Silver-mediated direct trifluoromethoxylation of α-diazo esters: Via the -OCF3 anion

Article abstract of DOI:10.1039/c6cc03040h

Silver-mediated direct trifluoromethoxylation of α-diazo esters and ketosteroid was disclosed. The reactions of alkyl α-diazo arylacetates with AgOCF₃ or CF₃SO₂OCF₃/AgF at -30 to 10 °C under a N₂ atmosphere provided α-trifluoromethoxyl arylacetates in up to 90% yield, while alkyl α-diazo vinylacetates reacting with CF₃SO₂OCF₃/AgF or AgOCF₃ afforded γ-trifluoromethoxyl α,β-unsaturated esters in up to 94% yield. The α-diazo ketosteroid was also trifluoromethoxylated under the standard reaction conditions. This protocol allows for an effective and convenient access to a large number of synthetic building blocks, which are promising in the development of new functional OCF₃-molecules.

Full text of DOI:10.1039/c6cc03040h

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Silver-Mediated Direct Trifluoromethoxylation of α-Diazo Esters
by −OCF3 Anion
Gao-Feng Zha, Jia-Bin Han, Xiao-Qian Hu, Hua-Li Qin,* Wan-Yin Fang and Cheng-Pan Zhang*
Received 00th January 20xx,
Accepted 00th January 20xx
DOI: 10.1039/x0xx00000x
www.rsc.org/
fluorodesulfurization of carbonodithioate.6,7 These protocols have
A silver-mediated direct trifluoromethoxylation of α-diazo esters
and ketosteroid was disclosed. The reactions of alkyl α-diazo
arylacetates with AgOCF3 or CF3SO2OCF3 / AgF at -30 to 10 oC
under a N2 atmosphere provided α-trifluoromethoxyl arylacetates
in up to 90% yield, while alkyl α-diazo vinylacetates reacting with
CF3SO2OCF3 / AgF or AgOCF3 afforded γ-trifluoromethoxyl α,β-
unsaturated esters in up to 94% yield. The α-diazo ketosteroid was
also trifluoromethoxylated under the standard reaction
conditions. This protocol allows for an effective and convenient
access to a large number of synthetic building blocks which are
promising in the development of new functional OCF3-molecules.
limitations such as the use of highly toxic HF, SbF3, or SF4, and the
narrow functional group tolerance. Later, electrophilic
trifluoromethylation of alcohols and phenols by Umemoto or
Togni’s reagents was employed to produce R-OCF3, which was
subjected to harsh reaction conditions, poor substrate scope, or low
efficiency.8 The silver-mediated oxidative trifluoromethylation of
phenols and alcohols by TMSCF3 was also applied to prepare
trifluoromethyl ethers, which, nevertheless, requires a large excess
of expensive additives.9 Very recently, a two-step route to ArOCF3
was achieved by trifluoromethylation of protected N-(hetero)aryl-
N-hydroxylamines followed by intramolecular rearrangement of the
N-OCF3 intermediates; however, this reaction could only be applied
to N-arylhydroxylamines.10
OCF3-containing organic frameworks have attracted great
interests in the recent years.1 Such compounds have been
extensively exploited in medicinal chemistry, agrochemical industry,
and materials science, due to the unique stereoelectronic
properties and the excellent lipophilicity of the OCF3
substituents.1-3 The introduction of OCF3 groups into biologically
active molecules can improve their in vivo uptake and transport,
and enhance their efficacy and minimize the side effects.1,2 The
incorporation of OCF3 moiety into materials can widen the
temperature range of liquid state of materials under ambient
pressure and lower their surface tension and dielectric constants,
which are the key to the development of high performance liquid
crystals and semiconductors.[1a,3] In view of these wide
applications, the exploration of efficient methods for the synthesis
of OCF3-containing organofluorines is of great importance.
−
The direct nucleophilic trifluoromethoxylation using OCF3 as the
Although the huge advances have been made in transition-metal-
mediated formation of C-F, C-CF3, C-CF2R, C-SCF3, and C-SCF2R
bonds,4 methods for the direct construction of C-OCF3 bonds are
still lacking, with the trifluoromethoxy group being the least well
understood.1-3 The conventional preparation of OCF3-containing
molecules mainly relied on the chlorine/fluorine exchange of
trichloromethoxylated precursors.1,5 Alternative approaches
involved the deoxyfluorination of fluoroformates and the oxidative
OCF3 sources has provided
a
straightforward access to
trifluoromethyl ethers.11 Owing to the inherent instability of the
−OCF3 anion,11 there have been few reports on transition-metal-
mediated trifluoromethoxylation with “−OCF3” reagents. To seek
out
metal-OCF3
complexes
that
are
suitable
for
trifluoromethoxylation,12 we first synthesized N-heterocyclic
carbene stabilized (NHC)CuOCF3 and (NHC)AuOCF3 from
acetonitrile-solvated AgOCF3 reagent.12a The first silver-mediated
cross coupling of arylstannanes or arylboronic acids with
[TAS][OCF3]
and
the
recent
palladium-catalyzed
School of Chemistry, Chemical Engineering and Life Science, Wuhan University of
Technology, 205 Luoshi Road, Wuhan, China, 40003
E-mail: qinhuali@whut.edu.cn; cpzhang@whut.edu.cn.
.† Electronic Supplementary Information (ESI) available: [details of any
supplementary information available should be included here]. See
DOI: 10.1039/x0xx00000x
trifluoromethoxylation of prefunctionalized alkenes by AgOCF3 have
represented the state-of-the-art methods for transition-metal-
mediated nucleophilic trifluoromethoxylation to date.13 Besides, no
other reactions with “−OCF3” reagents mediated by a certain
transition-metal have been reported. Hence, the transition-metal-
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mediated direct trifluoromethoxylation with thermally unstable at 10 oC, 2a was furnished in 89% yield (see SI, Table 2), but the
−OCF3 anion is much challenging.
reaction is severe and releases a great amount of gasses, which
limits its use on large scales. Furthermore, if AgF (2 equiv.) was
added into a mixture of 1a, CF3SO2OCF3 (8 equiv.), and MeCN at -30
On the other hand, α-diazo compounds have been explosively
utilized to construct cyclopropanes, heterocycles, hydrazones,
tetrasubstituted olefins, and other functional molecules in the past
few years.14-18 The combination of α-diazo compounds with fluorine
chemistry has also achieved great successes, e.g., the Cu-mediated
o
oC and reacted at 10 C overnight, the reaction provided 2a in 76%
yield (see SI, Table 2).
In addition, the molar ratio of 1a, AgF, and CF3SO2OCF3 have a
trifluoromethylation or trifluoromethylthiolation of α-diazo esters significant impact on the reaction. For example, treatment of 1a
by TMSCF3 or AgSCF3, respectively, the Cu-mediated gem- and CF3SO2OCF3 (8 equiv) with equal equivalent of AgF gave 2a in
−
difluoroolefination of diazo compounds by TMSCF3 or Ph3P+CF2CO2 , 36% yield (see SI, Table 2), while the reaction using 3 or 5 equiv of
and the metal-free gem-difluoroolefination of diazo compounds by AgF afforded 2a in 84% or 92% yield, respectively (see SI, Table 2).
TMSCF3, TMSCF2Br, or TMSCF2Br / TBAB, which have furnished a The reaction of 1a with 2 equiv of AgF and 5 equiv of CF3SO2OCF3
variety of useful functionalized feedstocks.19 Given the unique provided 2a in 76% yield (see SI, Table 2). If 1a reacted with
properties of −OCF3 anion and the versatility of α-diazo compounds, CF3SO2OCF3 (8 equiv) in the absence of AgF, no 2a was produced
we envisioned whether the direct trifluoromethoxylation of α-diazo (see SI, Table 2). When 1a was treated with CF3SO2OCF3 (8 equiv) in
esters with “−OCF3” reagents may be a facile way to form α-OCF3 the presence of [TAS][Me3SiF2] (2 equiv), CsF (2 equiv), KF (2 equiv),
carbonyls.
or [Me4N]F (2 equiv) in CH3CN, 2a was hardly formed (see SI, Table
3). Nevertheless, if Ag2CO3 or Ag2O was added into a reaction
mixture of 1a, [Me4N]F (2 equiv), and CF3SO2OCF3 (8 equiv), 2a was
obtained in 32% or 23% yield, respectively (see SI, Table 3). All
these indicated that the silver is indispensable for the
trifluoromethoxylation reaction.
Table
1 Trifluoromethoxylation of alkyl α-diazo arylacetates with
CF3SO2OCF3 / AgF reagents a
Next, a combination of 1a / AgF (2.0 equiv) / CF3SO2OCF3 (5.0
equiv) / CH3CN / -30 to 10 oC / N2 / overnight was chosen as the
standard reaction conditions to test the scope of the reaction. To
our delight, ethyl α-diazo arylacetates with various electron-
donating or weakly electron-withdrawing groups such as CH3, OCH3,
F, Cl, Br, t-Bu, and C6H5 were all successfully transformed which
furnished the corresponding α-trifluoromethoxyl arylacetates (2b-
o) in good yields (Table 1). The position of the substituents on the
phenyl rings has considerable influence on the reaction. The ortho-
and/or para-substitution on the phenyl rings of α-diazo esters gave
higher yields of the products (e.g. 2c, 2e, 2f, and 2i), whereas the
meta-substitution
moderately
frustrated
the
trifluoromethoxylation, which provided slightly lower yields of the
products (e.g. 2d, 2g, and 2h). Moreover, the highly electron-poor
ethyl 2-diazo-2-(3-nitrophenyl)acetate (1p) reacting with
CF3SO2OCF3 and AgF under the standard reaction conditions
afforded 2p in 27% yield. Treatment of ethyl 2-diazo-2-(naphthalen-
2-yl)acetate (1q) and ethyl 2-(benzodioxol-5-yl)-2-diazoacetate (1r)
with CF3SO2OCF3 / AgF supplied 2q in 67% yield and 2r in 72% yield,
respectively. Heteroaromatic α-diazo esters, such as ethyl 2-diazo-
2-(thiophen-3-yl)acetate (1s) and ethyl 2-diazo-2-(1-tosyl-1H-indol-
3-yl)acetate (1t), reacted with CF3SO2OCF3 and AgF to afford
respective 2s in 55% yield and 2t in 90% yield. Other alkyl α-diazo
esters like methyl, propyl, isopropyl, butyl, tert-butyl, benzyl, allyl,
and adamantanyl α-diazo phenylacetates were also readily
converted under the standard reaction conditions to form 2u-2bb in
53-90% yields. Furthermore, the reaction of (1S,2R,5S)-2-isopropyl-
5-methylcyclohexyl 2-diazo-2-phenylacetate (1cc) with CF3SO2OCF3
/ AgF provided 2cc in 71% yield with a dr value of 1.1 : 1, which was
determined by 1H and 19F NMR spectroscopy (see SI).
a
Reaction conditions: CF3SO2OCF3 (2.5 mmol) was added into a mixture of 1 (0.5
mmol), AgF (1.0 mmol), and CH3CN (2.5 mL) at -30 oC in one portion via syringe under a
N2 atmosphere. After 5 mins, the reaction mixture was warmed to 10 oC overnight.
Isolated yields.
To verify this, the reaction of ethyl 2-diazo-2-(naphthalen-1-
yl)acetate (1a) with AgOCF3 was explored. It was found that
addition of 2 equiv of AgOCF3 (0.5 or 1.0 M in CH3CN) into a mixture
of 1a and CH3CN at 10 oC under a N2 atmosphere afforded 2a in
43% yield (see SI, Table 1). Using 4 equiv of AgOCF3 in the same
reaction, 2a was obtained in 53% yield (see SI, Table 1). Increasing
the reaction temperature from 10 to 25 oC, no remarkable change
in the yield of 2a was observed (58%, see SI, Table 1). Inverse
addition of 1a into 2 or 4 equiv of AgOCF3 provided 2a in 38% or
60% yield, respectively (see SI, Table 1). Since AgOCF3 was prepared
by the reaction of CF3SO2OCF3 with AgF in CH3CN,[12,13b] the
convenient one-pot reaction of 1a with CF3SO2OCF3 and AgF was
harnessed. Intriguingly, addition of 1a into a mixture of AgF (2
equiv.), CF3SO2OCF3 (8 equiv.), and MeCN at -30 oC and reacted at
10 oC overnight provided 2a in 58% yield (see SI, Table 2), while
introducing CF3SO2OCF3 (8 equiv.) into the mixture of 1a, AgF (2
equiv.), and MeCN at -30 oC and reacted at 10 oC overnight
produced 2a in 77% yield (see SI, Table 2). If CF3SO2OCF3 was added
Besides, α-diazo vinylacetates are suitable substrates to the
reaction (Table 2). When (E)-ethyl 2-diazo hex-3-enoate (3a), hept-
3-enoate (3b), and oct-3-enoate (3c) were treated with CF3SO2OCF3
and AgF at -30 to 10 oC under a N2 atmosphere overnight, 4a, 4b,
and 4c were obtained in 89%, 72%, and 94% yields, respectively.
(E)-Methyl 2-diazo non-3-enoate (3d) reacting with CF3SO2OCF3
/
AgF under the standard reaction conditions gave 4d in 91% yield.
Treatment of (E)-ethyl 2-diazo-4-phenylbut-3-enoate (3e) with
CF3SO2OCF3 and AgF afforded 4e in 82% yield. Moreover, the
2 | J. Name., 2012, 00, 1-3
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reaction of 3b with AgOCF3 (5 equiv) at 10 oC under a N2 water (or moisture) after trifluoromethoxylation to give the desired
atmosphere overnight could also generate 4b (83% yield). products. However, the details still remain unclear.
Remarkably, α-diazo ketosteroid 3f reacted with CF3SO2OCF3 (8
equiv) / AgF (5 equiv) in CH2Cl2 or with AgOCF3 (5 equiv) in CH2Cl2 /
CH3CN providing 4f in 48% or 30% yield, respectively.20 The silver-
mediated trifluoromethoxylation seems to happen at the
vinylogous position of 3 to form γ-substituted α,β-unsaturated
carbonyls, which was determined by NMR analysis of the
products.20 The geometry of 4a-e (E-isomers) can be confirmed by
the values of the coupling constants between the vinyl protons of
3
the products in 1H NMR spectra (e.g. Jtrans-HH = 15.7 Hz, see SI)
according to the literatures.21
Table 2 Trifluoromethoxylation of α-diazo vinyl carbonyls with CF3SO2OCF3 /
AgF reagents a
Scheme 1 Trifluoromethoxylation of α-diazo esters by CF3SO2OCF3 / AgF in
the presence of D2O or TEMPO
Scheme
2
Proposed reaction mechanism for silver-mediated
a Reaction conditions: CF3SO2OCF3 (2.5 mmol) was introduced into a mixture of 3 (0.5
mmol), AgF (1.0 mmol), and CH3CN (2.5 mL) at -30 oC in one portion via syringe under a
N2 atmosphere. After 5 mins, the reaction mixture was warmed to 10 oC overnight.
trifluoromethoxylation of α-diazo esters
In conclusion, we have developed an effective and convenient
method for the synthesis of trifluoromethoxylated esters and
steroid under the mild reaction conditions. In this approach,
numerous alkyl α-diazo arylacetates were converted to give the
corresponding α-trifluoromethoxyl esters in good to high yields. In
the cases of alkyl α-diazo vinylacetates, the silver-mediated reaction
exhibited good region- and stereoselectivity, which provided γ-
trifluoromethoxyl (E)-α,β-unsaturated esters in excellent yields. For
α-diazo ketosteroid, the desirable trifluoromethoxylated product
was also obtained in moderate yield. This promising and
operationally simple protocol has supplied a number of synthetic
building blocks for the development of new functional molecules,
which would render the direct trifluoromethoxylation viable to a
broader synthetic community. The application of this strategy to
other nucleophilic trifluoromethoxylation is currently under way in
our lab.
b
Isolated yields. 3b was added into a solution of AgOCF3 (5 equiv) in CH3CN at 10 oC
c
under a N2 atmosphere, and the mixture was reacted overnight. CF3SO2OCF3 (0.8
mmol) / 3f (0.1 mmol) / AgF (0.5 mmol) / CH2Cl2 (0.5 mL). d A solution of 3f (0.1 mmol)
in CH2Cl2 was added into a solution of AgOCF3 (0.5 mmol) in CH3CN.
To gain some insights into the reaction mechanism, several
control experiments were performed (Scheme 1). Initially, the
reaction of 1a, AgF (2 equiv), and CF3SO2OCF3 (5 equiv) in CD3CN
under the standard reaction conditions gave 2a in 80% yield with
13% of deuterated form, implying that acetonitrile is not the major
“proton source” for 2a. Nevertheless, if 1.1 equiv of D2O was added
into a mixture of 1a, AgF (5 equiv), CF3SO2OCF3 (8 equiv), and
CH3CN under the standard reaction conditions, 2a was obtained in a
lower yield but with much higher percentage of deuterated form
(Condition B: 33% yield, 88% D-form, Scheme 1). If a mixture of 1a,
AgF (5 equiv), CF3SO2OCF3 (8 equiv), and CH3CN was reacted at -30
o
to 10 C overnight and quenched by D2O, 91% yield of 2a with 74%
of D-form was produced (Condition C, Scheme 1). Similar results
were also observed in the case of 3c with CF3SO2OCF3 / AgF under
the standard reaction conditions. These suggest that the
trifluoromethoxylation is sensitive to moisture, which is attributed
to the in situ generation of ‒OCF3 species, and, most importantly,
that the α-proton of 2a (or 4c) might dominantly originate from
water or moisture during the workup. Since the addition of 2 equiv
of TEMPO into the reaction mixture of 1a, AgF, CF3SO2OCF3, and
CH3CN under the standard reaction conditions rarely prohibited the
formation of 2a, the radical process might be excluded in the
We thank Wuhan University of Technology, the Natural Science
Foundation of Hubei Province (China) (2015CFB176), and the
“Chutian Scholar” Program from the Department of Education of
Hubei Province (China) for financial support.
Notes and references
1. (a) P. Kirsch, Modern Fluoroorganic Chemistry : Synthesis, Reactivity, Applications, 2nd
ed. Wiley-VCH, Weinheim, 2013; (b) F. R. Leroux, B. Manteau, J. P. Vors, S. Pazenok,
Beilstein J. Org. Chem., 2008, 4, DOI: 10.3762/bjoc.4.13; (c) K. N. Lee, J. W. Lee, M. –Y.
Ngai, Synlett, 2016, 27, 313-319; (d) H. Wang, D. Vicic, A. Synlett, 2013, 24, 1887-
1898; (e) J. –H. Lin, Y. –L. Ji, J. –C. Xiao, Curr. Org. Chem. 2015, 19, 1541-1553; (f) F. R.
Leroux, P. Jeschke, M. Schlosser, Chem. Rev. 2005, 105, 827-856.
reaction. Based on these,
a plausible nucleophilic reaction
mechanism was suggested in Scheme 2. At the beginning,
CF3SO2OCF3 reacting with AgF in situ forms ionic AgOCF3. The Ag+
ion first integrates with α-diazo esters generating the key
intermediate 5a or 5b. Trifluoromethoxylation of 5a or 5b by free
‒OCF3 anion produces 6a or 6b, respectively, which is quenched by
2. (a) P. Jeschke, E. Baston, F. R. Leroux, Mini-Rev. Med. Chem. 2007, 7, 1027-1034; (b)
B. Manteau, S. Pazenok, J. P. Vors, F. R. Leroux, J. Fluorine Chem. 2010, 131, 140-158;
(c) G. Landelle, A. Panossian, F. R. Leroux, Curr. Top. Med. Chem. 2014, 14, 941-951;
(d) D. Federsel, A. Herrmann, D. Christen, S. Sander, H. Willner, H. Oberhammer, J.
This journal is © The Royal Society of Chemistry 20xx
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Mol. Struct. 2001, 567, 127-136; (e) M. A. Mcclinton, D. A. Mcclinton, Tetrahedron,
1992, 48, 6555-6666; (f) C. Hansch, A. Leo, S. H. Unger, K. H. Kim, D. Nikaitani, E. J.
Lien, J. Med. Chem. 1973, 16, 1207-1216.
12121-12126; (c) Y. Yang, X. Wang, Y. Li, B. Zhou, Angew. Chem. Int. Ed. 2015, 54,
15400-15404; (d) R. B. Dateer, S. Chang, Org. Lett. 2016, 18, 68-71.
19. (a) M. Hu, C. Ni, J. Hu, J. Am. Chem. Soc. 2012, 134, 15257-15260; (b) M. Hu, Z. He, B.
Gao, L. Li, C. Ni, J. Hu, J. Am. Chem. Soc. 2013, 135, 17302-17305; (c) M. Hu, J. Rong,
W. Miao, C. Ni, Y. Han, J. Hu, Org. Lett. 2014, 16, 2030-2033; (d) M. Hu, C. Ni, L. Li, Y.
Han, J. Hu, J. Am. Chem. Soc. 2015, 137, 14496-14501; (e) J. Zheng, J. -H. Lin, L. –Y. Yu,
Y. Wei, X. Zheng, J. –C. Xiao, Org. Lett. 2015, 17, 6150-6153; (f) Z. Zhang, W. Yu, C.
Wu, C. Wang, Y. Zhang, J. Wang, Angew. Chem. Int. Ed. 2016, 55, 273-277.
20. (a) D. Morton, A. R. Dick, D. Ghosh, H. M. L. Davies, Chem. Commun. 2012, 48,
5838-5840; (b) C. Qin, H. M. L. Davies, Org. Lett. 2013, 15, 6152-6154; (c) X. Xu, P. Y.
Zavalij, W. Hu, M. P. Doyle, J. Org. Chem. 2013, 78, 1583-1588.
3. (a) P. Kirsch, M. Bremer, Angew. Chem. Int. Ed., 2000, 39, 4216-4235; (b) M. Mamada,
H. Shima, Y. Yoneda, T. Shimano, N. Yamada, K. Kakita, T. Machida, Y. Tanaka, S.
Aotsuka, D. Kumaki, S. Tokito, Chem. Mater. 2015, 27, 141-147.
4. Selected reviews for fluorination, fluoroalkylation, and fluoroalkylthiolation: (a) O. A.
Tomashenko, V. V. Grushin, Chem. Rev. 2011, 111, 4475-4521; (b) P. Chen, G. Liu,
Synthesis 2013, 2919-2939; (c) T. Liang, C. N. Neumann, T. Ritter, Angew. Chem. Int.
Ed. 2013, 52, 8214-8264; (d) C. -P. Zhang, Q. -Y. Chen, Y. Guo, J. -C. Xiao, Y. -C. Gu,
Coord. Chem. Rev. 2014, 261, 28-72; (e) S. Barata-Vallejo, B. Lantaňo, A. Postigo,
Chem. Eur. J. 2014, 20, 16806-16829; (f) X. Liu, C. Xu, M. Wang, Q. Liu, Chem. Rev.
2015, 115, 683-730; (g) J. Charpentier, N. Früh, A. Togni, Chem. Rev. 2015, 115, 650-
682; (h) M. –C. Belhomme, T. Besset, T. Poisson, X. Pannecoucke, Chem. Eur. J. 2015,
21, 12836-12865; (i) X. Shao, C. Xu, L. Lu, Q. Shen, Acc. Chem. Res. 2015, 48, 1227-
1236; (j) S. –M. Wang, J. –B. Han, C. –P. Zhang, H. –L. Qin, J. –C. Xiao, Tetrahedron,
2015, 71, 7949-7976.
21. (a) T. Yamazaki, T. Ichige, S. Takei, S. Kawashita, T. Kitazume, T. Kubota, Org. Lett.
2001, 3, 2915-2918; (b) E. Pretsch, P. Bühlmann, M. Badertscher, Structure
Determination of Organic Compounds, 4th Revised and Enlarged Edition, Springer-
Verlag Berlin Heidelberg, 2009.
5. (a) L. M. Yagupolskii, Dokl. Akad. Nauk SSSR 1955, 105, 100-102; (b) N. N. Yarovenko,
A. S. Vasileva, J. Gen. Chem. USSR 1959, 29, 3747-3748; (c) L. M. Yagupolskii, V. I.
Troitskaya, J. Gen. Chem. USSR 1961, 31, 845-852; (d) L. M. Yagupolskii, V. V. Orda, J.
Gen. Chem. USSR 1964, 34, 1994-1998; (e) L. M. Yagupolskii, E. B. Dyachenko, V. I.
Troitskaya, Ukrain. Khim. Zh. 1961, 27, 77-79.
6. (a) W. A. Sheppard, J. Org. Chem. 1964, 29, 1-11; (b) P. E. Aldrich, W. A. Sheppard, J.
Org. Chem. 1964, 29, 11-15; (c) W. Dmowski, R. A. Kolinski, Polish J.Chem. 1978, 52,
547-559.
7. (a) M. Kuroboshi, K. Suzuki, T. Hiyama, Tetrahedron Lett. 1992, 33, 4173-4176; (b) K.
Kanie, Y. Tanaka, M. Shimizu, M. Kuroboshi, T. Hiyama, Chem. Commun. 1997, 309-
310; (c) M. Kuroboshi, K. Kanie, T. Hiyama, Adv. Synth. Catal. 2001, 343, 235-250; (d)
R. Zriba, E. Magnier, J. –C. Blazejewski, Synlett 2009, 1131-1135.
8. (a) T. Umemoto, K. Adachi, S. Ishihara, J. Org. Chem. 2007, 72, 6905-6917; (b) S. Kyrill,
R. Koller, A. Togni, J. Org. Chem. 2008, 73, 7678-7685; (c) R. Koller, K. Stanek, D. Stolz,
R. Aardoom, K. Niedermann, A. Togni, Angew. Chem. Int. Ed. 2009, 48, 4332-4336.
9. (a) J. –B. Liu, C. Chen, L. Chu, Z. –H. Chen, X. –H. Xu, F. –L. Qing, Angew. Chem. Int. Ed.
2015, 54, 11839-11842; (b) J. –B. Liu, X. –H. Xu, F. –L. Qing, Org. Lett. 2015, 17, 5048-
5051.
10. (a) K. N. Hojczyk, P. Feng, C. Zhan, M. –Y. Ngai, Angew. Chem. Int. Ed. 2014, 53,
14559-14563; (b) P. Feng, K. N. Lee, J. W. Lee, C. Zhan, M. –Y. Ngai, Chem. Sci. 2016,
7, 424-429.
11. (a) A. A. Kolomeitsev, M. Vorobyev, H. Gillandt, Tetrahedron Lett. 2008, 49, 449-454;
(b) O. Marrec, T. Billard, J. –P. Vors, S. Pazenok, B. R. Langloisa, Adv. Synth. Catal.
2010, 352, 2831-2837; (c) O. Marrec, T. Billard, J. –P. Vors, S. Pazenok, B. R. Langlois,
J. Fluorine Chem. 2010, 131, 200-207; (d) J. Barbion, S. Pazenok, J. –P. Vors, B. R.
Langlois, T. Billard, Org. Process Res. Dev. 2014, 18, 1037-1040.
12. (a) C. –P. Zhang, D. A. Vicic, Organometallics, 2012, 31, 7812-7815; (b) S. Chen, Y.
Huang, X. Fang, H. Li, Z. Zhang, T. S. A. Horb, Z. Weng, Dalton Trans. 2015, 44, 19682-
19686.
13. (a) C. Huang, T. Liang, S. Harada, E. Lee, T. Ritter, J. Am. Chem. Soc. 2011, 133,
13308-13310; (b) C. Chen, P. Chen, G. Liu, J. Am. Chem. Soc. 2015, 137, 15648-15651.
14. Construction of cyclopropanes (selected): (a) L. Chen, M. O. Bovee, B. E. Lemma, K.
S. M. Keithley, S. L. Pilson, M. G. Coleman, J. Mack, Angew. Chem. Int. Ed. 2015, 54,
11084-11087; (b) S. Y. Shim, J. Y. Kim, M. Nam, G. –S. Hwang, D. H. Ryu, Org. Lett.
2016, 18, 160-163.
15. Construction of heterocycles (selected): (a) D. J. Lee, D. Ko, E. J. Yoo, Angew. Chem.
Int. Ed. 2015, 54, 13715-13718; (b) J. Wu, D. Wang, Y. Wan, C. Ma, Chem. Commun.
2016, 52, 1661-1664; (c) Y. –F. Liu, Z. Wang, J. –W. Shi, B. –L. Chen, Z. –G. Zhao, Z.
Chen, J. Org. Chem. 2015, 80, 12733-12739; (d) J. Wang, X. Yao, T. Wang, J. Han, J.
Zhang, X. Zhang, P. Wang, Z. Zhang, Org. Lett. 2015, 17, 5124-5127; (e) K. Liu, C. Zhu,
J. Min, S. Peng, G. Xu, J. Sun, Angew. Chem. Int. Ed. 2015, 54, 12962-12967; (f) Q. –Q.
Cheng, J. Yedoyan, H. Arman, M. P. Doyle, J. Am. Chem. Soc. 2016, 138, 44-47; (g) G.
Deng, F. Wang, S. Lu, B. Cheng, Org. Lett. 2015, 17, 4651-4653.
16. Synthesis of hydrazone (selected): (a) J. Zheng, J. Qi, S. Cui, Org. Lett. 2016, 18, 128-
131; (b) L. Li, J. –J. Chen, Y. –J. Li, X. –B. Bu, Q. Liu, Y. –L. Zhao, Angew. Chem. Int. Ed.
2015, 54, 12107-12111.
17. Synthesis of tetrasubstituted Olefins (selected): C. Zhu, G. Xu, D. Ding, L. Qiu, J. Sun,
Org. Lett. 2015, 17, 4244-4247.
18. C-H bond functionalization by diazo compounds: (a) X. Gao, B. Wu, W. –X. Huang, M.
–W. Chen, Y. –G. Zhou, Angew. Chem. Int. Ed. 2015, 54, 11956-11960; (b) B. Zhou, Z.
Chen, Y. Yang, W. Ai, H. Tang, Y. Wu, W. Zhu, Y. Li, Angew. Chem. Int. Ed. 2015, 54,
4 | J. Name., 2012, 00, 1-3
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