sapiezynski, E. S. Jang, M. J. B Aguila, T. R. Cundari,T.
H. Warren, J. Am. Chem. Soc. 2012, 134, 17350−17353.
[2] (a) R. D. Bach, A. Y. Philippe, H. B. Schlegel, J. Am. Chem. Soc. 1996,
118, 12758–12765. (b) M. Berasategui, Paci. M. A. Burgos, G. A.
Argüello. J. Phy. Chem. A 2014, 118, (12), 2167-2175. (c) R. D. Bach,
J. Phys. Chem. 2011, 115, (40), 11087-11100.(d) J. Frank, E.
Rabinowitch, Trans. Furaday Soc. 2011, 30(120),1934-1935. (e) E. V.
Rokhina, K. Makarova. E. A. Golovina, H. Van As, J. Virkutyte, Environ.
Sci.Technol. 2010, 44, (17), 6815-6821.
Experiment 5. A reaction vessel charged with a stir bar and toluene 1.0
mL, was added with 2-oxo-2-phenylacetic acid 1.0 equiv (0.666 mmol)
and pyrrolidine 0.2 equiv (0.133 mmol). To this reaction mixture oxidant
(H2O2/TBHP/Cumene) 2.0 equiv (1.333 mml) was added .The reaction
was allowed to stir at room temperature for 6-12 hours. Reaction was
continuously monitored by TLC and no product formation was observed.
[3] (a) D. H. R. Barton, V. N. Le Gloahec, H. Patin, F. Launay, New J. Chem.
1998, 22, 559-563. (b) M. Uyanik, H. Okamoto, T. Yasui, K. Ishihara,
Science, 2010, 328, 1376-1379. (c) Y. Zhu, H. Yan, L. Lu, D. Liu, G.
Rong, J. Mao, J. Org. Chem. 2013, 78, 9898-9905. (d) A.Lopalco, G.
Dalwadi, S. Niu, R. L. Schowen, J. Douglas, V. J. Stella, J. Phram. Sci.
2015, DOI 10.1002/jps.24653. (e) S-J. Jin, K. A. Pramod, S. M.
Lawrence, J. Org. Chem. 1990, 55, 3011-3018 (f) X. Sun, M. Wang, P.
Li, X. Zhang, L. Wang, Green Chem. 2013, 15, 3289-3294.(g) V.
Venkateswarlu, K. A. A. Kumar, S. Gupta, D. Singh, R. A. Vishwakarma,
S. D. Sawant, Org. Biomol. Chem. 2015, 13, 7973-7978.
Experiment 6. A reaction vessel charged with a stir bar and Ethanol 1.0
mL, was added with 2-oxoaldehyde 1.0 equiv (0.746 mmol) and
pyrrolidine 0.2 equiv (0.149 mmol). To this reaction mixture TBHP 1.2
equiv (0.8955 mmol) was added .The reaction was allowed to stir at room
temperature for 2-6 hours. Reaction was continuously monitored by TLC
and no product formation was observed.
[4]
(a) W. Wei, C. Zhang, Y. Xu, X.Wan, Chem. Commun. 2011, 47, (38),
10827-10829 (b) M. S. Kharasch, A. Fono, J. Org. Chem. 1959, 24,
606-609. (c) M. Ganesh, G. Srimanta, G. Anupal, K. R. Saroj, P. K
Bhisma, Chem. Commun, 2013, 49, 3031-3033.
Experiment 7. A reaction vessel charged with a stir bar and toluene 1.0
mL, was added with pyrrolidine-1-carbaldehyde 1.0 equiv (1.0 mmol) and
pyrrolidine 0.2 equiv (0.2 mmol). To this reaction mixture oxidant
(H2O2/TBHP/Cumene) 1.2 equiv (1.2 mmol) was added .The reaction
was allowed to stir at room temperature for 6-12 hours. Reaction was
continuously monitored by TLC and no product formation was observed.
[5]
(a) R. Deshidi, M. A. Rizvi, B. A. Shah, RSC Adv. 2015, 5(110), 90521-
90524. (b) Z. Liu, J. Zhang, S. Chen, E. Shi, Y. Xu, X. Wan, Angew.
Chem. Int. Ed. 2012, 51(13), 3231-3235. (c) K. Rout, S. Guin, K. K.
Ghara, A. Banerjee, B. K. Pate, Org.Lett. 2012, 14, 3982.(d) X. –F. Wu,
J. –L. Gong, X. Qi, Org. Biomol. Chem. 2014, 12, 5807−5817. (e) T. K.
Achar, P. Mal. J. Org. Chem. 2015, 80(1), 666-672.
Experiment 8. A reaction vessel charged with a stir bar and toluene 1.0
mL, was added with 2-acetylbenzaldehyde 1.0 equiv (1.0 mmol) and
pyrrolidine 0.2 equiv (0.2 mmol). To this reaction mixture oxidant
(H2O2/TBHP/Cumene) 1.2 equiv (1.2 mmol) was added .The reaction
was allowed to stir at room temperature for 6-12 hours. Reaction was
continuously monitored by TLC and no product formation was observed.
[6]
[7]
(a) S. Xie, Y. Zhang, O. Ramstrom, M. Yan, Chem. Sci. 2016, 7(1),
713-718. (b) Y. –F. Guo,T.-L. Ren, B.-H. Xu, Y. –F. Wang, S.-J. Zhang.
Asian. J. Org. Chem. 2016, 5(4), 568-574. (c) Y–F. Guo, B.-H. Xu, T. Li,
L. Wang, S.-J. Zhang. Org. Chem. Fron. 2016, 3(1), 47-52. (d) A. Bose,
P. Mal, J. Org. Chem. 2015, 80(21), 11219-11225.
(a) N. Battini Khushwaha, A. P. Gupta, P. P. Singh, Q. N. Ahmed, J. Org.
Chem. 2015, 80, 11588−11592. (d) N. Battini, S. Battula, R. R.Kumar,
Q. N. Ahmed, Org. Lett. 2015, 17, 2992-2995. (e) A. K. Padala, N.
Mupparapu, D. Singh, R. A. Vishwakarma, Q. N. Ahmed, Eur. J. Org.
Chem. 2015, 3577-3586. (f) N. Mupparapu, R. A. Vishwakarma, Q. N.
Ahmed, Tetrahedron, 2015, 71, 3417-3421. (g) N.Mupparapu, N.
Battini , S. Battula , S. Khan , R. A. Vishwakarma, Q. N. Ahmedꢀ, Chem.
Eur. J. 2015, 21, 2954-2960. (h) N. Battini, A. K. Padala, N. Mupparapu,
R. A. Vishwakarma, Q. N. Ahmed, RSC Adv. 2014, 4, 26258-26263. (i)
S. Khan, S. Battula, Q. N. Ahmed, Tetrahedron. 2016, 72, 4273-4279.
Acknowledgements
S. Khan thank to DST for awarding senior research fellowship
and AcSIR for Ph.D. registration. The authors thank the
analytical department of IIIM as well. Finally, this work was
generously supported by CSIR network project through Grant
No. BSC0108. IIIM/1956/2016.
[8] (a) H. Baxendale and J.A Willson, trans. Faraday. soc. 1957, 53, 344.(b)
B. Jack, A. L. Mansell, R. J. M. Ratclif, Chem. Comm. 1968, 48-49. (c)
M. Anbar P. Neta, Isitemat. J. Appl. Rad. Isot. 1965, 16, 227-242. (d) K .
Livingston, H. Zeldes, J. Chem. Phys. 1966, 44(3), 1245-1258.
Keywords: 2-oxo driven • organo-hydroperoxides • iminium ion •
ionic • radical •
[9]
N, Mupparapu. S. Khan, S. Battula, M. Kushwaha, A. P. Gupta, Q. N.
Ahmed, R. A. Vishwakarma, Org. Lett. 2014, 16, 1152-1155.
[10] (a) T. M. Shaikh, F. E. Honga, Adv. Synth. Catal. 2011, 353, 1491 –
1496. (b) S. Battula, A. Kumar, Q. N. Ahmed, Org. Biomol. Chem. 2015,
13, 9953–9956. (c) K. Nemoto, H. Yoshida, N. Egusa, N. Morohashi, T.
Hattori, J. Org. Chem. 2010, 75, 7855–7862.
[1]
(a) W. Zhang, A. Basak, Y. Kosugi, Y. Hoshino, H. Yamamoto, Angew.
Chem. Int. Ed. 2005, 44, 4389-4391. (b) W. Zhang, H. Yamamoto. J.
Am. Chem. Soc. 2007, 129, 286-287. (c) X, Lu. Y. Liu, B. Sun, B.
Cindric, L. Deng. J. Am. Chem. Soc., 2008, 130, 8134-8135. (d) T.-H.
Zhu, S. Y. Wang, Y.Q. S. Tao, S. J. Ji, Org. Lett. 2015, 17, 1974-1977.
(e) H. Aruri, U. Singh, S. Sharma, S. Gudup, M. Bhogal, S. Kumar, D.
Singh, V. K. Gupta, R. Kant, R. A. Vishwakarma, P. P. Singh, J. Org.
Chem. 2015, 80(3), 1929-1936. (f) S. Hovorka, C. Schoneich, J. Pharm.
Sci. 2001, 90(3), 253–269. (g) Y. Wu, J. Levons, A. S. Narang, K.
Raghavan, V. M. Rao, AAPS. Pharm. Sci. Tech. 2011, 12(4), 1248–
1263. (h) A. Tillack, I. Rudloff, M. Beller, Eur. J. Org. Chem. 2001, 3,
523-528.(i) P. Malik, D. Chakraborty, Synthesis. 2010, 21, 3736-3740.
(j) J. Mo, L. Wang, X. Cui. Org. lett. 2015, 17(20), 4960-4963. (k) H.
Zhu, P. Chen , G. Liu, J. Am. Chem. Soc. 2014, 136, 1766-1769. (l) H.
Egami, T. Katsuki, J. Am. Chem. Soc. 2007, 129, 8940-8941.(m) D.
Uraguchi, R. Tsutsumi and T. Ooi, J. Am. Chem. Soc. 2013, 135,
8161-8164. (n) F. Minisci, Fontana, S. Araneo, F. Recupero, J. Chem.
Soc., Chem. Commun. 1994, 16, 1823-1824. (o) R. T. Gephart, C. L.
[11] T. M. Shaikh, S. Arumugam, Eur. J. Org. Chem. 2008, 29, 4877–4880.
[12] (a) B. Pieber, T. Glasnov, C. O. Kappe, RSC Adv, 2014, 4, 13430-
13433. (b) K. A. A. Kumar, V. Venkateswarlu, R. A. Vishwakarma, S. D.
Sawant, Synthesis. 2015, 13, 7973-7978. (c) T. H. Nguyen, N. T. T.
Chau, A. S. Castanet, K. P. P. Nguyen, J. Mortier, J. Org. Chem., 2007,
72, 3419-3429.
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European Journal of Organic Chemistry
10.1002/ejoc.201600795
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Key Topic*
Shahnawaz khan,Qazi Naveed Ahmed*
Page No. – Page No.
2-Oxo Driven Coupling Reaction of 2-
oxoaldehydes/2-oxoiminium ions and
hydroperoxides at Room
for Table of Contents
Temperature
An efficient 2-oxo group promoted direct coupling method between 2-oxoaldehydes and hydroperoxides has been developed and
applied successfully for the generation of different 2-oxoesters and acids.
*2-Oxo driven
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