Catalyst-controlled highly selective coupling and oxygenation of olefins: A direct approach to alcohols, ketones, and diketones

Article abstract of DOI:10.1002/anie.201303917

Oxygen? That's radical! A method for the direct synthesis of substituted alcohols, ketones, and diketones through a catalyst-controlled highly chemoselective coupling and oxygenation of olefins has been developed. The method is simple and practical, can be switched by the selection of different catalysts, and employs molecular oxygen as both an oxidant and a reagent. Copyright

Full text of DOI:10.1002/anie.201303917

.
Angewandte
Communications
DOI: 10.1002/anie.201303917
Dioxygen Activation
Catalyst-Controlled Highly Selective Coupling and Oxygenation of
Olefins: A Direct Approach to Alcohols, Ketones, and Diketones**
Yijin Su, Xiang Sun, Guolin Wu, and Ning Jiao*
Radical reactions play a very important role in many areas of
organic chemistry and polymer chemistry.[1,2] In the past
decades, the development of a catalytic system to initiate
radical intermediates under mild conditions and to make
radical reactions more controllable have been of continuous
interest. Among them, transition-metal catalysis has proven
to be one of the most highly efficient strategies.[3] Moreover,
owing to their low cost, availability, stability, and environ-
mentally friendly nature, copper[4] and iron[5] catalysts have
been extensively investigated in radical reactions, and present
an attractive prospect for organic synthesis.
Molecular oxygen has been thought of as an ideal oxidant
and an atom-efficient reagent in synthetic chemistry.[6]
Combining the above two concepts, the Cu- and/or Fe-
catalyzed radical addition and oxygenation of alkenes for the
synthesis of carbonyl complexes, employing molecular oxygen
as the oxygen source, have been significantly developed.[7–9]
Zhu and co-workers reported a Cu- catalyzed intramolecular
dehydrogenative aminooxygenation started by the addition
process of a N-radical intermediate to alkenes (Scheme 1a).[7]
The copper-catalyzed intramolecular relay of a C-radical
addition to alkenes that is then captured by molecular oxygen
Scheme 1. Catalyst-controlled oxygenation of alkenes.
was achieved by the group of Chiba (Scheme 1b).[8] Ji and co-
workers realized a copper and iron cocatalyzed intermolec-
ular oxyphosphorylation of alkenes initiated by a P radical
(Scheme 1c).[9] Furthermore, by using hydrazines as the
substrates, which are reported as practical radical precur-
sors,[10] The group of Taniguchi and Ishibashi disclosed an
efficient approach to alcohols by the similar radical process
(Scheme 1d).[11,12] Despite the significance of these reactions,
this kind of radical oxygenation is still limited, and it remains
challenging to control the selectivity from the same starting
materials. Herein, we describe a novel catalyst-controlled
highly chemoselective coupling and oxygenation of alkenes
for the direct synthesis of alcohols, ketones, and diketones
(Scheme 1e), which are important synthons in organic
chemistry, important ligands, and biologically active com-
pounds.[13,14]
Our hypothesis of triggering a tandem radical addition/
oxygenation sequence started by investigating the reaction of
phenyl hydrazine (1a) with styrene (2a) (Table 1). Initially,
38% of 3a was obtained, along with a trace amount of
diketone 4a, in the absence of any catalyst in acetonitrile
(entry 1). When iPr2NEt was used as base, 3a was obtained in
48% yield (entry 2). When 1,4-diazabicyclo[2.2.2]octane
(DABCO) was used as a base instead of iPr2NEt, the yield
of 3a increased to 55% (entry 3). Other solvents, such as
toluene or dimethylformamide (DMF), were not effective
(entries 4 and 5). Significantly, 3a was isolated in 74% yield
when the loading of anhydrous DABCO was reduced to
40 mol% in the presence of 2.0 equivalents of H2O as an
additive (entry 6).
To our delight, a 23% yield of 1,2-diarylethane-dione (4a)
was obtained when Cu(OTf)2 was employed as the catalyst
(Table 1, entry 7). 4a was produced in 49% yield by decreas-
ing the loading of copper(II) catalyst at room temperature
(entry 8). The yield of 4a decreased to 20%, along with the
formation of 3a (38%), when the weaker base (NH4)2CO3
[*] Y. Su,[+] X. Sun,[+] G. Wu, Dr. N. Jiao
State Key Laboratory of Natural and Biomimetic Drugs, School of
Pharmaceutical Sciences, Peking University
Xue Yuan Rd. 38, Beijing 100191 (China)
E-mail: jiaoning@bjmu.edu.cn
Dr. N. Jiao
Shanghai Key Laboratory of Green Chemistry and Chemical
Processes, East China Normal University
Shanghai 200062 (China)
[+] These authors contributed equally to this work.
[**] Financial support from the National Basic Research Program of
China (973 Program 2009CB825300), the National Science Foun-
dation of China (21172006), and Peking University is greatly
appreciated. We thank Zejun Xu for reproducing the results for 3j,
4i, and 5e.
Supporting information for this article is available on the WWW
under http://dx.doi.org/10.1002/anie.201303917.
9808
ꢀ 2013 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Angew. Chem. Int. Ed. 2013, 52, 9808 –9812

Angewandte
Chemie
Table 1: Optimization of reaction conditions.[a]
Entry Cat. (mol%)
Base (equiv)
T
[8C]
3a[b] 4a[b] 5a[b]
[%] [%] [%]
1
2
3
none
none
none
none
none
none
none
80
80
80
38 trace
48 trace
55 trace
0
0
0
0
0
0
iPr2Net (2.0)
DABCO (2.0)
DABCO (2.0)
DABCO (2.0)
DABCO (0.4)
4[c]
5[d]
6[e]
80 trace trace
80
80
43 trace
82 trace
(74)
7
8
9
10
11
Cu(OTf)2 (10)
Cu(OTf)2 (2)
Cu(OTf)2 (2)
Cu(OTf)2 (2)
Cu(OTf)2 (1)
DABCO (0.4)
DABCO (0.4)
(NH4)2CO3 (2.0) 25
none
DABCO (1.5)
70
25
0
23
49
20
0
65
0
0
0
0
0
0
38
55
0
25
25
Fe(NO)3·9H2O (7.5)
(43)
39
Scheme 2. Transition-metal-free selective synthesis of 1,2-diaryletha-
none. For reaction Conditions, see Table 1, entry 6. Yields shown are of
isolated products.
12[f] Cu(OTf)2 (1)
DABCO (1.5)
25
0
0
Fe(NO)3·9H2O (7.5)
13[g] Cu(OTf)2 (3)
DABCO (3.2)
0
0
72
0
Fe(NO)3·9H2O (7.5)
(70)
14[h] TBAI (10)
15[h] TBAI (10)
16[h] I2 (10)
DABCO (1.5)
pyridine (0.2)
pyridine (0.2)
70 trace trace (35)
70 trace trace (41)
70 trace trace (25)
[a] Reaction Conditions: 2a (2.5 mmol), catalyst, base, and additives
were added in CH3CN (4 mL) under O2 (1 atm), followed by the addition
of 1a (0.5 mmol). [b] Yields determined by GC analysis; yields of isolated
products are shown in parentheses. [c] The reaction was carried out in
toluene. [d] The reaction was carried out in DMF. [e] H2O (2.0 equiv) was
added. [f] TBAB (0.1 equiv) was added. [g] 4-methoxyaniline (2.0 equiv)
was added. [h] 2a (0.5 mmol), 1a (1.0 mmol). A mixture of CH3CN
(0.5 mL) and H2O (1.5 mL) was used as the solvent.
was employed (entry 9). In the absence of a base, 4a was not
detected, but rather 3a was obtained in 55% yield (entry 10).
Gratifyingly, the expected diketone product 4a was isolated in
70% yield when Cu(OTf)2 (3 mol%) and Fe(NO3)3·9H2O
(7.5 mol%) were used as cocatalysts[15] at 08C (entry 13). The
use of tetrabutylammonium bromide (TBAB; 10 mol%) as
a phase transfer catalyst did not improve the efficiency of this
transformation (entry 12).
Scheme 3. Cu- and Fe-cocatalyzed selective synthesis of 1,2-diaryl-
ethane-dione. For reaction Conditions, see Table 1, entry 13. Yields
shown are of isolated products.
The alcohol product 5a was selectively obtained in 35%
yield when the reaction was carried out in the presence of
catalytic amount of tetrabutylammonium iodide (TBAI;
entry 14, Table 1). After screening different parameters, the
standard conditions for the selective alcohol synthesis were
determined to be: TBAI (10 mol%), pyridine (20 mol%),
a mixture of CH3CN (0.5 mL) and H2O (1.5 mL) as solvent,
O2 (1.0 atm), 708C, under which, alcohol 5a was obtained in
41% yield (entry 15).
With the optimal reaction conditions in hand, we sub-
sequently investigated the substrate scope of this highly
selective method (Schemes 2, 3 and 4). The transition-metal-
free aerobic oxidative coupling of aryl hydrazines and
substituted styrenes is summarized in Scheme 2. Not only
electron-rich groups, such as p-methyl (3b) and m-methyl
(3d), but also electron-deficient groups, such as m-CF3 (3h)
on the aryl ring of the aryl hydrazines could drive the reaction
smoothly in moderate yield. Halo-substituted aryl hydrazines
also performed well under the standard conditions, generating
the halo-substituted products. Moreover, this transformation
proceeded smoothly and in moderate yields with electron-rich
styrenes that contain electron-donating groups, such as p-
methyl (3i), p-tert-butyl (3j), p-methoxy (3k), p-ethoxy (3l)
and m-methyl (3n), on the aryl ring. Substituted styrenes with
electron-withdrawing groups are also tolerated in this trans-
formation (3m, 3o, and 3p).
Furthermore, under copper and iron cocatalyzed condi-
tions, various 1,2-diarylethane-diones were obtained in mod-
erate yields from corresponding aryl hydrazines and substi-
tuted styrenes (Scheme 3). Aryl hydrazines bearing electron-
withdrawing groups such as CF3 (4c and 4g) performed well,
giving yields of 59% and 49%, respectively. Halo-substituted
Angew. Chem. Int. Ed. 2013, 52, 9808 –9812
ꢀ 2013 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.angewandte.org 9809

.
Angewandte
Communications
used (Eqs. (S3) and (S5); determined by HRMS). Reaction in
the presence of H218O under 16O2 (1 atm) afford 4a and 5b
without the formation of [18O]4a and [18O]5b (Eqs. (S4) and
(S6); determined by HRMS). These isotopic labeling results
clearly demonstrate that the oxygen atoms of 3a, 4a, and 5b
originated from O2. Furthermore, when the reaction mixture
was analyzed by GCMS, we found that 1a was converted into
3a after 15 min. After 16 h, 4a was completely produced from
3a. This result indicated that the formation of 4a is a relay
process with 3a as the intermediate.
On the basis of the above results and previous work,
a proposed mechanism for the selective coupling and oxy-
genation of alkenes and hydrazines is shown in Scheme 5. As
previously reported,[10a] phenyl radical 8 and a large amount
of hydroperoxyl radical (HOO·) are initially generated from
1a and oxygen with the release of N2 in the presence of base.
These transformations go faster when high-oxidation-value
transition-metal salts (CuII and FeIII)[11,12,17] or iodine[18] are
used as oxidants. The key intermediate 10 is provided by the
formation of 9 and its subsequent addition to oxygen.[17a] In
a transition-metal- and iodine-free system, the benzyl peroxy
radical 10 couples with the hydroperoxide radical (HOO·) to
form a monoalkyl tetroxide 11, which decomposes to afford
the desired product 3a, along with the formation of molecular
oxygen and water through Russell fragmentation.[19] On the
other hand, because of the low concentration of hydro-
peroxide radical in the Cu- and Fe- cocatalytic system,[20] 3a is
generated through intermediate 12 followed by elimination of
CuOH.[21] Furthermore, intermediate 13, which is generated
from 3a, could be continuously oxidized by Cu- and/or Fe-
salts and molecular oxygen to form benzyl radical 14, which
can undergo the same oxidative processes again (as benzyl
radical 9) to form the second carbonyl group of diketone
product 4a. In the TBAI catalytic pathway, with a low
concentration of hydroperoxide radical, intermediate 10
abstracts a H atom from the strong H-donor 6 to provide
hydroperoxide 15, along with the formation of radical
intermediate 7 to complete the chain propagation step.
Subsequently, the hydroxylation product 5a is afforded by
Scheme 4. TBAI catalyzed selective synthesis of alcohols. For reaction
Conditions, see Table 1, entry 15. Yields shown are of isolated prod-
ucts.
products 4d, 4e, 4 f, and 4h were also obtained in moderate to
good yield. Styrenes bearing electron-withdrawing and elec-
tron-donating substituents at the aryl ring can be efficiently
transformed into the corresponding diketone products.
When using TBAI, various 1,2-diarylethanols were
obtained in moderate to good yields from the corresponding
aryl hydrazines and substituted styrenes (Scheme 4). The
reaction with cyclohexylhydrazine also works under these
conditions, but with low yield (5h). Furthermore, allylben-
zene and multi-substituted styrene were tolerated in this
transformation, forming the corresponding alcohols (5s and
5t)[16] in 38% and 28% yield, respectively. Therefore,
substituted alcohols, ketones, and diketones can be prepared
by this this aerobic coupling and oxygenation strategy in
a
highly
chemoselective
manner from the same
simple olefins by selecting
a different catalyst.
To further understand
these transformations, control
experiments with 18O2 and
H218O isotopic labeling were
investigated. It was found that
the oxygen of the newly
formed carbonyl group of
1,2-diarylethanone 3a was
wholly from oxygen molecu-
lar, rather than from H2O
(Supporting
Information,
Eqs. (S1) and (S2); deter-
mined by HRMS). On the
other hand, [18O]4a and
[18O]5b were obtained when
18O2 (1 atm) and H216O were Scheme 5. Proposed mechanism.
9810 www.angewandte.org
ꢀ 2013 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Angew. Chem. Int. Ed. 2013, 52, 9808 –9812

Angewandte
Chemie
Chem. 2008, 120, 3363; Angew. Chem. Int. Ed. 2008, 47, 3317;
hydroperoxide 15 through Landolt reaction with the regen-
eration of iodine.[22,23] The by-products benzene,[10a] bibenzyl,
and stilbene[24] were detected by GCMS, which indicated that
intermediates 8 and 9 are involved in this transformation.
In summary, we have developed a novel catalyst-con-
trolled highly chemoselective coupling and oxygenation of
olefins for the direct synthesis of substituted alcohols,
ketones, and diketones. Molecular oxygen not only partic-
ipates as an oxidant, but also undergoes dioxygen activation
through a radical process. The selectivity for the synthesis of
substituted alcohols, ketones, and diketones, which are
important synthons, important ligands, and biologically
active compounds, is readily switched by the selection of
different catalysts. Further studies on the mechanism and
synthetic application of these reactions are ongoing in our
group.
d) A. Fꢁrstner, Angew. Chem. 2009, 121, 1390; Angew. Chem.
Int. Ed. 2009, 48, 1364; e) A. O. Sarhan, C. Bolm, Chem. Soc.
Rev. 2009, 38, 2730.
[6] For some reviews on reactions using molecular oxygen as an
oxidant, see: a) S. S. Stahl, Science 2005, 309, 1824; b) S. S. Stahl,
Angew. Chem. 2004, 116, 3480; Angew. Chem. Int. Ed. 2004, 43,
3400; c) B. M. Stoltz, Chem. Lett. 2004, 33, 362; d) M. J. Schultz,
M. S. Sigman, Tetrahedron 2006, 62, 8227; e) J. Muzart, Chem.
Asian J. 2006, 1, 508; f) M. S. Sigman, D. R. Jensen, Acc. Chem.
Res. 2006, 39, 221; g) E. M. Beccalli, G. Broggini, M. Martinelli,
S. Sottocornola, Chem. Rev. 2007, 107, 5318; h) J. Piera, J. E.
Bꢀckvall, Angew. Chem. 2008, 120, 3558; Angew. Chem. Int. Ed.
2008, 47, 3506; i) T. Punniyamurthy, S. Velusamy, J. Iqbal, Chem.
Rev. 2005, 105, 2329; j) Z. Shi, C. Zhang, C. Tang, N. Jiao, Chem.
Soc. Rev. 2012, 41, 3381.
[7] H. Wang, Y. Wang, D. Liang, L. Liu, J. Zhang, Q. Zhu, Angew.
Chem. 2011, 123, 5796; Angew. Chem. Int. Ed. 2011, 50, 5678.
[8] K. K. Toh, Y.-F. Wang, E. P. J. Ng, S. Chiba, J. Am. Chem. Soc.
2011, 133, 13942.
[9] W. Wei, J.-X. Ji, Angew. Chem. 2011, 123, 9263; Angew. Chem.
Int. Ed. 2011, 50, 9097.
Received: May 7, 2013
Published online: July 24, 2013
[10] a) F. D. Chattaway, J. Chem. Soc. Trans. 1907, 91, 1323; for other
oxidants, see: b) R. L. Hardie, R. H. Thomson, J. Chem. Soc.
1957, 2512; c) F. L. Scott, J. A. Barry, Tetrahedron Lett. 1968, 9,
2461; d) E. S. Huyser, R. H. S. Wang, J. Org. Chem. 1968, 33,
3901; e) P. C. Huang, E. M. Kosower, J. Am. Chem. Soc. 1968, 90,
2367; f) E. M. Kosower, P. C. Huang, T. Tsuji, J. Am. Chem. Soc.
1969, 91, 2325; g) H. A. O. Hill, P. J. Thornalley, FEBS Lett.
1981, 125, 235; h) E. J. Corey, A. W. Gross, J. Org. Chem. 1985,
50, 5391; i) R. Braslau, L. C. Burrill II, L. K. Mahal, T. Wedek-
ing, Angew. Chem. 1997, 109, 247; Angew. Chem. Int. Ed. Engl.
1997, 36, 237; j) N. Naik, R. Braslau, Tetrahedron 1998, 54, 667;
k) R. Braslau, N. Naik, H. Zipse, J. Am. Chem. Soc. 2000, 122,
8421; l) R. Braslau, L. C. Burrill, M. Siano, N. Naik, R. K.
Howden, L. K. Mahal, Macromolecules 1997, 30, 6445; m) D.
Benoit, V. Chaplinski, R. Braslau, C. J. Hawker, J. Am. Chem.
Soc. 1999, 121, 3904; n) T. Taniguchi, A. Idota, S. Yokoyama, H.
Ishibashi, Tetrahedron Lett. 2011, 52, 4768; o) T. Taniguchi, A.
Idota, H. Ishibashi, Org. Biomol. Chem. 2011, 9, 3151. For
another example of intermolecular aryl radical addition, the
Meerwein arylation, see: p) H. Meerwein, E. Buchner, K.
van Emster, J. Prakt. Chem. 1939, 152, 237.
[11] a) T. Taniguchi, Y. Sugiura, H. Zaimoku, H. Ishibashi, Angew.
Chem. 2010, 122, 10352; Angew. Chem. Int. Ed. 2010, 49, 10154;
b) T. Taniguchi, H. Zaimoku, H. Ishibashi, Chem. Eur. J. 2011,
17, 4307.
[12] For hydroxylations from other carbon radical precursors, see:
a) T. Iwahama, S. Sakaguchi, Y. Ishii, Chem. Commun. 2000, 613;
b) K. Hirano, T. Iwahama, S. Sakaguchi, Y. Ishii, Chem.
Commun. 2000, 2457; c) T. Hara, T. Iwahama, S. Sakaguchi, Y.
Ishii, J. Org. Chem. 2001, 66, 6425; d) Y. Nobe, K. Arayama, H.
Urabe, J. Am. Chem. Soc. 2005, 127, 18006.
[13] a) L. Wçhler, J. von Liebig, Ann. Pharm. 1832, 3, 249; b) A. J.
Lapworth, J. Chem. Soc. Trans. 1904, 85, 1206; c) J. Tsuji,
Transition Metal Reagents and Catalysts, Wiley, New York, 2004;
d) F. Diederich, P. J. Stang, Metal-Catalyzed Cross-Coupling
Reactions, Wiley-VCH, Weinheim, 1998; e) A. de Meijere, F.
Diederich, Metal-Catalyzed Cross-Coupling Reactions, 2nd ed.,
Wiley, Weinheim, 2004; f) M. Hudlicky in Oxidations in Organic
Chemistry, ACS Monograph 186, American Chemical Society,
Washington, DC, 1990; g) G. Olah, Friedel – Crafts and Related
Reactions, Vol. III, Interscience, New York, 1964, p. 1259.
[14] a) K. Fitzi, Ger. Pat. 2221546, 1972; US Pat. 3929807, 1975
[Chem. Abstr. 1973, 78, 58428]; b) C. A. Buehler, J. O. Harris,
W. F. Arendale, J. Am. Chem. Soc. 1950, 72, 4953; c) N. S.
Kozlov, G. S. Shmanal, Chem. Heterocycl. Compd. 1974, 10, 974;
Keywords: copper · dioxygen activation · iodine · ketones ·
radical reactions
.
[1] For reviews, see: a) Radicals in Organic Synthesis: Formation of
Carbon-Carbon Bonds (Ed.: B. Giese), Pergamon, Oxford,
1986; b) Stereochemistry of Radical Reactions (Eds.: D. P.
Curran, N. A. Porter, B. Giese), Wiley-VCH, Weinheim, 1996;
c) Radicals in Organic Synthesis (Eds.: P. Renaud, M. P. Sibi),
Wiley-VCH, Weinheim, 2001; d) Radicals in Synthesis I and II,
Vols. 263 – 264 of Topics in Current Chemistry (Ed.: A. Gansꢀ-
uer), Springer, Berlin, 2006.
[2] For recent reviews, see: a) C. Chatgilialoglu, D. Crich, M.
Komatsu, I. Ryu, Chem. Rev. 1999, 99, 1991; b) A. Gansꢀuer, H.
Bluhm, Chem. Rev. 2000, 100, 2771; c) T. R. Rheault, M. P. Sibi,
Synthesis 2003, 803; d) M. P. Sibi, S. Manyem, J. Zimmerman,
Chem. Rev. 2003, 103, 3263.
[3] For recent reviews, see: a) W. C. Trogler, Organometallic Radical
Processes, Elsevier, Amsterdam, 1990, Chap. 3, 4, 9, 10; b) D.
Astruc, Acc. Chem. Res. 1991, 24, 36; c) D. Astruc, Electron
Transfer and Radical Processes in Transition-Metal Chemistry,
VCH, New York, 1995, Chap. 3, 5, 6; d) K. E. Torraca, L.
McElwee-White, Coord. Chem. Rev. 2000, 206 – 207, 469;
e) J. M. R. Narayanam, C. R. J. Stephenson, Chem. Soc. Rev.
2011, 40, 102.
[4] a) C. Zhang, C. Tang, N. Jiao, Chem. Soc. Rev. 2012, 41, 3464; for
some very recent examples, see: b) K. K. Toh, S. Sanjaya, S.
Sahnoun, S. Y. Chong, S. Chiba, Org. Lett. 2012, 14, 2290; c) X.-
F. Xia, L.-L. Zhang, X.-R. Song, X.-Y. Liu, Y.-M. Liang, Org.
Lett. 2012, 14, 2480; d) C. Zhang, X. Zong, L. Zhang, N. Jiao,
Org. Lett. 2012, 14, 3280; e) Y. L. Tnay, C. Chen, Y. Y. Chua, L.
Zhang, S. Chiba, Org. Lett. 2012, 14, 3550; f) Y.-F. Wang, H.
Chen, X. Zhu, S. Chiba, J. Am. Chem. Soc. 2012, 134, 11980; g) T.
Sonobe, K. Oisaki, M. Kanai, Chem. Sci. 2012, 3, 3249; h) S.
Mizuta, O. Galicia-Lopez, K. M. Engle, S. Verhoog, K. Wheel-
house, G. Rassias, V. Gouverneur, Chem. Eur. J. 2012, 18, 8583;
i) W. Zhou, Y. Liu, Y. Yang, G.-J. Deng, Chem. Commun. 2012,
48, 10678; j) W. Zhou, Y. Yang, Y. Liu, G.-J. Deng, Green Chem.
2013, 15, 76; k) K. Hirano, M. Miura, Chem. Commun. 2012, 48,
10704.
[5] For reviews on iron-mediated reactions, see: a) Catalysis in
Organic Chemistry (Ed.: B. PlietkerIron), Wiley-VCH, Wein-
heim, 2008; b) A. Correa, O. G. MancheÇo, C. Bolm, Chem. Soc.
Rev. 2008, 37, 1108; c) S. Enthaler, K. Junge, M. Beller, Angew.
Angew. Chem. Int. Ed. 2013, 52, 9808 –9812
ꢀ 2013 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.angewandte.org
9811

.
Angewandte
Communications
d) T. E. Barta, M. A. Stealey, P. W. Collins, R. M. Weier, Bioorg.
Med. Chem. Lett. 1998, 8, 3443; e) L. L. Chang, K. L. Sidler,
M. A. Cascieri, S. de Laszlo, G. Koch, B. Li, M. MacCoss, N.
Mantlo, S. OꢂKeffe, M. Pang, A. Rolando, W. K. Hagmann,
Bioorg. Med. Chem. Lett. 2001, 11, 2549; f) C. A. Buehler, J. W.
Addleburg, D. M. Glenn, J. Org. Chem. 1955, 20, 1350; g) M. R.
Rohman, I. Kharkongor, M. Rajbangshi, H. Mecadon, B. M.
Laloo, P. R. Sahu, I. Kharbangar, B. Myrboh, Eur. J. Org. Chem.
2012, 320; h) P. Espinet, M. A. Esteruelas, L. A. Oro, J. L.
Berrano, E. Solo, Coord. Chem. Rev. 1992, 117, 215; i) R. M.
Wadkins, J. L. Hyatt, X. Wei, K. J. P. Yoon, M. Wierdl, C. C.
Edwards, C. L. Morton, J. C. Obennauer, K. Damodaran, P.
Beroza, M. K. Danks, P. M. Potter, J. Med. Chem. 2005, 48, 2906.
[15] For a review on Cu- and Fe-cocatalyzed reactions, see: Y. Su, W.
Jia, N. Jiao, Synthesis 2011, 1678.
[16] 5t was obtained as a pure compound, no isomers were detected.
[17] a) T. Varea, M. E. Gonzlez-Nunez, J. Rodrigo-Chiner, G.
Asensio, Tetrahedron Lett. 1989, 30, 4709; b) J. B. Aylward, J.
Chem. Soc. C 1969, 1663; c) R. Nakajima, M. Kinosada, T.
Tamura, T. Hara, Bull. Chem. Soc. Jpn. 1983, 56, 1113; d) A. S.
Demir, ꢃ. Reis, E. ꢃzgꢁl-Karaaslan, J. Chem. Soc. Perkin Trans.
1 2001, 3042; e) A. S. Demir, ꢃ. Reis, M. Emrullahoglu,
Tetrahedron 2002, 58, 8055; f) Z.-X. Chen, G.-W. Wang, J. Org.
Chem. 2005, 70, 2380; g) G.-W. Wang, Y.-M. Lu, Z.-X. Chen,
Org. Lett. 2009, 11, 1507.
V. Nardello-Rataj, J. Aubry, C. Kazaz, J. Org. Chem. 2009, 74,
4560.
[20] A small amount of hydroperoxide radical was generated by
transition metal catalyzed oxidation, and CuI and FeII can
destroy the hydroperoxide radical through Fenton chemistry:
a) H. J. H. Fenton, Chem. News 1876, 190; b) H. J. H. Fenton, J.
Chem. Soc. 1894, 65, 899.
[21] H. R. Lucas, L. Li, A. A. Narducci Sarjeant, M. A. Vance, E. I.
Solomon, K. D. Karlin, J. Am. Chem. Soc. 2009, 131, 3230.
[22] a) H. Landolt, Ber. Dtsch. Chem. Ges. 1886, 19, 1317; b) A. P.
Oliveira, R. B. Faria, J. Am. Chem. Soc. 2005, 127, 18022.
[23] For selected examples of TBAI and organic hydroperoxide
systems in organic chemistry, see: a) M. Uyanik, H. Okamoto, T.
Yasui, K. Ishihara, Science 2010, 328, 1376; b) Z. J. Liu, J. Zhang,
S. L. Chen, E. Shi, Y. Xu, X. B. Wan, Angew. Chem. 2012, 124,
3285; Angew. Chem. Int. Ed. 2012, 51, 3231; c) L. Chen, E. Shi,
Z. J. Liu, S. L. Chen, W. Wei, H. Li, K. Xu, X. B. Wan, Chem.
Eur. J. 2011, 17, 4085; d) W. Wei, C. Zhang, Y. Xu, X. B. Wan,
Chem. Commun. 2011, 47, 10827; e) W.-P. Mai, H.-H. Wang, Z.-
C. Li, J.-W. Yuan, Y.-M. Xiao, L.-R. Yang, P. Mao, Chem.
Commun. 2012, 48, 10117; f) M. Uyanik, D. Suzuki, T. Yasui, K.
Ishihara, Angew. Chem. Int. Ed. 2011, 50, 5331; g) T. Froehr, C. P.
Sindlinger, U. Kloeckner, P. Finkbeiner, B. J. Nachtsheim, Org.
Lett. 2011, 13, 3754; h) L. Ma, X. Wang, W. Yu, B. Han, Chem.
Commun. 2011, 47, 11333; i) R.-Y. Tang, Y.-X. Xie, Y.-L. Xie, J.-
N. Xiang, J.-H. Li, Chem. Commun. 2011, 47, 12867; j) J. Xie, H.
Jiang, Y. Cheng, C. Zhu, Chem. Commun. 2012, 48, 979; k) A.
Yoshimura, K. R. Middleton, C. Zhu, V. N. Nemykin, V. V.
Zhdankin, Angew. Chem. 2012, 124, 8183; Angew. Chem. Int. Ed.
2012, 51, 8059; l) Y. Yan, Y. Zhang, C. Feng, Z. Zha, Z. Wang,
Angew. Chem. 2012, 124, 8201; Angew. Chem. Int. Ed. 2012, 51,
8077.
[18] For selected reactions of iodine and hydrazine, see: a) P. Lumme,
P. Lahermo, J. Tummavuori, Acta Chem. Scand. 1965, 19, 2175;
b) J. N. Cooper, R. W. Ramette, J. Chem. Educ. 1969, 46, 872;
c) R. M. Liu, D. W. Margerum, Inorg. Chem. 1998, 37, 2531.
[19] a) G. A. Russell, J. Am. Chem. Soc. 1957, 79, 3871; b) J. A.
Howard, K. U. Ingold, J. Am. Chem. Soc. 1968, 90, 1058; c) M.
Nakano, K. Takayama, Y. Shimizu, Y. Tsuji, H. Inaba, T. Migita,
J. Am. Chem. Soc. 1976, 98, 1974; d) S. Riyas, G. Krishnan, P. N.
Mohan, J. Braz. Chem. Soc. 2008, 19, 1023; e) M. Catir, H. Kilic,
[24] M.-K. Zhu, J.-F. Zhao, T.-P. Loh, Org. Lett. 2011, 13, 6308.
9812
www.angewandte.org
ꢀ 2013 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Angew. Chem. Int. Ed. 2013, 52, 9808 –9812