Organoselenium-catalyzed mild dehydration of aldoximes: An unexpected practical method for organonitrile synthesis

Article abstract of DOI:10.1021/ol500075h

Areneselenenic acids (ArSeOH), readily generated from diaryl diselenides and H₂O₂ by in situ oxidation, were found to be effective and reusable catalysts for dehydration of aldoximes, leading to a practical and scalable preparation of useful organonitriles under mild conditions.

Full text of DOI:10.1021/ol500075h

Letter
pubs.acs.org/OrgLett
Organoselenium-Catalyzed Mild Dehydration of Aldoximes: An
Unexpected Practical Method for Organonitrile Synthesis
,†,‡,§
Hongyan Li, Xu Zhang, Jianqing Ye, Jianping Liu, Qing Xu,* and Mark Lautens§
‡
†,‡
‡
†
,†,‡
Lei Yu,*
†Zhejiang Key Laboratory of Carbon Materials, College of Chemistry and Materials Engineering, Wenzhou University, Wenzhou,
Zhejiang 325035, China
‡
School of Chemistry and Chemical Engineering, Yangzhou University, Yangzhou, Jiangsu 225002, China
§
Davenport Chemistry Laboratories, Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, ON M5S 3H6,
Canada
*
S Supporting Information
ABSTRACT: Areneselenenic acids (ArSeOH), readily generated from diaryl diselenides and H O by in situ oxidation, were
2
2
found to be effective and reusable catalysts for dehydration of aldoximes, leading to a practical and scalable preparation of useful
organonitriles under mild conditions.
rganoselenium compounds have attracted much interest in
synthetic chemistry not only because they are important
H O (30% w/w) under air in the presence of (PhSe) . Contrary
2 2 2
O
to our expectations, the reaction gave no target phenylnitro-
methane 2a but varying yields of benzaldehyde 3a and
benzonitrile 4a instead (eq 1). Clearly, in addition to the usual
reagents and synthons in organic, pharmaceutical, and natural
1
product synthesis and materials science but also because many
of them exhibited significant biochemical and pharmaceutical
activities, such as antitumor, antibacterial, antiaging, and
2
antithyroid properties, most possibly due to the fact that
selenium is an ecofriendly element and a necessary trace element
3
metabolizable in organisms. Organoselenium compounds can
4
−13
also act as effective catalysts,
e.g., oxidation type reactions
4
5 6
such as epoxidation, dihydroxylation, halohydroxylations, and
7
8
haloamidations of alkenes, Baeyer−Villiger oxidation, oxida-
9
10
2
3
hydrolysis of 1a to 3a, an aldoxime dehydration reaction also
occurred to afford the unexpected nitrile 4a. More interestingly, a
higher yield of 4a was obtained when a lower amount of H O
tion and halogenation of sp and sp C−H bonds, allylic
1
1
12
amination, and oxidation of amines, as well as other types of
reactions such as Diels−Alder, Baylis−Hillman, and thioacetal-
2
2
1
was used (eq 1, entry 3). Since aldoxime dehydration to nitriles
was usually performed by using excess amounts of dehydrating
ization reactions, etc. In addition to developing novel methods
for the synthesis and applications of useful organoselenium
18
1
4
reagents or under transition-metal catalysis, this new finding
led us to investigate the reaction to develop a greener and more
practical method for organonitriles from the aldoximes.
compounds, we are also interested in organoselenium catalysis
and recently reported a Baeyer−Villiger oxidation of methyl-
enecyclobutanones and a dihydroxylation reaction of cyclo-
1
3
Based on our experience on organoselenium catalysis and to
minimize potential byproduct formation due to high catalyst
hexene. Herein we report the first organoselenium-catalyzed
dehydration reaction of aldoximes, which can be readily
conducted under mild conditions by using diaryl diselenides
13
loadings, catalytic activities of lower amounts of (PhSe) and
2
H O were then investigated. The reaction of 1 mol % of (PhSe)
(
ArSe) and H O as the effective and green precatalysts,
2
2
2
2
2
2
and 10 mol % of H O indeed gave a much lower yield of 3a and a
providing a practical and scalable method for synthesis of useful
2
2
1
5
slightly lower yield of 4a (Table 1, entry 1). A detailed screening
organonitriles.
Since organoselenium compounds are known to be good
19
on precatalyst loadings was then undertaken, showing that 4
mol % of both (PhSe) and H O could gave a rather good result
4
−13
oxidation catalysts,
we initially attempted the oxidation of
2
2
2
(
85% 4a, entry 2). In contrast, no reaction occurred in the
the readily available aldoximes intending to develop a new
absence of (PhSe) or H O (entries 3 and 4), showing that they
method for the synthesis of nitroalkanes because they are also a
2
2
2
16
class of useful compounds in chemistry and the known
methods still have limitations such as production of undesired
Received: January 9, 2014
Published: February 24, 2014
1
7
wastes. Thus, benzaldoxime 1a was first treated with aqueous
©
2014 American Chemical Society
1346
dx.doi.org/10.1021/ol500075h | Org. Lett. 2014, 16, 1346−1349

Organic Letters
Letter
a
Table 1. Catalyst and Condition Optimization
Table 2. Organoselenium-Catalyzed Aldoxime Dehydration
Reaction for Organonitrile Synthesis
a
b
b
entry
(PhSe) (mol %)
H O (mol %) 3a (%)
4a (%)
2
2
2
b
entry
1: R
4: yield (%)
1
2
3
4
5
6
7
8
9
(PhSe) (1)
10
4
0
4
4
4
4
4
4
4
4
4
4
4
16
7
0
0
9
7
8
7
7
6
8
7
9
8
25
2
1
2
3
4
5
6
7
8
9
1a: C H5
4a: 81
4b: 70
4c: 78
4d: 80
4e: 81
4f: 80
4g: 82
4h: 73
4i: 81
4j: 76
4k: 74
4l: 82
4m: 66
(PhSe) (4)
85 (74)
6
2
6
1b: 4-FC H4
(PhSe) (4)
0
2
(PhSe) (0)
0
6
1c: 2-ClC H4
2
(C H CH Se) (4)
50
6
1d: 3-ClC H4
6
5
2
2
(c-C H Se) (4)
82
6
1e: 4-ClC H4
6
11
2
(1-C H Se) (4)
34
6
1f: 4-BrC H4
10
7
2
1g: 4-CF C H
4
(4-MeOC H Se) (4)
65
3
6
6
4
2
(4-Me NC H Se) (4)
23
6
1h: 4-MeC H4
2
6
4
2
10
11
12
13
14
(3,5-(CF ) C H Se) (4)
29
6
1i: 3-MeC H4
3
2
6
3
2
10
11
12
13
6
1j: 4-MeOC H4
(3-ClC H Se) (4)
72
6
4
2
(2-FC H Se) (4)
58
6
1k: 4-t-BuC H4
6
4
2
10
1l: 1-C H7
(4-FC H Se) (4)
73
6
4
2
1m: 4-CH CHCH OC H
(3-FC H Se) (4)
91 (81)
2
2
6
4
6
4
2
c
a
14
15
1n: 2,4,6-Me
C
3
6
H
2
4n: <5
1
a (5 mmol), a diselenide, and H O (30% w/w aqueous solution)
2 2
b
d
d
1o: n-C H
4o: 85
4p: 76
4q: 71
4r: <5
4s: <5
4t: <5
6
13
17
were stirred in commercial MeCN (5 mL) under air. GC yields based
on 1a with biphenyl used as the internal standard. Isolated yields are
shown in parentheses.
1
6
1p: n-C H
8
17
1q: E-C
1r: i-Pr
H
6
CHCH
5
e
e
e
18
19
20
1s: c-C H
are both essential for the reaction and that a new organoselenium
species may be generated as the active catalyst of the reaction.
Screening on precatalyst loadings also showed that the (PhSe)2/
H O ratio is crucial for the reaction, for other ratios gave only
6
11
1t: t-Bu
a
1 (5 mmol), (3-FC H Se) /H O (0.2/0.2 mmol, 4/4 mol %) in
commercial MeCN (5 mL) was stirred under air and monitored by
TLC and/or GC. Isolated yields based on 1. 85% aldehyde 3n
recovered. 155 mmol scale. Nitriles purified by vacuum distillation.
6
4
2
2
2
2
2
1
9
b
c
low to moderate yields of 4a.
d
We next investigated a series of diselenides to identify the best
organoselenium precatalyst since different substitutents have
been known to affect the catalyst’s activity and reaction
efficiency. The readily available dialkyl diselenides with different
electronic properties to (PhSe) were first tested. Although
PhCH Se) gave an inferior result compared to (PhSe) (50%,
entry 5), the slightly more bulky (c-C H Se) gave a similar
result with (PhSe) (82%, entry 6). A more bulky (1-C H Se)
was then tested, but it gave a low yield of 4a (34%, entry 7). We
e
Also tested at 80 °C. Aldoximes were recovered.
8
the target nitriles (entries 2−13). In contrast, the more bulky
2,4,6-trimethylphenyl aldoxime 1n gave aldehyde 3n as the major
product, with only a trace of 4n detected (entry 14). In addition,
primary aliphatic and vinylic aldoximes could also be dehydrated
efficiently under the same conditions to give similarly good
results (entries 15−17), showing a relatively high tolerance of the
method. However, the reactions of secondary and tertiary
aliphatic aldoximes 1r−t were not successful even at a higher
temperature, giving only a trace amount of the nitriles with
recovery of the aldoximes (entries 18−20). The ineffective
reactions of 1n,r−t may be attributed to the bulky substituents
that hindered the interaction of the substrates and catalyst, in
analogy to the results of bulky catalysts (Table 1, entries 7, 10,
and 11). It is noteworthy that although the reactions of aliphatic
aldoximes were conducted on a much larger scale of 155 mmol
(Table 2, entries 15 and 16), they were still very efficient under
the standard conditions and afforded good yields of the nitriles by
2
(
2
2
2
6
11
2
2
10
7
2
next investigated electron-rich and -deficient (ArSe) with
2
different substituents such as 4-methoxy, 4-amino, trifluoro-
methyl, 3-chloro, and 2- or 4-fluoro groups (entries 8−13).
Unfortunately, these (ArSe) only gave low to moderate yields of
a (23−73%), all lower than that of (PhSe) . To our surprise, the
meta-fluoro analogue (3-FC H Se) was found to be the best
precatalyst, giving a high conversion of 1a and a good isolated
yield of 4a (81%, entry 14). The reason for the higher catalytic
activity of (3-FC H Se) was not clear but may be attributed to
fine-tuning of the electronic property of the phenyl ring by the
meta-F group. As shown in the table, (c-C H Se) and (4-
FC H Se) gave similar results to (PhSe) and (3-FC H Se) ,
whereas other diselenides, either with sterically more bulky
substituents or with substituents of strong electron-rich or
2
4
2
6
4
2
6
4
2
6
11
2
19
vacuum distillation, showing the scalability and practicality of
the present aldoxime dehydration method.
6
4
2
2
6
4
2
During the above studies, we also found that distillation of the
reaction mixtures not only afforded good yields of the target
aliphatic nitriles but also gave a deep yellow and sticky oily
residue containing the nonvolatile organoselenium catalyst
(Table 2, entries 15 and 16). Therefore, the possibility of
catalyst recycling and reuse were investigated by recharging the
freshly used flask containing the catalyst residue with a new
quantity of aldoximes. As shown in Figure 1, in 25 mmol scale
reactions of 1a, 1b, 1d, or 1o under the standard conditions, the
-
deficient properties, usually gave lower yields of 4a. The optimal
reaction (entry 14) was also tested under N to give a similar
result (83% 4a), revealing that air does not affect the reaction.
Thus, the conditions and operation of the reactions can be
simplified by being carried out under air.
2
1
9
(
3-FC H Se) and the optimized conditions were then
6 4 2
employed to extend the scope of the reaction (Table 2). Like
a (entry 1), electron-deficient and -rich aromatic aldoximes,
including those with slightly bulky ortho-substituents (entries 3,
2) and a terminal vinyl group (entry 13), reacted efficiently
under the standard conditions to give moderate to good yields of
1
20
organoselenium catalyst could be reactivated by H O and then
reused at least four to six times without obvious loss of its
catalytic activity, affording moderate to good yields of 4a, 4b, 4d,
2
2
1
1
347
dx.doi.org/10.1021/ol500075h | Org. Lett. 2014, 16, 1346−1349

Organic Letters
Letter
selenium (entries 5−7). Selenium as well as the in situ generated
PhSeOH, but not other elements or the acidity of the acids, are
clearly the key to facilitate an efficient aldoxime dehydration
reaction, further excluding the possibility of a Bronsted acid
catalyzed process. More interestingly, PhSeBr that can hydrolyze
to afford PhSeOH could also catalyze the reaction efficiently in
the presence of water (entry 8), whereas PhSeBr alone is not a
good precatalyst, giving only a low yield of 4a (entry 9). The
results also indicated that PhSeOH, generated by hydrolysis of
PhSeBr, rather than PhSeBr itself, should be a more active
catalyst for the reaction.
Figure 1. Organoselenium catalyst recovery and reuse in large scale
reactions under the standard conditions.
19
A possible mechanism of the present aldoxime dehydration
reaction is shown in Scheme 1. Thus, ArSeOH (5) may be
1
9
or 4o in each cycle. These results clearly revealed the
recyclability of the organoselenium catalyst and high practicality
of the method.
Scheme 1. Possible Mechanism for Organoselenium-
Catalyzed Aldoxime Dehydration Reaction
The active organoselenium catalyst and mechanism of this
interesting aldoxime dehydration reaction were our next
concern. Since equal amounts of (ArSe) and H O were
2
2
2
found to be the best precatalyst, we believe areneselenenic acids
(
ArSeOH, 5) that can be produced from diselenides via oxidation
2
1
by H O2 may be generated in situ as the active catalyst, but
2
ArSeOH are also notoriously unstable compounds difficult to be
2
2
obtained pure. To certify this hypothesis and originally to
develop more effective precatalysts, during catalyst screening we
also tested alkyl phenyl selenides because PhSeOH is the side
product of the well-known selenoxide syn-elimination reac-
2
2,23
tions.
As shown in Table 3, model reactions of 1a using i-
2
1
Table 3. Determination of the Active Organoselenium
Catalyst via Alternative Protocols
generated from (ArSe) via oxidation by H O , which is then
2
2
2
a
converted to the corresponding selenenic anhydride ArSeOSeAr
6). Then, 6 may react with aldoxime (1) to give a mixed
(
anhydride 7. We deduce 6 rather than 5 should be the more
active species in this step because it has been well-documented
that the unstable 5 can readily convert to 6 by self-condensation
and 6 can also react with various nucleophiles effectively to
b
b
entry
catalysts (mol %)
3a (%)
4a (%)
1
2
3
4
5
6
i-PrSePh (8), H O (8)
<3
<3
6
87
79
42
9
2
2
22
EtSePh (8), H O (8)
2
2
regenerate 5 and condensation products. In addition, the
moisture-sensitive and more active PhSeBr, which should be
more reactive than PhSeOH in condensation with 1, showed a
much lower catalytic activity than its hydrolysis product PhSeOH
(Table 3, entries 8 and 9). This result explains that 6 was quickly
formed as the more reactive organoselenium species. Upon
formation of 7, it may undergo a rearrangement to give its
selenoxide isomer 8 to facilitate a selenoxide syn-elimination
process to give product nitriles 4 and regenerate 5. The key role
of both PhSeOH and selenium observed in control reactions
(Table 3) also supports that an elimination reaction of
intermediate 8 analogous to the well-known selenoxide syn-
c-C H SePh (8), H O (8)
6
11
2
2
PhSePh (8), H O (8)
5
2
2
(PhS) (4), H O (4)
5
6
2
2
2
(PhTe) (4), H O (4)
7
10
0
2
2
2
c
7
other oxyacids (8)
<3
15
11
8
9
PhSeBr (8), H O (8)
81
38
2
PhSeBr (8)
a
1
a (5 mmol) and a catalyst were stirred in commercial MeCN (5
b
mL) under air. GC yields based on 1a with biphenyl used as the
c
internal standard. Oxyacids 4-CH C H SO H, AcOH, CF CO H,
H SO (50%), and CF SO H (15%) were tested.
3
6
4
3
3
2
2
4
3
3
2
2,23
PrSePh or EtSePh as the precatalysts indeed gave rather good
yields of 4a (entries 1 and 2), showing that PhSeOH, the
selenoxide syn-elimination byproduct of i-PrSePh and EtSePh, is
most possibly the active catalyst in the reaction. In contrast,
incomplete reaction of c-C H SePh gave a much lower yield of
a (entry 3). These results showed a rate order of i-PrSePh >
EtSePh > c-C H SePh in dehydration of 1a, which in
comparison is in good agreement with the rate order of
selenoxide syn-elimination reactions of i-PrSePh > EtSePh > c-
C H SePh (also the rate order of PhSeOH formation) as
documented in the literature, further supporting that ArSeOH
is indeed the active catalyst of the reaction. On the contrary,
negative results were observed in the reactions of PhSePh, which
is incapable of undergoing selenoxide syn-elimination (entry 4),
elimination
most likely took place in the reaction. Although
this mechanism remains to be fully clarified and alternative
processes may also exist, Scheme 1 should be the most likely
mechanism based on the above experimental findings and the
21−23
6
11
related literatures.
4
In conclusion, we have developed a mild and simple aldoxime
dehydration reaction by using recyclable organoselenium
catalysts generated in situ from the readily available (ArSe)2
and the green oxidant H O , which provided a practical and
6
11
2
2
6
11
23a
scalable new method for synthesis of the useful organonitriles
form the readily available aldoximes. To our knowledge, this may
be the first example of an organoselenium-catalyzed dehydration
reaction. Deeper mechanistic studies and further extension of the
present dehydration method are underway.
(
PhS) , (PhTe) , and other usual oxyacids containing no
2 2
1
348
dx.doi.org/10.1021/ol500075h | Org. Lett. 2014, 16, 1346−1349

Organic Letters
Letter
2
006, 71, 5811. (b) Mellegaard-Waetzig, S. R.; Wang, C.; Tunge, J. A.
ASSOCIATED CONTENT
Supporting Information
■
Tetrahedron 2006, 62, 7191. (c) Drake, M. D.; Bateman, M. A.; Detty,
M. R. Organometallics 2003, 22, 4158.
*
S
Experimental details, condition screening table, product
(11) Trenner, J.; Depken, C.; Weber, T.; Breder, A. Angew. Chem., Int.
Ed. 2013, 52, 8952.
1
13
characterization, and H and C NMR spectra of the products.
This material is available free of charge via the Internet at http://
pubs.acs.org.
(
2
12) (a) Gebhardt, C.; Priewisch, B.; Irran, E.; Ru
008, 1889. (b) Zhao, D.; Johansson, M.; Backvall, J.-E. Eur. J. Org.
Chem. 2007, 4431.
13) (a) Yu, L.; Wu, Y.; Cao, H.; Zhang, X.; Shi, X.; Luan, J.; Chen, T.;
̈
ck-Braun, K. Synthesis
̈
(
AUTHOR INFORMATION
Corresponding Authors
■
Pan, Y.; Xu, Q. Green Chem. 2014, 16, 287. (b) Yu, L.; Wang, J.; Chen,
T.; Ding, K.-H.; Pan, Y. Chin. J. Org. Chem. 2013, 13, 1096.
(14) (a) Yu, L.; Wu, Y.-L.; Chen, T.; Pan, Y.; Xu, Q. Org. Lett. 2013, 15,
*
E-mail: yulei@yzu.edu.cn.
1
44. (b) Yu, L.; Ren, L.-F.; Yi, R.; Wu, Y.-L.; Chen, T.; Guo, R. J.
*E-mail: qing-xu@wzu.edu.cn.
Organomet. Chem. 2011, 696, 2228. (c) Yu, L.; Meng, J.-D.; Xia, L.; Guo,
R. J. Org. Chem. 2009, 74, 5087. (d) Meng, B.; Yu, L.; Huang, X.
Tetrahedron Lett. 2009, 50, 1947. (e) Yu, L.; Meng, B.; Huang, X. Synlett
Notes
The authors declare no competing financial interest.
2
007, 2919. (f) Yu, L.; Huang, X. Synlett 2007, 1371. (g) Yu, L.; Chen,
B.; Huang, X. Tetrahedron Lett. 2007, 48, 925. (h) Yu, L.; Huang, X.
Synlett 2006, 2136.
(15) (a) Kim, J.; Kim, H. J.; Chang, S. Angew. Chem., Int. Ed. 2012, 51,
ACKNOWLEDGMENTS
This work was supported by NNSFC (21202141, 20902070)
and the 580 Oversea Talents Program of Wenzhou City.
■
11948. (b) Guer
9. (c) Martin, A.; Kalevaru, V. N. ChemCatChem 2010, 2, 1504.
d) Velankar, H.; Clarke, K. G.; du Preez, R.; Cowan, D. A.; Burton, S. G.
́
inot, A.; Reymond, S.; Cossy, J. Eur. J. Org. Chem. 2012,
1
(
REFERENCES
■
Trends Biotechnol. 2010, 28, 561. (e) Frizler, M.; Stirnberg, M.; Sisay, M.
T.; Gutschow, M. Curr. Top. Med. Chem. 2010, 10, 294. (f) Rach, S. F.;
Kuhn, F. E. Chem. Rev. 2009, 109, 2061. (g) Kukushkin, V. Y.; Pombeiro,
A. J. L. Chem. Rev. 2002, 102, 1771.
(
1) (a) Wirth, T. Organoselenium Chemistry; Springer: Berlin, 2000;
Vol. 208. (b) Ogawa, A. In Main Group Metals in Organic Synthesis;
Yamamoto, H., Oshima, K., Eds.; Wiley-VCH: Weinheim, 2004; Vol. 2,
̃
p 813. (c) Perin, G.; Lenardao, E. J.; Jacob, R. G.; Panatieri, R. B. Chem.
Rev. 2009, 109, 1277. (d) Freudendahl, D. M.; Santoro, S.; Shahzad, S.
A.; Santi, C.; Wirth, T. Angew. Chem., Int. Ed. 2009, 48, 8409. (e) Wirth,
T. Organoselenium Chemistry: Synthesis and Reactions; Wiley-VCH:
Weinheim, 2011. (f) Beletskaya, I. P.; Ananikov, V. P. Chem. Rev. 2011,
11, 1596. (g) Godoi, B.; Schumacher, R. F.; Zeni, G. Chem. Rev. 2011,
11, 2937. (h) Nomoto, A.; Higuchi, Y.; Kobiki, Y.; Ogawa, A. Mini-Rev.
(16) (a) Noble, A.; Anderson, J. C. Chem. Rev. 2013, 113, 2887.
(b) Ballini, R.; Barboni, L.; Fringuelli, F.; Palmieri, A.; Pizzo, F.; Vaccaro,
L. Green Chem. 2007, 9, 823. (c) Ono, N. The Nitro Group in Organic
Synthesis; Wiley: New York, 2001. (d) Rosini, G. The Henry
(
Nitroaldol) Reaction. In Comprehensive Organic Synthesis; Trost, B.
M., Fleming, I., Eds.; Pergamon: Oxford, 1991; Vol. 2, pp 321−340.
e) Rosini, G.; Ballini, R. Synthesis 1986, 833. (f) Baer, H. H.; Urbas, L.
1
1
(
Med. Chem. 2013, 13, 814. (i) Li, Q.-S.; Wu, D.-M.; Zhu, B.-C.; Wang,
Y.-G. Mini-Rev. Med. Chem. 2013, 13, 854.
2) (a) Yang, J.-Y.; Xu, C.-S. Pharmacol. Rep. 2009, 61, 288. (b) Roy,
The Chemistry of the Nitro and Nitroso Groups; Feuer, H., Ed.; Wiley
Interscience: New York, 1970; Vol. 2.
(
(
17) (a) Emmons, W. D.; Pagano, A. S. J. Am. Chem. Soc. 1955, 77,
557. (b) Ballistreri, F. P.; Barbuzzi, E.; Tomaselli, G. A.; Toscano, R. M.
Synlett 1996, 1093. (c) Cardona, F.; Soldaini, G.; Goti, A. Synlett 2004,
553.
18) Selected examples: (a) Hart-Davis, J.; Battioni, P.; Boucher, J.-L.;
G.; Mugesh, G. Chem. Biodivers. 2008, 5, 414. (c) Sanmartin, C.; Plano,
D.; Palop, J. A. Mini-Rev. Med. Chem. 2008, 8, 1020. (d) Nogueira, C. W.;
Zeni, G.; Rocha, J. B. T. Chem. Rev. 2004, 104, 6255. (e) Chasteen, T. G.;
Bentley, R. Chem. Rev. 2003, 103, 1. (f) Gromer, S.; Gross, J. H. J. Biol.
Chem. 2002, 277, 9701. (g) Birringer, M.; Pilawa, S.; Flohe, L. Nat. Prod.
Rep. 2002, 19, 693.
3) (a) Rayman, M. P. Lancet 2012, 379, 1256. (b) Mehdi, Y.; Hornick,
J.-L.; Istasse, L.; Dufrasne, I. Molecules 2013, 18, 3292.
4) (a) ten Brink, G.-J.; Fernandes, B. C. M.; van Vliet, M. C. A.;
Arends, I. W. C. E.; Sheldon, R. A. J. Chem. Soc., Perkin Trans. 1 2001,
24. (b) Betzemeier, B.; Lhermitte, F.; Knochel, P. Synlett 1999, 489.
5) (a) Santi, C.; Lorenzo, R. D.; Tidei, C.; Bagnoli, L.; Wirth, T.
Tetrahedron 2012, 68, 10530. (b) Santoro, S.; Santi, C.; Sabatini, M.;
Testaferri, L.; Tiecco, M. Adv. Synth. Catal. 2008, 350, 2881.
6) (a) Carrera, I.; Brovetto, M. C.; Seoane, G. A. Tetrahedron Lett.
006, 47, 7849. (b) Mellegaard, S. R.; Tunge, J. A. J. Org. Chem. 2004,
9, 8979.
7) (a) Chen, F.; Tan, C. K.; Yeung, Y.-Y. J. Am. Chem. Soc. 2013, 135,
232. (b) Tay, D. W.; Tsoi, I. T.; Er, J. C.; Leung, G. Y. C.; Yeung, Y.-Y.
Org. Lett. 2013, 15, 1310.
8) (a) Ichikawa, H.; Usami, Y.; Arimoto, M. Tetrahedron Lett. 2005,
6, 8665. (b) ten Brink, G.-J.; Vis, J. M.; Arends, I. W. C. E.; Sheldon, R.
A. Tetrahedron 2002, 58, 3977. (c) ten Brink, G.-J.; Vis, J.-M.; Arends, I.
W. C. E.; Sheldon, R. A. J. Org. Chem. 2001, 66, 2429. (d) Syper, L.
Synthesis 1989, 167.
9) (a) Singh, F. V.; Wirth, T. Org. Lett. 2011, 13, 6504. (b) Bennett, S.
M.; Tang, Y.; McMaster, D.; Bright, F. V.; Detty, M. R. J. Org. Chem.
008, 73, 6849. (c) Niyomura, O.; Cox, M.; Wirth, T. Synlett 2006, 251.
d) Goodman, M. A.; Detty, M. R. Organometallics 2004, 23, 3016.
e) Tiecco, M.; Testaferri, L.; Tingoli, M.; Bartoli, D. J. Org. Chem. 1990,
4
1
(
Mansuy, D. J. Am. Chem. Soc. 1998, 120, 12524. (b) Yang, S. H.; Chang,
S. Org. Lett. 2001, 3, 4209. (c) Ishihara, K.; Furuya, Y.; Yamamoto, H.
Angew. Chem., Int. Ed. 2002, 41, 2983. (d) De Luca, L.; Giacomelli, G.;
Porcheddu, A. J. Org. Chem. 2002, 67, 6272. (e) Yamaguchi, K.;
Fujiwara, H.; Ogasawara, Y.; Kotani, M.; Mizuno, N. Angew. Chem., Int.
Ed. 2007, 46, 3922. (f) Rai, A.; Yadav, L. D. S. Eur. J. Org. Chem. 2013,
(
(
2
(
1
(
(
889. (g) Tambara, K.; Pantos,
19) See the Supporting Information for details.
20) Most possibly because reduced organoselenium species were
̧ G. D. Org. Biomol. Chem. 2013, 11, 2466.
generated (see ref 13b for similar findings), reactivation of the catalyst by
(
2
6
(
19
adding 4 mol % of H O was necessary in each cycle.
2
2
(21) (a) Hori, T.; Sharpless, K. B. J. Org. Chem. 1978, 43, 1689.
(b) Reich, H. J.; Wollowitz, S.; Trend, J. E.; Chow, F.; Wendelborn, D. F.
J. Org. Chem. 1978, 43, 1697. (c) Mugesh, G.; Panda, A.; Singh, H. B.;
Punekar, N. S.; Butcher, R. J. J. Am. Chem. Soc. 2001, 123, 839.
1
(22) (a) Kang, S.-I.; Kice, J. L. J. Org. Chem. 1985, 50, 2968. (b) Kice, J.
(
4
L.; McAfee, F.; Slebocka-Tilk, H. J. Org. Chem. 1984, 49, 3100. (c) Kice,
J. L.; McAfee, F.; Slebocka-Tdk, H. Tetrahedron Lett. 1982, 23, 3323.
(
2
d) Reich, H. J.; Willis, W. W., Jr.; Wollowitz, S. Tetrahedron Lett. 1982,
3, 3319.
23) For reviews: (a) Reich, H. J. Acc. Chem. Res. 1979, 12, 22.
b) Liotta, D. Acc. Chem. Res. 1984, 17, 28. For reports, see: (c) Zhou, Z.
(
(
(
S.; Jiang, N.; Hilvert, D. J. Am. Chem. Soc. 1997, 119, 3623. (d) Reich, H.
J.; Hoeger, C. A.; Willis, W. W., Jr. J. Am. Chem. Soc. 1982, 104, 2936.
2
(
(
5
(
(
e) Reich, H. J.; Willis, W. W., Jr. J. Am. Chem. Soc. 1980, 104, 5967.
f) Reich, H. J.; Reich, L. L.; Wollowitz, S. J. Am. Chem. Soc. 1978, 100,
5, 4523.
10) (a) Barrero, A. F.; del Moral, J. F. Q.; Herrador, M. M.; Cortes
Arteaga, P.; Catalan, J. V.; Sanchez, E. M.; Arteaga, J. F. J. Org. Chem.
5
981. (g) Sharpless, K. B.; Young, M. W. J. Org. Chem. 1975, 40, 947.
(
́
, M.;
́
́
1
349
dx.doi.org/10.1021/ol500075h | Org. Lett. 2014, 16, 1346−1349