Synthesis of γ-keto sulfones by copper-catalyzed oxidative sulfonylation of tertiary cyclopropanols

Article abstract of DOI:10.1039/c7ob01605k

Tertiary cyclopropanols undergo ring-opening oxidative sulfonylation to afford γ-keto sulfones when reacting with sulfinate salts in the presence of a copper(ii) acetate catalyst and an oxidant (tert-butyl hydroperoxide or atmospheric oxygen). Various fluoroalkyl, aryl and alkyl sulfinate salts are successfully employed as sulfonylation reagents, affording the corresponding sulfones in up to 94% yields. The experimental protocol is mild and tolerates a number of functionalities in the cyclopropanol substrate. The reaction proceeds via a one-pot oxidation-Michael addition mechanism and can serve as a useful addition to the existing methods for the preparation of γ-keto sulfones based on the sulfa-Michael reaction.

Full text of DOI:10.1039/c7ob01605k

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Synthesis of γ-keto sulfones by copper-catalyzed oxidative
sulfonylation of tertiary cyclopropanols
Yulia A. Konik,a Gábor Zoltán Elek,b Sandra Kaabel,b Ivar Järving,b Margus Loppb and Dzmitry G.
Received 00th January 20xx,
Accepted 00th January 20xx
Kananovichb*
DOI: 10.1039/x0xx00000x
Tertiary cyclopropanols undergo ring-opening oxidative sulfonylation to afford γ-keto sulfones when reacting with sulfinate
salts in the presence of copper(II) acetate catalyst and an oxidant (tert-butyl hydroperoxide or atmospheric oxygen). Various
fluroalkyl, aryl and alkyl sulfinate salts are successfully employed as sulfonylation reagents, affording the corresponding
sulfones up to 94% yields. The experimental protocol is mild and tolerates number of functionalities in the cyclopropanol
substrate. The reaction proceeds via one-pot oxidation – Michael addition mechanism and can serve as a useful addition to
the existing methods for preparation of γ-keto sulfones based on Sulfa-Michael reaction.
www.rsc.org/
Introduction
Synthesis of sulfones attracts considerable attention because
numerous valuable compounds, such as pharmaceuticals and
agrochemicals, contain sulfonyl group as a key structural motif.1
In addition, sulfones are well-known intermediates for
construction of C-C bonds,2 for example in Julia olefination2b
and Ramberg-Bäcklund2c reactions.
γ-Keto sulfones are traditionally prepared from α,β-enones via
Michael addition of sulfinate anion,3 or thiols4 and subsequent
oxidation5 of intermediate thio-substituted ketones. Alternative
approaches have been reported in recent years, such as N-
heterocyclic carbene-catalyzed intermolecular Stetter reaction
of aldehydes with α,β-unsaturated sulfones,6 along with
palladium7 and silver-catalyzed8 transformation of allylic
alcohols via in situ formation of α,β-enone intermediate.7
As a contribution to further development in the field, we report
Scheme 1 Synthesis of γ-keto sulfones 2–10 (eq. 1) and distally fluorinated ketones
11 (eq. 2) from cyclopropanols 1 and sulfinate salts
transformations, cyclopropanols act as synthetic equivalents of
homoenolate anions, thus providing a “polarity inverted”
alternative to Michael addition reactions. This alternative route
to β-functionalized ketones is especially beneficial when the
corresponding addition reaction to the enone double bond fails
to afford the desired product.11,10a Easy access to diversely
functionalized cyclopropanols by Kulinkovich cyclopropanation
of carboxylic esters12 further increases attractivity of these
strained compounds as precursors of β-functionalized ketones.
in the current paper synthesis of γ-keto sulfones
2
–10 via
oxidative sulfonylation of tertiary cyclopropanols (
1
) with
sulfinate salts (Scheme 1, eq. 1) in the presence of copper(II)
acetate.
Cyclopropanols
1 are synthetically useful compounds due to
facile cleavage of the strained cyclopropane ring under mild
conditions. Regioselective ring opening of cyclopropanols at
adjacent to the alcohol group carbon-carbon bonds is assisted
by transition metals via single- or two-electron redox processes9
and results in β-functionalized carbonyl compounds.10 In these
Results and discussion
We reported recently that tertiary cyclopropanols
1 when
a.Department of Organic Chemistry, Belarusian State University, Leningradskaya
14, 220050, Minsk, Belarus.
reacting with fluorinated sulfinate salts in the presence of
copper(II) acetate catalyst (20–100 mol%) and tert-butyl
hydroperoxide (TBHP, 3 equiv.) result in distally fluorinated
ketones 11 (Scheme 1, eq. 2).13,11 In this transformation,
b.Department of Chemistry and Biotechnology, Tallinn University of Technology,
Akadeemia tee 15, 12618 Tallinn, Estonia. E-mail: dzmitry.kananovich@ttu.ee.
† Footnotes relating to the title and/or authors should appear here.
Electronic Supplementary Information (ESI) available: Experimental details and
spectral data. See DOI: 10.1039/x0xx00000x
This journal is © The Royal Society of Chemistry 20xx
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fluorinated sulfinate salts serve as a precursor of reactive was formed (Table 1, entries 6 and 7). It was alsVoiewpoArstiscilebOlenlitnoe
DOI: 10.1039/C7OB01605K
fluoroalkyl copper species, presumably via intermediate reduce amount of PhSO2Na and TBHP oxidant: high yield of
formation of fluoroalkyl radicals. Good yields of the sulfone 3b was achieved with only 1.5 equiv. of both PhSO2Na
corresponding fluorinated ketones 11 were attained with and TBHP (Table 1, entries 4-5). Moreover, the reaction with
sodium
α,α-difluoroalkylsulfinates. On the other hand, the use of favorable industrial oxidizer. Although the reaction was slower
sodium fluoromethylsulfinate (CFH2SO2Na) and compared to TBHP (Table 1, entry 8), stirring of the reaction
triflinate
(Langlois
reagent)
and PhSO2Na also proceeds well with atmospheric oxygen, the most
difluoromethylsulfinate (CHF2SO2Na) was not so successful, mixture in an open flask afforded acceptable yield of sulfone 3b
affording the corresponding fluorinated ketones in low yields, even with 20 mol% of Cu(OAc)2 catalyst (Table 1, entry 9). To
likely due to lower stability of the corresponding fluoromethyl confirm the role of atmospheric oxygen as oxidant, an
and difluoromethyl radicals.14 Instead, reaction of CHF2SO2Na (3 experiment with no air access (in a Schlenk tube under argon
atmosphere) was performed (entry 10). We observed that the
reaction mixture turned yellow after 3 h (due to reduction of
Cu(II) into Cu(I) species) and the reaction stopped. NMR analysis
revealed incomplete transformation of cyclopropanol 1b: only
65% of the substrate was consumed and transformed into
sulfone 3b due to oxidation with Cu(II) species. After exposing
the content of the reaction vessel to air, oxidation of Cu(I) into
Cu(II) species took place, along with the full conversion of
equiv.) with benzyl cyclopropanol 1a (R1 = PhCH2) in methanol,
starting material 1b into sulfone 3b
.
together with Cu(OAc)2 (1 equiv.) and TBHP (3 equiv.),
formation of difluoromethyl sulfone 2a as major product in
nearly 57% yield (by 1H NMR) was observed (Scheme 2).
Table
1 Optimization experiments for copper-catalyzed oxidative sulfonylation of
cyclopropanol 1b.
Pure crystalline fluorinated sulfone 2a was isolated from the
reaction mixture by precipitation with hexane from the solution
in chloroform or diethyl ether. The structure of sulfone 2a was
confirmed by NMR, exhibiting signal of CHF2 moiety at δ = 6.16
ppm (t, JHF = 52.9 Hz) in 1H NMR and at δ = −122.9 ppm (d, JHF
=
52.9 Hz) in 19F NMR spectra. IR spectrum of 2a revealed two
characteristics for sulfones strong bands at 1345 and 1160 cm-1.
Similarly, amyl cyclopropanol 1b afforded the corresponding
difluoromethyl sulfone 2b in nearly 55% yield (by 1H NMR)
under the same reaction conditions, along with methoxy ketone
13b (10%) and difluoro ketone 11b (35%) by-products (Table 1,
entry 1). Although the formation of 11b can be suppressed by
introducing 20 mol% of Fe(OAc)2 as an additive in addition to
copper(II) acetate (entry 2), it resulted in only slight increase in
yield of the target sulfone 2b (up to 60%) due to formation of
vinyl ketone 12b as an additional by-product in about 20% yield.
Nevertheless, the latter can be further converted into the target
sulfone product 2b using prolonged reaction time (72 h) via the
Sulfa-Michael reaction, thus allowing to achieve acceptable 77%
yield of 2b (entry 3).
Entry
Cu cat.
mol%
R2
(x eq.)
Oxidant
Time
Yield of
sulfone
(%)a
55
60
77
94
92
63
0
1
2
3
4
5
6
7
8
9
100
100b
100b
100
50
20
0
100
20
100
CF2H (3 eq.)
CF2H (3 eq.)
CF2H (3 eq.)
Ph (1.5 eq.)
Ph (1.5 eq.)
Ph (1.5 eq.)
Ph (1.5 eq.)
Ph (1.5 eq.)
Ph (1.5 eq.)
Ph (1.5 eq.)
TBHP
TBHP
TBHP
TBHP
TBHP
TBHP
TBHP
O2
24 h
24 h
72 h
0.5 h
1 h
1 h
1 h
2 h
3 h
In order to expand the scope of the method, the sulfonylation
reaction of amyl cyclopropanol
(
1b)
with sodium
benzenesulfinate (PhSO2Na) was further explored (Table 1,
entries 6-12). To our delight, in contrast to slowly reacting
fluorinated methanesulfinate salt, the reaction with PhSO2Na
was fast and completed within 30 min (entry 4) affording phenyl
sulfone 3b in high 94% yield. The remarkable difference of this
reaction was a possibility to reduce the amount of the Cu
catalyst and to avoid use of iron salt additive. Thus, in the
presence of only 1 equiv. of Cu(OAc)2, without additional Fe co-
catalyst, the yield of sulfone product 3b remained high until 50
mol% of Cu catalyst loadings (Table 1, entries 4 and 5). However,
further reduction of the catalyst amount led to diminished
yields, and in the absence of copper catalyst, no sulfone product
97
81
60d
O2
c
10
-
3 h
Yields were determined by 1H NMR spectroscopy. 20 mol% Fe(OAc)2 as an
additive. c The reaction was carried out under argon in a Schlenk tube. 35% of
starting material (1b) remained.
a
b
d
With the established reaction conditions, a number of
cyclopropanols 1a
arylsulfinate salts were used for preparation of γ-keto sulfones
10 (Scheme 3). Difluoro- and fluoromethyl sulfones and 4
-h, along with fluoromethyl-, alkyl- and
2
-
2
were prepared from the corresponding sulfinate salts (3 equiv.)
2 | J. Name., 2012, 00, 1-3
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DOI: 10.1039/C7OB01605K
a
Conditions A: cyclopropanol 1 (0.5 mmol), sulfinate salt (3 equiv.), Cu(OAc)2·H2O (1 equiv.), Fe(OAc)2 (20 mol%), TBHP (3 equiv., 70% in water, dropwise addition 20
min), r.t., 72 h; Conditions B: cyclopropanol 1 (1 mmol), sulfinate salt (1.5 equiv.), Cu(OAc)2·H2O (1 equiv.), TBHP (1.5 equiv., 70% in water, dropwise addition 20 min),
open flask, r.t., 1 h; Conditions C: cyclopropanol 1 (1 mmol), sulfinate salt (1.5 equiv.), Cu(OAc)2·H2O (1 equiv.), open flask, stirring at r.t., 2-5 h. b Yield of solid product,
isolated by filtration after evaporation of solvent used for extraction and hexane washing or obtained by precipitation from chloroform with hexane (see ESI). c Yield of
isolated product after column chromatography on silica gel. d Starting from 1 g of cyclopropanol 1b, sulfone 9b was obtained in 76% yield after recrystallization from
hexane (see ESI). e Not isolated. Yield determined by 1H NMR spectroscopy.
and TBHP as oxidant (3 equiv.) in the presence of Cu(OAc)2 (1 functionalized cyclopropanols 1c and 1d smoothly reacted with
equiv.) and iron acetate additive (20 mol%; conditions A). sulfinate salt CHF2SO2Na to afford the corresponding sulfones
Besides the above mentioned alkyl cyclopropanols 1a and 1b
,
2c and 2d (Scheme 3). After 72 h reaction time, the latter were
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isolated in 41% and 43% yields respectively as crystalline solids yields of the corresponding sulfone products. Thus, with the
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by simple precipitation with hexane from chloroform solution model substrate 1b, sulfone 3b was isolatDeOdI:in108.1403a9n/dC79O0B%01y6i0e5ldK
of the crude reaction mixtures. Phenyl cyclopropanol 1e was correspondingly (Table 3). Similar yields (47% and 55%) of
more reactive than aliphatic substrates, affording the phenyl sulfone 3a were also attained in the case of benzyl
corresponding difluoromethyl sulfone 2e in noticeably higher cyclopropanol 1a. The use of atmospheric oxygen was
yield. The same transformation performed with cyclopropanols noticeably beneficial only for preparation of compound 3f (76%
1a
(CFH2SO2Na) yielded the corresponding monofluoromethyl Further examples of functionalized aliphatic and aromatic
sulfones In this case, only the reaction of benzyl sulfones 10 have been prepared and isolated in 47–94%
, 1b and 1d and sodium monofluoromethylsulfinate vs 47% yield with TBHP).
4
.
3, 5-
cyclopropanol 1a with CFH2SO2Na was inefficient, yielding the yields following the same experimental protocol (Table 3). A
corresponding sulfone 4a in low 28% yield (37% yield by NMR number of substituted benzenesulfinates (p-Me, F, Cl, CF3) in
of the crude reaction mixture).15 X-ray analysis of the crystals of reaction with cyclopropanol 1b afforded the corresponding aryl
compound 4a provided final proof of the sulfone structure sulfone products
(Scheme 3).‡
PhSO2Na. Alkylsulfinate salts (sodium methylsulfinate and
The preparative transformations with PhSO2Na and several sodium 1-methyl 3-sulfinopropanoate) smoothly afforded solid
cyclopropanol substrates (1a 1b 1f) were performed in a 1 alkyl sulfones and 10, which were isolated in 47–71% yields by
5-8 in nearly the same yields as parent
,
,
9
mmol scale using TBHP (conditions B) and atmospheric oxygen simple filtration after evaporation of the solvent used for
(conditions C) as an oxidizer, in the presence of 1 equiv. of extraction (see ESI). In a gram-scale experiment, 76% yield of
Cu(OAc)2. As a rule, both procedures B and C afforded similar pure sulfone 9b was attained after recrystallization from
Scheme 4 Plausible mechanisms of the sulfonylation reaction and control experiments.
4 | J. Name., 2012, 00, 1-3
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hexane. It is worth noting that in the case of unsaturated preparation of γ-keto sulfones. The reaction proceeds under
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DOI: 10.1039/C7OB01605K
compounds 3g and 3h, terminal and conjugated double bonds mild conditions and demonstrates good functional group
in the products remained intact, and no sulfonylation of olefin tolerance. The possibility to use atmospheric oxygen as an
moieties occurred.16
oxidant adds green dimension to the method. Taking into
Discussing possible mechanisms of the sulfonylation reaction, account the importance of sulfone group as a pharmacophore
three possibilities could be considered (Scheme 4). All the fragment and bioisoster of the carbonyl group22 the developed
mechanistical pathways begin with the ring cleavage of approach is a useful addition to the existing methods for
cyclopropane with electrophilic Cu(II) species producing preparation of γ-keto sulfones based on Sulfa-Michael
β-copper(II) ketone A 17
However, the further fate of these reactions. The reaction proceeds via one-pot oxidation –
.
reactive species could be different. The first mechanism implies Michael addition mechanism, which can be expanded for
generation of sulfonyl radical by the oxidation of sulfinate salt.16 preparation of other classes of β-functionalized carbonyl
Copper(III) intermediate
sulfonyl radical with β-copper(II) ketone
elimination of Cu(I) affords sulfone products
B
is produced by the reaction of compounds under mild reaction conditions via in situ
, and reductive generation of enone intermediates23 from cyclopropanols as
10 16e
Since easily available starting materials.
A
2
-
.
sulfonyl radicals are prone to attack unsaturated bonds16 and
alkenes are used to capture these species,16e smooth
production of unsaturated sulfones 3g and 3h (Scheme 3)
indicates that involvement of free sulfonyl radicals is
improbable.
Conflicts of interest
There are no conflicts to declare
The second possibility (mechanism II) implies homolysis17,18 of
CuII-carbon bond in intermediate
A
to produce oxoalkyl radical
Acknowledgements
C, which could intercept sulfonyl radical from the copper(II)
Funding from the European Union’s Seventh Framework
Program for research, technological development and
demonstration Grant No. 621364 (TUTIC-Green), from the
Centre of Excellence in Molecular Cell Engineering Grant No.
2014-2020.4.01.15-0013, from the Estonian Ministry of
Education and Research Grant IUT19-32 and from Tallinn
University of Technology Grant No B58 is gratefully
acknowledged. Y.K. is grateful to the Dora Plus program for
financial support of a short research stay at the Tallinn
University of Technology. S.K. and I.J. are grateful to research
Grants IUT19-9 and PUT692 for support. We are thankful to the
reviewers for helpful discussion regarding the reaction
mechanism.
sulfinate, generated in situ. Finally, the third mechanism
suggests intermediate formation of α,β-enone 12 from
organocopper compound
via homolysis and oxidation of oxoalkyl radical C 19
subsequent Sulfa-Michael reaction affords sulfones 10
A
via elimination of copper(0)17b or
.
The
2
-
.
To distinguish between these two alternative mechanisms, a
number of control experiments have been performed (Scheme
4). First of all, we found that cyclopropanol 1b was smoothly
oxidized to enone 12b when reacted with both TBHP or
atmospheric oxygen in the presence of Cu(OAc)2 (eq. 1).20
Furthermore, enone 12b quickly reacts with PhSO2Na under
standard reaction conditions, to afford sulfone 3b (eq. 2). The
same addition reaction with less nucleophilic CHF2SO2Na was
significantly slower and 93% conversion of the starting material
was achieved after 48 h reaction time (eq. 3). Since enone 12b
was indeed detected as intermediate in the sulfonylation
reaction of 1b with CHF2SO2Na (see above), these results
strongly support operation of the one-pot oxidation – Michael
addition mechanism.
Experimental
Experimental details and spectral data for new compounds are
given in the Electronic Supporting Information (ESI).
Experiments performed with disubstituted cyclopropanol 14
provide further evidences for the formation of enone
intermediates (Scheme 4, eq. 4 and 5). Cyclopropanol 14 affords
α-methylene ketone 15 when oxidized with TBHP in the
presence of Cu(OAc)2.21 On the other hand, we found that
ketone 15 is inert towards the subsequent addition of PhSO2Na
(eq. 4). In accordance with these observations, we found that
when cyclopropanol 14 was submitted to the standard reaction
conditions (eq. 5), unsaturated ketone 15 was formed as major
product (~70% yield by NMR), with only trace amounts of
sulfone products detected.
Notes and references
‡ Crystal data for 3a: C11H13FO3S, Mr =244.27 g/mol, monoclinic,
P21/c (no. 14), a = 15.2903(14) Å, b = 5.0921(4) Å, c =
16.0912(14) Å, β = 115.067(11)°, V = 1134.85(19) Å3, Z = 4, Cu-Kα
radiation (λ = 1.54184 Å) at T = 123.0 K, μ(CuKα) = 2.600 mm-1,
Dcalc = 1.430 g/cm3, 9604 reflections measured (6.382° ≤ 2Θ ≤
134.804°) of which 2005 unique (Rint = 0.0878, Rsigma = 0.0529),
final R1 [F2>2σ(F2)] = 0.0562, wR2 (all data) = 0.1565. The
crystallographic data is deposited with the Cambridge
Crystallographic Data Centre (CCDC 1533651).
1
Recent reviews: (a) S. Shaaban, S. Liang, N.-W. Liua and G.
Manolikakes, Org. Biomol. Chem., 2017, 15, 1947; (b) N.-W.
Liu, S. Liang and G. Manolikakes, Synthesis, 2016, 48, 1939; (c)
M. Feng, B. Tang, S. H. Liang and X. Jiang, Curr. Top. Med.
Chem., 2016, 16, 1200; (d) J. Drabowicz, P. Kielbasinski, A.
Zajac and P. Wach-Panfilow, in Comprehensive Organic
Conclusions
In present work, we have demonstrated that cyclopropanols
can serve as suitable and easily available starting materials for
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Synthesis, ed. P. Knochel and G. A. Molander, Elsevier:
X.-P. He, Y.-J. Shu, J.-J. Dai, W.-M. Zhang, Y.-S. Feng and H.-J.
X. Shen and M. Dai, Org. Lett., 2015, 17D,O6I0: 1704.1.039/C7OB01605K
View Article Online
Amsterdam, 2nd Ed., 2014, Vol. 6., 131-174; (e) Y. M.
Markitanov, V. M. Timoshenko and Y. G. Shermolovich, J.
Xu, Org. Biomol. Chem., 2015, 13, 7159; (d) Z. Ye, K. E. Gettys,
Sulfur Chem., 2014, 35, 188; (f) D. C. Meadows and J. Gervay- 12 J. K. Cha and O. G. Kulinkovich, Org. React., 2012, 77, 1.
Hague, Med. Res. Rev., 2006, 26, 793.
13 Y. A. Konik, M. Kudrjashova, N. Konrad, S. Kaabel, I. Jarving,
M. Lopp and D. G. Kananovich, Org. Biomol. Chem., 2017, 15
4635.
2
3
(a) S. Patai, Z. Rappoport and C. J. M. Stirling, The Chemistry
of Sulphones and Sulphoxides; Wiley: New York, 1988; (b) M.
Julia, J.-M. Paris, Tetrahedron Lett. 1973, 14, 4833; (c) R. J. K.
Taylor and G. Casy, Org. React. 2004, 62, 359.
,
14 (a) C. Ni and J. Hu, Chem. Soc. Rev. 2016, 45, 5441; (b) T.
Liang, C. N. Neumann and T. Ritter, Angew. Chem. Int. Ed.,
2013, 52, 8214.
For examples, see: (a) H. W. Pinnick and M. A. Reynolds, J.
Org. Chem., 1979, 44, 160; (b) G.-P. Lu, C. Cai, F. Chen, R.-L. Ye 15 Significant amount of benzaldehyde was detected in a crude
and B.-J. Zhou, ACS Sustainable Chem. Eng., 2016,
M. Fernandez, U. Uria, L. Orbe, J. L. Vicario, E. Reyes and L. 16 Examples of radical sulfonylation reactions of unsaturated
Carrillo, J. Org. Chem., 2014, 79, 441; (d) Y. Yang, L. Tang, S. compounds: (a) Y. Jiang and T.-P. Loh, Chem. Sci., 2014,
Zhang, X. Guo, Z. Zha and Z. Wang, Green Chem., 2014, 16
4
, 1804; (c)
reaction mixture.
5
,
,
4939; (b) W. Wei, J. Li, D. Yang, J. Wen, Y. Jiao, J. You and H.
Wang, Org. Biomol. Chem., 2014, 12, 1861; (c) M.-H. Huang,
Y.-L. Zhu, W.-J. Hao, A.-F. Wang, D.-C. Wang, F. Liu, P. Wei,
S.-J. Tu and B. Jiang, Adv. Synth. Catal., 2017, DOI:
4106; (e) Z. Jin, J. Xu, S. Yang, B.-A. Song and Y. R. Chi, Angew.
Chem. Int. Ed., 2013, 52, 12354; (f) B. Sreedhar, M. A. Reddy
and P. S. Reddy, Synlett, 2008, 1949; (g) A. Brandt, A.
Wojtasiewicz, M. Śnieżek and M. Mąkosza, Tetrahedron,
2010, 66, 3378; (h) P. Ciuffreda, S. Casati, L. Alessandrini, G.
Terraneo and E. Santaniello, Steroids, 2003, 68, 733; (i) P.
Bonete and C. Nájera, Tetrahedron, 1995, 51, 2763; (j) S. De
Lombaert and L. Ghosez, Tetrahedron Lett., 1984, 25, 3475;
10.1002/adsc.201700124; (d) A. U. Meyer, K. Straková, T.
Slanina and B. König, Chem. Eur. J., 2016, 22, 8694; (e) X.-W.
Lan, N.-X. Wang, C.-B. Bai, W. Zhang, Y. Xing, J.-L. Wen, Y.-J.
Wang and Y.-H. Li, Sci. Rep., 2015, 5, 18391; doi:
10.1038/srep1839.
(k) J. Otera, T. Mandai, M. Shiba, T. Saito, K. Shimohata, 17 (a) I. Ryu, M. Ando, A. Ogawa, S. Murai and N. Sonoda, J. Am.
K.Takamori and Y.Kawasaki , Organometallics, 1983,
2
, 332. (l)
Chem. Soc., 1983, 105, 7192; (b) I. Ryu, K. Matsumoto, Y.
Kameyama, M. Ando, N. Kusumoto, A. Ogawa, N. Kambe, S.
Murai and N. Sonoda, J. Am. Chem. Soc., 1993, 115, 12330;
(c) E. Hasegawa, K. Nemoto, R. Nagumo, E. Tayama and H.
Iwamoto, J. Org. Chem., 2016, 81, 2692.
W. Keim, J. Herwig and G. Pelzer, J. Org. Chem., 1997, 62, 422.
(a) G. L. Khatik, R. Kumar and A. K. Chakraborti, Org. Lett.,
4
5
2006,
8, 2433; (b) N. K. Rana, S. Selvakumar and V. K. Singh, J.
Org. Chem., 2010, 75, 2089; (c) D. Enders, K. Lüttgen and A. A.
Narine, Synthesis 2007, 959; (d) J. S. Yadav, B. V. S. Reddy and 18 J. T. B. H. Jastrzebski and G. van Koten, in Modern
G. Baishya, J. Org. Chem., 2003, 68, 7098.
Organocopper Chemistry, ed. N. Krause, Wiley-VCH:
Weinheim, 2002, 1-44.
(a) E. Voutyritsa, I. Triandafillidi and C. G. Kokotos, Synthesis,
2017, 49, 917; (b) M. Jegelka and B. Plietker, Chem. Eur. J., 19 J. K. Kochi, J. Am. Chem. Soc., 1963, 85, 1958.
2011, 17, 10417; (c) N. K. Jana and J. G. Verkade, Org. Lett., 20 Formation of enones by copper-catalyzed oxidation of
2003,
5
, 3787; (d) M. Kirihara, A. Itou, T. Noguchi and J.
cyclopropanols: (a) L.-Z. Li, B. Xiao, Q.-X. Guo and S. Xue,
Tetrahedron, 2006, 62, 7762; (b) E. Hasegawa, M. Tateyama,
R. Nagumo, E. Tayama and H. Iwamoto, Beilstein J. Org.
Yamamoto, Synlett, 2010, 1557; (e) A. Shaabani, P. Mirzaei, S.
Naderi and D. G. Lee, Tetrahedron, 2004, 60, 11415.
A. Bhunia, S. R. Yetra, S. S. Bhojgude and A. T. Biju, Org. Lett.,
2012, 14, 2830.
6
7
8
9
Chem., 2013, 9, 1397.
21 Regioselective ring-opening at the least substituted C1-C3
M. Vellakkaran, M. M. S. Andappan, K. Nagaiah and J. B.
Nanubolu, Eur. J. Org. Chem., 2016, 21, 3575.
G. Fang, J. Liu, W. Shang, Q. Liu and X. Bi, Chem. Asian J., 2016,
11, 3334.
bond of the cyclopropane 14 supports electrophilic attack of
Cu(II) and formation of β-copper(II) ketone
A
as initial step,17
since an alternative radical pathway would result in scissoring
of C1-C2 bond. See for example: W.-B. Han, S.-G. Li, X.-W. Lu
and Y. Wu, Eur. J. Org. Chem., 2014, 3841.
Recent reviews: (a) A. Nikolaev and A. Orellana, Synthesis
2016, 48, 1741; (b) I. Haym and M. A. Brimble, Org. Biomol. 22 (a) N. A. Meanwell, J. Med. Chem., 2011, 54, 2529; (b) (c) G.
Chem. 2012, 10, 7649; (c) O. Kulinkovich, Eur. J. Org. Chem.,
A. Patani and E. J. LaVoie, Chem. Rev., 1996, 96, 3147; (d) N.
K. Konduru, S. Dey, M. Sajid, M. Owais and N. Ahmed, Eur. J.
Med. Chem. 2013, 59, 23; (e) C. Curti, M. Laget, A. Ortiz
Carle, A. Gellis and P. Vanelle, Eur. J. Med. Chem., 2007, 42,
880.
2004, 4517; (d) O. G. Kulinkovich, Chem. Rev., 2003, 103
2597.
,
10 Recent examples: (a) G. Z. Elek, V. Borovkov, M. Lopp and
D. G. Kananovich, Org. Lett., 2017, 19, 3544; (b) Y.-S. Feng, Y.-
J. Shu, P. Cao, T. Xu and H.-J. Xu, Org. Biomol. Chem., 2017, 15
,
23 X. Jie, Y. Shang, X. Zhang and W. Su, J. Am. Chem. Soc., 2016,
138, 5623.
3590; (c) N. Tumma, E. Gyanchander and J. K. Cha, J. Org.
Chem., 2017, 82, 4379; (d) S.-C. Lu, H.-S. Li, S. Xu and G.-Y.
Duan, Org. Biomol. Chem., 2017, 15, 324; (e) D. C. Davis, C. W.
Haskins and M. Dai, Synlett, 2017, 28, 913; (f) H. Zhang, G. Wu,
H. Yi, T. Sun, B. Wang, Y. Zhang, G. Dong and J. Wang, Angew.
Chem. Int. Ed., 2017, 56, 3945; (g) X. Zhou, Z. Qi, S. Yu, L. Kong,
Y. Li, W.-F. Tian and X. Li, Adv. Synth. Catal., 2017, 359, 1620;
(h) X. Zhou, S. Yu, L. Kong and X. Li, ACS Catalysis, 2016, 6, 647;
(i) D. C. Davis, K. L. Walker, C. Hu, R. N. Zare, R. M. Waymouth
and M. Dai, J. Am. Chem. Soc., 2016, 138, 10693; (k) M.-H.
Shen, X.-L. Lu and H.-D. Xu, RSC Adv., 2015, 5, 98757; (l) S.
Wang, L.−N. Guo, H. Wang and X.-H. Duan, Org. Lett., 2015,
17, 4798; (m) R. V. N. S. Murali, N. N. Rao and J. K. Cha, Org.
Lett., 2015, 17, 3854.
11 (a) D. G. Kananovich, Y. A. Konik, D. M. Zubrytski, I. Järving and
M. Lopp, Chem. Commun., 2015, 51, 8349; (b) Y. Li, Z. Ye, T.
M. Bellman, T. Chi and M. Dai, Org. Lett., 2015, 17, 2186; (c)
6 | J. Name., 2012, 00, 1-3
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