Visible-Light-Promoted Metal-Free Aerobic Hydroxyazidation of Alkenes

Article abstract of DOI:10.1021/acscatal.7b02892

A highly efficient visible-light-promoted metal-free aerobic hydroxyazidation of alkenes has been developed. This protocol was operationally simple with broad substrate scope using relatively simple and readily available starting materials, such as alkene

Full text of DOI:10.1021/acscatal.7b02892

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Article
Visible Light Promoted Metal-Free Aerobic Hydroxyazidation of Alkenes
Bo Yang, and Zhan Lu
ACS Catal., Just Accepted Manuscript • DOI: 10.1021/acscatal.7b02892 • Publication Date (Web): 30 Oct 2017
Downloaded from http://pubs.acs.org on October 30, 2017
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ACS Catalysis
Visible Light Promoted Metal-Free Aerobic Hydroxyazidation
of Alkenes
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Bo Yang, Zhan Lu*
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Department of Chemistry, Zhejiang University, Hangzhou 310058, China
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Supporting Information Placeholder
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ABSTRACT: A highly efficient visible light promoted metalꢀ
free aerobic hydroxyazidation of alkenes has been developed.
This protocol was operationally simple with broad substrate scope
using relatively simple and readily available starting materials,
such as alkenes and air, to construct valuable ßꢀazido alcohols
which are significant building blocks to build Nꢀcontaining comꢀ
pounds. The distinct possible mechanisms were proposed via the
generation of azido radical and alkene radical cation.
KEYWORDS: metal-free, hydroxyazidation, alkenes, visible
light
The direct and regioselective olefin difunctionalization is one of
the most efficient strategies for the synthesis of 1,2ꢀ
difunctionalized products1 which have been widely used for conꢀ
structing complex natural products or diversified chemical librarꢀ
ies. The ßꢀazido alcohols are a significant class of compounds in
synthetic chemistry, which have emerged tremendous utilities in
chemistry, medicine, biology as well as materials science.2 The ßꢀ
azido alcohols exist in biologically active molecules,3 and also
serve as synthetic precursors of ßꢀamino alcohols4 and Nꢀ
containing heterocycles.5 Conventionally, the ßꢀazido alcohols are
prepared through the ring opening of corresponding epoxides or
substitution of ßꢀhaloalcohols.6 However, these methods suffer
from the prefunctionalization of the corresponding starting mateꢀ
rials and limited the substrate scope. The direct olefin difunctionꢀ
alization offers a great chance for the construction of ßꢀazido
alcohols from readily available starting materials.
Shibasaki and coꢀworkers7 developed a directly (Cl2SnO)nꢀ
catalyzed hydroxyazidation of alkenes to provide ßꢀazido alcohols
in moderate yields using the superstoichiometric peroxy reagent.
Despite several achievements (Scheme 1a)8 have been made by
these methods, there are still some issues to be addressed: 1) stoiꢀ
chiometric or excess oxidants, such as high valent iodine salts or
peroxy reagent, are used; 2) the tolerance of functional group is
not so well; 3) the specified Oꢀsources, such as hydroxylamine or
TEMPO limit their further utilities. Recently, Jiao9 developed a
facile Mnꢀcatalyzed highly efficient aerobic hydroxyazidation of
alkenes using TMSN3 as N3 source and dioxygen as oxygen
source (Scheme 1b). The azido radical was proposed as an initial
activated intermediate. Although it is a great stride in this field,
the development of highly efficient and metalꢀfree aerobic methꢀ
ods is still remain a challenge and highly desirable. Visible light,
as a safe, abundant and clean energy source, has emerged as a
powerful tool to construct organic molecules under mild condiꢀ
tions.10 Dioxygen is generally considered as an ideal and green
oxidant, and also a clean and cheap oxygen source.11
Scheme 1. Catalytic oxyazidation of alkenes.
diastereoselectivity.12 We consequently aimed at extending more
general, efficient and powerful methodology to furnish valuable
amino alcohol derivatives. Herein, we report a visible light proꢀ
moted metalꢀfree aerobic hydroxyazidation of alkenes. The olefin
radical cation or azido radical were proposed (Scheme 1c).
In an initial investigation to optimize the reaction, we employed
αꢀmethyl styrene 1a as a model substrate, TMSN3 as a nitrogen
source, dioxygen gas as an oxygen source, 4Å MS as a desiccant
ꢀ
and Acr+MesClO4 (9ꢀmesitylꢀ10ꢀmethylacridinium perchlorate)
as a visible light photocatalyst at room temperature under the
irradiation of 8W blue LEDs (Table 1). To our delight, the reacꢀ
tion in a solution of acetonitrile afforded the ((1ꢀazidoꢀ2ꢀ
phenylpropanꢀ2ꢀyl)peroxy)trimethylsilane 3a in 41% yield (entry
1). Various solvents, such as dichloromethane, tetrahydrofuran
and toluene were used instead of acetonitrile. Toluene was more
suitable for this transformation, yielding 3a in 87% yield (entry
4). When the catalyst loading was reduced to 3 mol%, the reaction
afforded 3a in 95% yield (entry 5). Further reducing the catalyst
loading, the yields were decreased (entries 6 and 7). The reaction
could be completed in 4 h (entry 8). The ruthenium or iridium
photocatalysts did not work for this transformation (entries 9 and
10). Control experiments were performed either without photoꢀ
catalyst or light (entries 11 and 12), reactions did not occur at all.
The amount of TMSN3 could be reduced to 2 equiv., however,
using 3 equiv. of TMSN3 afforded 3a in a better yield (entries 13
and 14). Air could be used instead of O2 balloon (entry 15). The
reaction without 4Å MS underwent smoothly to afford 5a in 94%
yield after reduction of 3a (entry 16). When heated at 80 oC in the
absence of light, the model reaction did not work.
To the best of our knowledge, visible light promoted hydroxyꢀ
amination of alkenes using molecular oxygen as an oxygen source
has not been previously reported. Prior to this work, we have deꢀ
veloped a visible lightꢀpromoted neutral intramolecular oxyamiꢀ
nation of alkenes with highly controllable
With the optimal reaction conditions in hand, we next investiꢀ
gated the scope of a variety of 1,1ꢀdisubstituted alkenes summaꢀ
rized in Table 2. The methyl group on ortho-, metaꢀ and paraꢀ
positions on styrene could be tolerated (5b-d). A number of
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Table 2. Substrate scopea
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Table 1. Optimization of the reaction conditions.
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Entry TMSN3(equiv.) PC (mol%)
Solvent
MeCN
DCM
Yield (%)a
1
TMSN3 (5)
TMSN3 (5)
TMSN3 (5)
TMSN3 (5)
TMSN3 (5)
TMSN3 (5)
TMSN3 (5)
TMSN3 (5)
TMSN3 (5)
TMSN3 (5)
TMSN3 (5)
TMSN3 (5)
TMSN3 (3)
TMSN3 (2)
TMSN3 (3)
Acr+MesClO4ꢀ (5)
Acr+MesClO4ꢀ (5)
Acr+MesClO4ꢀ (5)
Acr+MesClO4ꢀ (5)
Acr+MesClO4ꢀ (3)
Acr+MesClO4ꢀ (2)
Acr+MesClO4ꢀ (1)
Acr+MesClO4ꢀ (3)
Ru(bpy)3(PF6)2 (3)
41
40
43b
87
95
86
20
97
0
2
10
11
12
13
14
15
16
17
18
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21
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3
THF
4
Toluene
Toluene
Toluene
Toluene
Toluene
Toluene
5
6
7
8c
9c
10c
11c
12c,d
13c
14c
15c,e
Ir(ppy)2(dtbbpy)PF6(3) Toluene
0
ꢀ
Toluene
Toluene
Toluene
Toluene
Toluene
Toluene
Toluene
0
Acr+MesClO4ꢀ (3)
Acr+MesClO4ꢀ (3)
Acr+MesClO4ꢀ (3)
Acr+MesClO4ꢀ (3)
Acr+MesClO4ꢀ (3)
Acr+MesClO4ꢀ (3)
0
90
86
95
94g
0
16c,e,f TMSN3 (3)
17d,h
TMSN3 (3)
a1a (0.3 mmol). Yields of 3a were determined by H NMR with mesityꢀ
1
lene as an internal standard. b39% yield of 4a was observed. cThe reaction
d
e
f
was run for 4 h. Without light. Air was used instead of O2 balloon. No
4Ǻ MS. gThe crude product was stirred in MeCN (2 mL) with PPh3
(1equiv.) and HCl (Conc.) (2 equiv.) at r.t. for 30 min to obtain the final
product. The isolated yield of 5a. h80 oC
styrenes bearing both the electronꢀdonating and electronꢀ
withdrawing groups, such as ether, halides, trifluoromethyl, pheꢀ
nol, aldehyde, acid, ester, amide, free amine and alcohols could be
converted to the corresponding desired ßꢀazido alcohols in good
to excellent yields (5e-n). The αꢀsubstituents on styrenes could be
not only 1oꢀalkyl group but also more sterically hindered 2oꢀ and
3oꢀalkyl groups (5o-t). The 1ꢀnaphthyl and 2ꢀpyridyl substrates
could be transformed into the ßꢀazido alcohols 5u-v in 54 and
92% yield, respectively. Notably, the 1ꢀmethyleneindane and 5ꢀ
methyleneꢀ6,7,8,9ꢀtetrahydroꢀ5Hꢀbenzo[7]annulene could be
delivered into 3w and 5x in good yields, respectively. The 1,1ꢀ
diaryl terminal alkenes were allowed for the transformations
providing 5y and 5z with up to 99% yields. It is noteworthy that
the reaction of 1,1ꢀdiphenylethylene could be conducted in a
gramꢀscale under air to afford the 5y in 93% yield. Importantly,
the reactions of 1,1ꢀdialkyl terminal alkenes proceeded smoothly
to provide the ßꢀazido alcohols 5aa-ab in good yields. It was worꢀ
thy to note that the allylic alcohol was also feasible for this transꢀ
formation to access 5ac in 55% yield. Further interrogation of the
substrate scopes of this transformation was illustrated. Due to
potential over oxidation of products, the reactions of the monoꢀ
substituted styrenes afforded the corresponding hydroxyazidation
products 6a-i with a slightly low yield (46ꢀ76%). Moreover, easily
oxidized Sꢀcontaining substrates such as thiol ether and thiophene
were tolerated to be convert to the desired products 6j-k in modꢀ
erate yields. The 1,2ꢀdisubstituted internal alkenes were also suitꢀ
able partners with TMSN3 to deliver the corresponding products
6l-m. Gratifyingly, the cyclic alkenes, such as indene and cycloꢀ
hexene, could be reacted smoothly under the standard conditions
to access the desired products in 61% yield with 3/1 dr and 55%
yield with 2/1 dr, respectively. The ßꢀmethyl styrene could also be
transformed into the product 6n in 87% yield with 2/1 dr. To our
ꢀ
aStandard conditions: alkenes (0.3 mmol), Acr+MesClO4 (0.03 equiv.),
TMSN3 (3 equiv.) in a solution of toluene (0.05 M) under the irradiation
of 8 W blue LEDS under air for 4 h at room temperature. Isolated yield of
products after treated with HCl (Conc.) (2 equiv.) and PPh3 (1.0 equiv.) in
MeCN (2 mL). b6 h. c12 h. d3/1 dr. e2/1 dr.
delight, the trisubstituted and fully substituted alkenes bearing
relatively bulkier hindrance could also participate to deliver 6o
and 6p in 98% and 69% yields, respectively. To explore its utility
for lateꢀstage functionalization of complex molecules, estroneꢀ
derived styrene was converted to hydroxyazidation product 6q in
70% yield. This result shows great potential for the structure modꢀ
ification of an array of complex biological molecules in medicinal
chemistry.13
There are great utilities for ßꢀazido alcohols which could be
transformed to a variety of useful molecules (Scheme 2).14 Oxazoꢀ
line 7, ßꢀazide ketone 8 and ßꢀazide ester 9 could be obtained via
the cyclization with benzaldehyde or oxidation or esterification
reactions of 6a, respectively. The ßꢀazido alcohol 6a could be
easily transformed to antiꢀmalarial product 15 in 57% yields over
two steps and phenylephrine 16, a approved drug.14f Additionally,
triazole 12 and lactam 13 could be obtained through "click" reacꢀ
tion with phenylacetylene or Schmidt reaction. Amino alcohol 14
was also obtained through hydrogenation.
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Scheme 4. A Plausible Mechanism.
to from 22. During the investigation of substrate scope, the longer
time of reaction of the αꢀmethyl styrene bearing electronꢀ
withdrawing groups with TMSN3 was needed and the yields of
reaction of monosubstituted styrenes were relative lower
compared to the reaction of the αꢀmethyl styrene. These results
suggested that the reactions were provided with the choice of two
alternative pathways, alkene oxidation pathway and azido radical
pathway.
Scheme 2. Transformations of ß-azido alcohols and syn-
thesis of bioactive compounds.
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To gain mechanistic insights, control experiments were
performed in Scheme 3. In the presence of radical trap TEMPO,
the reaction almost shut down (eq. 1), indicating that a radical
intermediate might be involved in this transformation. The radical
clock reaction of vinylcyclopropane 15 was performed to afford
the radical ringꢀopening product 16 in 84% yield, suggesting that
this protocol undergoes via a radical pathway (eq. 2).
In summary, we have developed a highly efficient metalꢀfree
visible light promoted hydroxyazidation of alkenes using air as
the terminal oxidant to afford ßꢀazido alcohols. This protocol
features metalꢀfree and mild conditions with excellent functionalꢀ
group toleration and air serving as both the oxygen source and
electron acceptor. The resulting ßꢀazido alcohols can be used as
direct precursors to construct an array of important molecules.
The alternative possible mechanisms were proposed via the
generation of azido radical or alkene radical cation. Current
efforts in our laboratory are underway to explore asymmetric
transformations.
ASSOCIATED CONTENT
AUTHOR INFORMATION
Scheme 3. Mechanistic studies
Based on the previously reported literature result,15 the alkene
could be directly oxidized to be the radical cation by excited state
of 9ꢀmesitylꢀ10ꢀmethylacridinium perchlorate.
Corresponding Author
*Eꢀmail: luzhan@zju.edu.cn
The plausible mechanisms for this transformation are proposed
in Scheme 4. The photosensitizer (MesꢀAcr+) absorbs visible light
under the irradiation of 8 w blue LEDs to generate its excited state
(Ered* = 2.06 V vs SCE)16 which could oxidize the styrene 1a
(Eox = 1.91 V vs SCE)17 to afford corresponding radical cation 18
and the reduced species III (MesꢀAcr•). The MesꢀAcr• could be
oxidized by dioxygen to provide superoxide 17 and regenerate
photocatalyts. The high regioselective reaction of radical cation
18 is attributed to the fact that the charge of the resonance hybrid
is usually found at the less substituted position.18 Moreover,
Arnold19 found that the radical with more substituents resulting
from nucleophilic attack on the alkene radical cation was more
favored on the basis of computational studies. The radical cation
18 is then captured by TMSN3 to afford the benzylic radical 21.
The benzylic radical 21 is consequently reacted with superoxide
17 and TMS+ to afford the peroxyazidation product 22,
exclusively. Alternatively, it should be noted that the oxidation
potential of free azide anion is found to be +1.32 V (NHE).20 The
fact that the oxidation potential of the azide anion is quite a bit
lower than that of alkene demonstrates the possibility that the
excited state II could oxidize azide anion to the azido radical 20
following trapping by alkenes to form 21. Importantly, III could
also react directly with peroxy radicals 23 resulting from the
trapping of oxygen by 21 to generate 24 which react with TMS+
Notes
The authors declare no competing financial interests.
Supporting Information
The Supporting Information is available free of charge on the
ACS Publications website. Experimental procedures, characterizaꢀ
tion data for all compounds (PDF).
ACKNOWLEDGMENT
Financial support was provided by the National 973 Program
(2015CB856600), NSFC (21472162).
REFERENCES
（1）For selected reviews on difunctionalizations of alkenes, see: a)
Muniz, K. Chem. Soc. Rev. 2004, 33, 166. b) Minatti, A.; Muniz, K.
Chem. Soc. Rev. 2007, 36, 1142. c) McDonald, R. I.; Liu, G.; Stahl, S.
S. Chem. Rev. 2011, 111, 2981. d) Cao, M.ꢀY.; Ren, X.; Lu, Z. Tetra-
hedron Lett. 2015, 56, 3732. e) Zhang, B.; Studer, A. Org. Lett. 2013,
15, 4548. f) Fu, N.; Sauer, G. S.; Saha, A.; Loo, A.; Lin, S. Science
2017, 357, 575. g) Zhang, B.; Studer, A. Org. Lett. 2013, 15, 4548.
（2）Sletten, E. M.; Bertozzi, C. R. Acc. Chem. Res. 2011, 44, 666. b)
Huryn, D. M.; Okabe, M. Chem. Rev. 1992, 92, 1745. c) Meldal, M.;
ACS Paragon Plus Environment

ACS Catalysis
Page 4 of 5
Tornoe, C. W. Chem. Rev. 2008, 108, 2952. d) Wu, K.; Liang, Y.; Jiao,
Jiao, N. Chem. Soc. Rev. 2012, 41, 3381. c) Cheng, X.; Hu, X.; Lu, Z.
N.; Molecules 2016, 21, 352.
Chin. J. Org. Chem. 2017, 37, 251.
（12）Ren, X.; Guo, Q.ꢀH.; Chen, J.ꢀH.; Xie, H.ꢀJ.; Xu, Q.; Lu, Z.
Chem. Eur. J. 2016, 22, 18695.
（13）Karimov, R. R.; Sharma, A.; Hartwig, J. F. ACS Cent. Sci.
2016, 2, 715.
1
2
3
4
5
6
7
8
（3）Badiang, J. G.; Aube, J. J. Org. Chem. 1996, 61, 2484. b) Hang,
K.; Wang, H.; Stepanenko, V.; De Jesus, M.; Torruellas, C.; Correa, W.;
OrtizꢀMarciales, M. J. Org. Chem. 2011, 76, 1883. c) Scriven, E. F. V.;
Turnbull, K. Chem. Rev. 1988, 88, 297. d) Smith, B. T.; Gracias, V.;
Aube, J. J. Org. Chem, 2000, 65, 3771. e) Sabitha, G.; Babu, R. S.;
Rajkumar, M.;Yadav, J. S. Org. Lett, 2002, 4, 343.
（4）Bergmeier, S. C. Tetrahedron. 2000, 56, 2561. b) Ager, D. J.;
Prakash, I.; Schaad, D. R. Chem. Rev. 1996, 96, 835.
（5）Tanner, D. Angew. Chem. Int. Ed. 1994, 33, 599. b) Sweeney, J.
B. Chem. Soc. Rev. 2002, 31, 247.
（6）a) Larrow, J. F.; Schaus, S. E.; Jacobsen, E. N. J. Am. Chem.
Soc. 1996, 118, 7420. b) Lohray, B. B.; Ahuja, J. R. J. Chem. Soc,
Chem. Commun. 1991, 95. c) Spelberg, J. H. L.; van HylckamaVlieg,
J. E. T.; Tang, L.; Janssen, D. B.; Kellog, R. M. Org. Lett. 2001, 3, 41.
（7）Sakurada, I.; Yamasaki, S.; Kanai, M.; Shibasaki, M. Tetrahe-
dron Lett. 2000, 41, 2415.
（8）a) Prasad, P. K.; Reddi, R. N.; Sudalai, A. Chem. Commun.
2015, 51, 10276. b) Fumagalli, G.; Rabet, P. T. G.; Boyd, S.; Greaney,
M. F. Angew. Chem. Int. Ed. 2015, 54, 11481. c) Zhang, B.; Studer, A.
Org. Lett. 2013, 15, 4548. d) Xia, X.ꢀF.; Gu, Z.; Liu, W.; Wang, H.;
Xia, Y.; Gao, H.; Liu, X.; Liang, Y.ꢀM. J. Org. Chem. 2015, 80,290. e)
Sequeira, F. C.; Chemler, S. R. Org. Lett. 2012, 14, 4482. f) Zhu, R.;
Buchwald, S. L. J. Am. Chem. Soc. 2015, 137, 8069. g) Zhu, L.; Yu,
H.; Xu, Z.; Jiang, X.; Lin, L.; Wang, R. Org. Lett. 2014, 16, 1562.
（9）Sun, X.; Li, X.; Song, S.; Zhu, Y.; Liang, Y.ꢀF.; Jiao, N. J. Am.
Chem. Soc. 2015, 137, 6059.
（10）For selected reviews on visible light photocatalysis in organic
transformations, see: a) Yoon, T. P.; Ischay, M. A.; Du, J. Nat. Chem.
2010, 2, 527. b) Narayanam, J. M.; Stephenson, C. R. J. Chem. Soc.
Rev. 2011, 40, 102. c) Teplý, F. Collect. Czech. Chem. Commun. 2011,
76, 859. d) Xuan, J.; Xiao, W.ꢀJ. Angew. Chem. Int. Ed. 2012, 51, 6828.
e) Prier, C. K.; Rankic, D. A.; MacMillan, D. W. C. Chem. Rev. 2013,
113, 5322. f) Cismesia, M. A.; Yoon, T. P. Chem. Sci. 2015, 6, 5426.
（11）For selected reviews on dioxygen serving as oxidants, see: a)
Stahl, S. S. Science 2005, 309, 1824. b) Shi, Z.; Zhang, C.; Tang, C.;
（14）a) Wang, Y.; Chen, H.; Zhu, X.; Chiba, S. J. Am. Chem. Soc.
2012, 134, 11980. b) Kim, Y.; Pak, H. K.; Rhee, Y. H.; Park, J. Chem.
Commun. 2016, 52, 6549. c) Cho, B. T.; Kang, S. K.; Shin, S. H. Tet-
rahedron: Asymmetry 2002, 13, 1209. d) Sahasrabudhe, K.; Gracias,
V.; Furness, K.; Smith, B. T.; Katz, C. E.; Reddy, D. S.; Aubé, J. J.
Am. Chem. Soc. 2003, 125, 7914.e) Rao, D. S.; Reddy, T. R.; Babachꢀ
ary, K.; Kashyap, S. Org. Biomol. Chem. 2016, 14, 7529. f)
Chmielewski, M. K.; Tykarska, E.; Markiewicz, W. T.; Rypniewski,
W. New J. Chem. 2012, 36, 603.
（15）a) Hamilton, D. S.; Nicewicz, D. A. J. Am. Chem. Soc. 2012,
134, 18577. b) Romero, N. A.; Nicewicz, D. A. Chem. Rev. 2016, 116,
10075. c) Zhang, G.; Hu, X.; Chiang, C.ꢀW.; Yi, H.; Pei, P.; Singh, A.
K.; Lei, A. J. Am. Chem. Soc. 2016, 138, 12037. d) Yi, H.; Niu, L.;
Song, C.; Li, Y.; Dou, B.; Singh, A. K.; Lei, A. Angew. Chem. Int. Ed.
2017, 56, 1120. e) Hu, X.; Zhang, G.; Bu, F.; Lei, A. ACS Catal. 2017,
7, 1432. f) McManus, J. B.; Nicewicz, D. A. J. Am. Chem. Soc. 2017,
139, 2880.
（16）a) Fukuzumi, S.; Ohkubo, K.; Suenobu, T.; Kato, K.; Fujitsuka,
M.; Ito, O. J. Am. Chem. Soc. 2001, 123, 8459. b) Fukuzumi, S.; Koꢀ
tani, H.; Ohkubo, K.; Ogo, S.; Tkachenko, N. V.; Lemmetyinen, H. J.
Am. Chem. Soc. 2004, 126, 1600. c) Ohkubo, K.; Mizushima, K.; Iwaꢀ
ta, R.; Souma, K.; Suzuki, N.; Fukuzumi, S. Chem. Commun. 2010, 46,
601.
（17）a) Roth, H. G.; Romero, N. A.; Nicewicz, D. A. Synlett. 2016,
27, 714. b) Romero, N. A.; Margrey, K. A.; Tay, N. E.; Nicewicz, D.
A. Science 2015, 349, 1326.
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23
24
25
26
27
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31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
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（18）Margrey, K. A.; Nicewicz, D. A. Acc. Chem. Res. 2016, 49,
1997.
（19）Arnold, D. R.; Chan, M. S.; McManus, K. A. Can. J. Chem.
1996, 74, 2143.
（20）Alfassi, Z. B.; Harriman, A.; Huie, R. E.; Mosseri, S.; Neta, P.
J. Phs. Chem. 1987, 91, 2120.
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ACS Catalysis
Table of contents (TOC)
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Acr+MesClO4- (3 mol%)
R4
R4
R3
N3
HO
R1
R1
toluene (0.05 M)
TMSN3
R3 +
R2
blue LEDs, r.t.
air, 4 h
then reduction
R2
R1, R2, R3, R4
46 examples
46 - 99% yields
= aryl, alkyl, H
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