Perfluoroalkylation of Aryl-N,N-dimethyl Hydrazones Using Hypervalent Iodine(III) Reagents or Perfluoroalkyl Iodides

Article abstract of DOI:10.1021/acs.joc.7b00934

Radical trifluoromethylation of aryl N,N-dimethyl hydrazones using TBAI as an initiator and Togni's reagent as a trifluoromethyl radical source is described. Cascades proceed via electron-catalysis; this approach is generally more applicable to hydrazone perfluoroalkylation using perfluoroalkyl iodides as the radical precursors in combination with a base under visible-light initiation.

Full text of DOI:10.1021/acs.joc.7b00934

Subscriber access provided by CORNELL UNIVERSITY LIBRARY
Article
Perfluoroalkylation of Aryl-N,N-dimethyl Hydrazones Using
Hypervalent Iodine (III) Reagents or Perfluoroalkyl Iodides
Benjamin Janhsen, and Armido Studer
J. Org. Chem., Just Accepted Manuscript • Publication Date (Web): 18 May 2017
Downloaded from http://pubs.acs.org on May 19, 2017
Just Accepted
“Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted
online prior to technical editing, formatting for publication and author proofing. The American Chemical
Society provides “Just Accepted” as a free service to the research community to expedite the
dissemination of scientific material as soon as possible after acceptance. “Just Accepted” manuscripts
appear in full in PDF format accompanied by an HTML abstract. “Just Accepted” manuscripts have been
fully peer reviewed, but should not be considered the official version of record. They are accessible to all
readers and citable by the Digital Object Identifier (DOI®). “Just Accepted” is an optional service offered
to authors. Therefore, the “Just Accepted” Web site may not include all articles that will be published
in the journal. After a manuscript is technically edited and formatted, it will be removed from the “Just
Accepted” Web site and published as an ASAP article. Note that technical editing may introduce minor
changes to the manuscript text and/or graphics which could affect content, and all legal disclaimers
and ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors
or consequences arising from the use of information contained in these “Just Accepted” manuscripts.
The Journal of Organic Chemistry is published by the American Chemical Society.
1155 Sixteenth Street N.W., Washington, DC 20036
Published by American Chemical Society. Copyright © American Chemical Society.
However, no copyright claim is made to original U.S. Government works, or works
produced by employees of any Commonwealth realm Crown government in the course
of their duties.

Page 1 of 8
The Journal of Organic Chemistry
1
2
3
4
5
6
7
8
9
Perfluoroalkylation of Aryl-N,N-dimethyl Hydrazones Using Hyper-
valent Iodine (III) Reagents or Perfluoroalkyl Iodides
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
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
56
57
58
59
60
Benjamin Janhsen and Armido Studer*
Organisch Chemisches Institut, Westfälische WilhelmsꢀUniversität Münster, Corrensstraße 40, 48149 Münster, Germany
Supporting Information Placeholder
introduce an efficient method for transition metal free perfluoroꢀ
alkylation of hydrazones using commercially available perfluoroꢀ
alkyl iodides or the Togni reagent 2 as perfluoroalkyl radical
precursors proceeding via chain processes under electronꢀ
catalysis.14
ABSTRACT: Radical trifluoromethylation of aryl N,Nꢀdimethyl
hydrazones using TBAI as an initiator and Togni’s reagent as a
trifluoromethyl radical source is described. Cascades proceed via
electronꢀcatalysis and this approach is more generally applicable
to hydrazone perfluoroalkylation using perfluoroalkyl iodides as
radical precursors in combination with a base under visible light
initiation.
RESULTS AND DISCUSSION
For initial studies, phenyl hydrazone 3a was chosen as a test
substrate in combination with the Togni reagent 2 and results are
reported in Table 1. Tetrabutylammonium iodide (TBAI) has been
found to be an efficient initiator for electronꢀcatalyzed radical
chain processes15 and was therefore also selected for the present
study. Pleasingly, reaction of 3a with 2 (2 equiv) in 1,4ꢀdioxane
as a solvent and TBAI (0.1 equiv) at 80 °C for 2 hours provided
the target product 4a in 78% yield (Table 1, entry 1).
INTRODUCTION
Hydrazones have been studied extensively in organic chemistry
and have found wide use as pharmaceuticals,1 as intermediates in
the synthesis of ketones, amines, diazo compounds, hydrazines,
and as chiral auxiliaries.2 The incorporation of fluorinated groups
into small organic compounds has been of great interest over the
last decade. The metabolic stability3 of the CꢀF bond and the
lipophilicity of fluorinated compounds increase the bioavailability
of Fꢀcontaining pharamceuticals3,4 and agrochemicals5 and thus
enhance their activity. Moreover, fluorinated building blocks have
found their way into the field of modern materials science.6
Among the various Fꢀcontaining substituents, the trifluoromethyl
group occupies a prominent role. The introduction of the trifluoꢀ
romethyl substituent can be achieved by employing ionic chemisꢀ
try using nucleophilic or electrophilic trifluoromethylating reaꢀ
gents7 or via radical chemistry using the trifluoromethyl radical.8
Several methods have been developed over the past few years,
most of which however depend on the use of transition metals.9
Notable, hypervalent iodine (III) reagents such as the Togni reaꢀ
gents 1 and 2 have significantly contributed to the development of
synthetic methodology in modern trifluoromethylation chemistry
(Figure 1).10
Table 1. Optimization of the Trifluoromethylation of hy-
drazones.
TBAI
(equiv)
2
entry
solvent
t (hrs)
yielda
(equiv)
1
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
1.0
1.2
1.5
2.0
1.2c
0.10
0.10
0.10
0.10
0.10
0.10
0.05
0.20
0.00
0.10
0.10
0.10
0.10
0.10
dioxane
DCE
2
78%
68%
68%
43%
66%
82%
33%
55%
5%
2
2
3
MeCN
EtOAc
MeCN
EtOAc
EtOAc
EtOAc
EtOAc
EtOAc
EtOAc
EtOAc
EtOAc
EtOAc
2
4
2
5
7
6
7
7
7
8
7
9
7
Figure 1. Togni’s reagents I (1) and II (2).
10
11
12
13
14
16
16
16
24
16
63%
88%
71%
11%b
11%
Recently, there have been several reports on the trifluoromethꢀ
ylation of hydrazones using the Togni reagent 2 mediated or
catalyzed by copperꢀsalts.11 Additionally, the perfluoroalkylation
of hydrazones with perfluoroalkyl halides has been achieved by
either employing photoredox catalysis using a gold complex12 or
by an UV light mediated electron transfer process.13 We herein
ACS Paragon Plus Environment

The Journal of Organic Chemistry
Page 2 of 8
b
aYield determined by 19F NMR spectroscopy. Reaction was
start the radical chain. The trifluoromethyl radical adds to the
conducted at room temperature. cRun with reagent 1 instead of 2.
C=N double bond at the azomethine carbon atom of hydrazone 3
to give the hydrazinyl radical 4. The proton bound to the former
azomethine carbon is strongly acidified by the neighboring radical
center and deprotonation by the iodobenzoic acid anion leads to
the radical anion 5. The electron rich radical anionic intermediate
5 then propagates the chain by single electron transfer to the
Togni reagent 2 to provide the trifluoromethyl radical and the
trifluoromethylated hydrazone 4 thereby sustaining the chain.
1
2
3
4
5
6
7
8
As a side product, (1,4ꢀdioxane)ꢀ2ꢀyl orthoꢀiodobenzoate deꢀ
rived from Togni’s reagent and 1,4ꢀdioxane was detected by GCꢀ
MS analysis of the reaction mixture. To suppress formation of this
side product, other solvents were tested next. Lower yields were
achieved in 1,2ꢀdichloroethane (DCE), acetronitrile or ethyl aceꢀ
tate under otherwise identical conditions (Table 1, entries 2ꢀ4).
Whereas in acetonitrile extension of the reaction time from 2 to 7
hours did not change the outcome, in ethyl acetate the yield was
significantly improved from 43 to 82% (Table 1, entries 5, 6).
Increasing or decreasing the initiator loading provided a worse
result and without any initiator, 3a was formed in only 5% yield
(Table 1, entries 7ꢀ9). A slight excess (1.2 equiv) of the Togni
reagent 2 and 16 hours reaction time turned out to be optimal for
this transformation (Table 1, entries 10ꢀ12) and we noted that
trifluoromethylation does not proceed well at room temperature
(Table 1, entry 13). Notable, under optimized conditions, Togni
reagent 1, which is a weaker oxidant as compared to 2, delivered
only 11% of the target 3a (Table 1, entry 14).
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
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
56
57
58
59
60
The scope of the aryl hydrazone trifluoromethylation was found
to be broad and different substituents at the aromatic ring are
tolerated. Yields given in Scheme 1 correspond to isolated yields.
Because of material loss during purification due to the low boiling
point of product 4a, the isolated yield of 4a is slightly lower than
the reported NMR yield in Table 1. We encountered similar probꢀ
lems also for other trifluoromethylated hydrazones. Electron
withdrawing substituents such as halides (4b, 4c, 4l), the nitro
(4e) and an ester group (4f) as well as the trifluoromethyl group
(4i) are tolerated and the corresponding products were obtained in
good yields. Hydrazone 3g bearing a phenol moiety was successꢀ
fully converted to the corresponding product 4g, albeit yield
slightly dropped (48%). For the dimethylamino substituted hydraꢀ
zone 3h we observed competing trifluoromethylation at the aroꢀ
matic ring and the desired trifluoromethylation product 4h was
isolated in 49% yield. The disubstituted aryl hydrazones 3l and 3g
provided the target compounds 4l and 4m in moderate to good
yields.
Scheme 2. Postulated mechanism for the trifluoromethyla-
tion using Togni Reagent.
Considering the strongly reducing radical anion 5 as a chain
carrier in the hydrazone trifluoromethylation, we assumed that
perfluoroalkyl radical generation might also be achieved with
weaker oxidizing perfluoroalkyl iodides as Cꢀradical precursors.
As compared to the I(III) reagent 2, perfluoroalkyl iodides are
cheaper and the length of the perfluoroalkyl group is readily
varied by simply changing the starting iodide.
Table 2. Optimization of the perfluoroalkylation.
entry
1
solvent
dioxane
MeCN
dioxane
MeCN
CHCl3
EtOAc
EtOAc
EtOAc
EtOAc
EtOAc
EtOAc
EtOAc
base
lutidine
lutidine
lutidine
lutidine
lutidine
lutidine
lutidine
lutidine
lutidine
KOtBu
Cs2CO3
imidazole
IRF (equiv)
yielda
80%b
34%b
66%
41%b
81%b
88%b
90%
83%
75%
23%
37%
89%
2
2
2
2
2
2
3
4
5
3
3
3
2
3
4
5
6
7
8
Scheme 1. Scope of the trifluoromethylation.
9
10
11
12
The suggested mechanism is depicted in Scheme 2. The reacꢀ
tion is initiated through the reduction of the Togni reagent 2 by
TBAI which acts as formal one electron donor15,16 to generate
iodobenzoate along with the trifluoromethyl radical which will
ACS Paragon Plus Environment

Page 3 of 8
The Journal of Organic Chemistry
the Togni reagent 2. This is not unexpected, since mechanistically
13
EtOAc
NEt3
3
50%
1
2
3
4
5
6
7
8
9
these two processes are very similar. Hence, halogen substituents
at the arene moiety in the starting aryl hydrazone are well toleratꢀ
ed, as documented by the successful preparation of the perfluoroꢀ
alkylated hydrazones 6b, 6c and 6n (Scheme 3). Cyano (6d) and
ester (6f) substituted aryl hydrazones worked equally well. Also
systems bearing electron donating substituents such as the tertꢀ
butyl (6j), the methoxy group (6o) and the acetal conjugated
congener (6l) reacted efficiently. As observed above for the other
process, the aminoꢀsubstituted hydrazone was partially perfluoroꢀ
alkylated at the arene ring leading to a lowering of the isolated
yield. Twofold radical perfluorobutylation in a bishydrazone was
possible (6q). The orthoꢀmethylphenyl hydrazone 3r provided the
target 6r in moderate 43% yield, likely due to steric effects. For
the naphthyl substituted hydrazone 3p the product 6p was isolated
in 46% yield. The lower yield in this case is due to the limited
solubility of the starting material in ethyl acetate. Employing
longer chain perfluoroalkyl iodides provides the corresponding
products in good yields (6sꢀu). Difluoroalkylation was achieved
by employing ethyl iododifluoroacetate. The corresponding
difluoroalkylated product 6v was obtained in 82% yield. The
proposed mechanism (Scheme 4) for this transformation resemꢀ
bles to the one proposed for the reaction employing the Togni
reagent (compare with Scheme 2). After light induced homolysis
of the IꢀRf bond (initiation) a perfluoroalkyl radical is generated
which adds to the hydrazone 3 to provide hydarzinyl radical 7.
Deprotonation of 7 by 2,6ꢀlutidine delivers the radical anion 8
which further reacts with the perfluoroalkyl iodide by SET to
product hydrazone 6 along with the perfluoroalkyl radical thereby
sustaining the chain.
aYield determined by 19F NMR spectroscopy. b5 mol % nꢀ
Bu6Sn2 was used as additive.
Along these lines, we continued the studies with hydrazone 3a
as test substrate in combination with commercial perfluorobutyl
iodide as the Rfꢀradical precursor. Since the iodide anion generatꢀ
ed in the SET reduction of a perfluoroalkyl iodide is a very weak
base, a stoichiometric external base has to be added to run such a
cascade. For reaction optimization, solvent and base were systemꢀ
atically varied (Table 2). We found that the chain can be readily
initiated by simple visible light irradiation of the reaction mixture
(50 °C). In first attempts the cascade was performed in the presꢀ
ence of hexabutyl ditin as an additive to trap molecular iodine
which is formed after CꢀI homolysis of the alkyl iodide during
initiation.17 We were pleased to find that reaction of 3a with IC4F9
(2 equiv) worked well in 1,4ꢀdioxane with 2,6ꢀlutidine as a base
(3 equiv) and the desired product 6a was formed in 80% yield
(Table 2, entry 1). A similar yield was achieved in acetonitrile but
reaction in CHCl3 was less efficient (Table 2, entries 2, 4 and 5).
In the absence of hexabutyl ditin in 1,4ꢀdioxane, yield slightly
dropped (Table 2, entry 3). Upon switching to EtOAc as a solvent,
the yield could be increased to 88% (Table 2, entry 6) and increasꢀ
ing the excess of perfluoroalkyl iodide to 3 equivalents in the
absence of any ditin gave the product in 90% yield (Table 2, entry
7). A further increase of the amount of perfluorobutyl iodide led
to worse results (Table 2, entries 8 and 9). Other bases such as
cesium carbonate or potassium tertꢀbutoxide provided lower
yields, likely due to solubility problems (Table 2, entries 10 and
11). However, lutidine can be replaced by imidazole without
affecting the reaction outcome, but triethylamine provided a lower
yield (Table 2, entries 12 and 13).
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
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
56
57
58
59
60
Scheme 4. Postulated mechanism for the hydrazone per-
fluoroalkylation using perfluoroalkyl iodides.
CONCLUSION
In summary, two related synthetic methods for the transition
metal free preparation of perfluoroalkylated N,Nꢀdimethyl hydraꢀ
zones were introduced by either using the Togni reagent 2 in
combination with TBAI as an initiator or perfluoroalkyl iodides
under visible light initiation. The starting hydrazones are readily
accessed and perfluoroalkylated products are valuable comꢀ
pounds. The two methods introduced are complementary: Whereꢀ
as the Togni reagent is certainly more expensive as compared to
the perfluoroalkyl iodides used in the second process, for the
trifluoromethylation the first process using the Togni reagent is
recommended due to high volatility of the trifluoromethyl iodide
which renders experimentation difficult. However, for the higher
homologues for which the corresponding Togni typeꢀreagent is
a5 molꢀ% of Bu6Sn2 was added.
Scheme 3. Scope of the perfluoroalkylation.
With optimized conditions in hand, the reaction scope was inꢀ
vestigated. The hydrazone moiety was varied first keeping noꢀ
nafluorobutyl iodide as the Cꢀradical precursor. Reactivity trends
observed resemble those noted for the trifluoromethylation using
ACS Paragon Plus Environment

The Journal of Organic Chemistry
Page 4 of 8
either not commercially available (for example C2F5 and C3F7)18
1H NMR (400 MHz, CDCl3, 300 K): δ (ppm) = 7.42 (s, 4H), 7.14
(s, 1H), 2.97 (s, 6H). HRMS (ESI): calcd for [C9H11BrN2H]+:
1
2
3
4
5
6
7
8
or unknown (CnF2n+1, n > 3), the second process is clearly faꢀ
vored. Both cascades proceed via radical chain reactions under
electronꢀcatalysis.14a Reactions show broad substrate scope and
yields obtained are generally good.
m/z = 227.0184; found: m/z = 227.0180.
4ꢀCyanobenzaldehyde N,Nꢀdimethylhydrazone 3d. According
to general procedure 1 using 4ꢀcyanobenzaldehyde (197 mg,
1.5 mmol, 1.00 equiv). Crystallization from hot EtOH yielded the
hydrazone as colorless crystals (207 mg, 80%). 1H NMR
(300 MHz, CDCl3, 300 K): δ (ppm) = 7.70 – 7.46 (m, 4H), 7.07
(s, 1H), 3.06 (s, 6H). HRMS (ESI): calcd for [C10H11N3Na]+:
m/z = 196.0851; found: m/z = 196.0836.
EXPERIMENTAL SECTION
General methods. All reactions involving airꢀ or moisture senꢀ
sitive reagents were carried out in flame dried glass ware under an
atmosphere of argon. CH2Cl2 was freshly distilled from P2O5
under argon. All other solvents and reagents were purified accordꢀ
ing to standard procedures or were used as received from Sigma
9
4ꢀNitrobenzaldehyde N,Nꢀdimethylhydrazone 3e. According to
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
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
56
57
58
59
60
general procedure
1
using 4ꢀnitrobenzaldehyde (227 mg,
1.5 mmol, 1.00 equiv). Purification by FCC (30% CH2Cl2 in
pentane) yielded the hydrazone as bright orange crystals (248 mg,
1
Aldrich, Acros, Alfa Aesar or TCI Europe. H NMR, 19F NMR
1
3
and 13C NMR spectra were recorded on a Bruker DPX 300 at
300 K. 19F decoupled 13C NMR spectra were recorded on an
Agilent DD2 600 at 299 K. All resonances are reported relative to
TMS. Spectra were calibrated relative to the solvent’s residual
proton and carbon chemical shift. Coupling constants (J) are
reported in Hz. Trifluorotoluene was used as internal standard for
determining the reaction yield by 19F NMR (optimization studies).
Mass spectra were recorded on a Finnigan MAT 4200S, a Bruker
Daltonics Micro Tof, a WatersꢀMicromass Quatro LCZ (ESI);
peaks are given in m/z (% of basis peak). ESI–MS (m/z) and
HRMS (m/z) were performed using a Bruker MicroTof (loop
injection; resolution: 10,000), a LTQ Orbitrap XL (nanospray
inlet, 1.1 KV, resolution: (30,000), and an Autoflex Speed TOFꢀ
MS (Bruker Daltonics). TLC was performed to monitor reactions
using Merck silica gel 60 Fꢀ254 plates and detection of comꢀ
pounds was done using UV light. Flash column chromatography
(FCC) was performed using Merck silica gel 60 (40ꢀ63 µm) to
purify products applying a pressure of about 0.2 bar. The fluoriꢀ
nated hydrazones were purified by MPLC using a Grace Davison
Reveleris IES Flash Chromatography System with Reveleris C18
ReversedꢀPhase Flash Carttridges (12 g) and a flow rate of
30 mL/min and CH3CN/H2O as solvent mixture.
86%). H NMR (300 MHz, CDCl3, 300 K): δ (ppm) = 8.15 (d, J
3
= 8.8 Hz, 2H), 7.63 (d, J = 8.8 Hz, 2H), 7.10 (s, 1H), 3.10 (s,
6H). HRMS (ESI): calcd for [C9H11N3O2Na]+: m/z = 216.0749;
found: m/z = 216.0741.
Methyl ((2,2ꢀdimethylhydrazono)methyl)benzoate 3f. According
to general procedure 1 using Methyl 4ꢀformylbenzoate (246 mg,
1.5 mmol, 1.00 equiv). Purification by FCC (10% EtOAc in penꢀ
tane) yielded the hydrazone as colorless liquid (265 mg, 86%). 1H
3
NMR (300 MHz, CDCl3, 300 K): δ (ppm) = 7.97 (d, J = 8.5 Hz,
3
2H), 7.59 (d, J = 8.5 Hz, 2H), 7.16 (s, 1H), 3.90 (s, 3H), 3.03 (s,
6H). HRMS (ESI): calcd for [C11H14N2O2Na]+: m/z
229.0953; found: m/z = 229.0945.
=
4ꢀHydroxybenzaldehyde N,Nꢀdimethylhydrazone 3g. According
to general procedure 1 using 4ꢀhydroxybenzaldehyde (183 mg,
1.5 mmol, 1.00 equiv). Purification by FCC (10% acetone in
1
pentane) yielded the hydrazone as tan solid (217 mg, 88%). H
NMR (300 MHz, acetoneꢀd6, 300 K): δ (ppm) = 8.36 (s, 1H), 7.43
3
3
(d, J = 8.7 Hz, 2H), 7.29 (s, 1H), 6.79 (d, J = 8.7 Hz, 2H), 2.85
(s, 6H). HRMS (ESI): calcd for [C9H12N2OH]+: m/z = 165.1022;
found: m/z = 165.1035.
4ꢀDimethylaminobenzaldehyde N,Nꢀdimethylhydrazone 3h. Acꢀ
cording
to
general
procedure
1
using
4ꢀ
General procedure 1 for the synthesis of hydrazones 3. Folꢀ
lowing a procedure by Ros et al.17 the benzaldehyde derivative
(1.5 mmol, 1.00 equiv) was dissolved in a suspension of anhyꢀ
drous MgSO4 (361 mg, 3.00 mmol, 2.00 equiv) in CH2Cl2
(10 mL). 1,1ꢀDimethylhydrazine (225 µL, 3.00 mmol, 2.00 equiv)
was added and the reaction was stirred for 16 h at room temperaꢀ
ture. The MgSO4 was filtered off and the volatiles were removed
in vacuo. The pure hydrazone was obtained after flash column
chromatography.
dimethylaminobenzaldehyde (224 mg, 1.5 mmol, 1.00 equiv).
Purification by FCC (5% acetone in pentane) yielded the hydraꢀ
1
zone as brown solid (177 mg, 62%). H NMR (400 MHz, CDCl3,
300 K): δ (ppm) = 7.47 (d, 3J = 8.8 Hz, 2H), 7.31 (s, 1H), 6.70 (d,
3J = 8.8 Hz, 2H), 2.96 (s, 6H), 2.89 (s, 6H). HRMS (ESI): calcd
for [C11H17N3H]+: m/z = 192.1501; found: m/z = 192.1484,
calcd for [C11H17N3Na]+: m/z = 214.1320; found: m/z =
214.1310.
4ꢀTrifluoromethylbenzaldehyde N,Nꢀdimethylhydrazone 3i. Acꢀ
Benzaldehyde N,Nꢀdimethylhydrazone 3a. According to general
procedure 1 using benzaldehyde (153 µL, 1.5 mmol, 1.00 equiv).
Purification by FCC (10% MTBE in pentane) yielded the hydraꢀ
zone as colorless liquid (191 mg, 86%). 1H NMR (300 MHz,
CDCl3, 300 K): δ (ppm) = 7.64 – 7.52 (m, 2H), 7.39 – 7.17 (m,
4H), 2.98 (s, 6H). 13C NMR (75 MHz, CDCl3, 300 K): δ (ppm) =
128.6, 127.7, 125.9, 43.1. HRMS (ESI): calcd for [C9H12N2H]+:
m/z = 149.1073; found: m/z = 149.1076.
cording
to
general
procedure
1
using
4ꢀ
trifluoromethylbenzaldehyde (180 mg, 1.03 mmol, 1.00 equiv)
with 1,1ꢀDimethylhydrazine (150 µL, 2.07 mmol, 2.00 equiv) and
MgSO4 (240 mg, 2.07 mmol, 2.00 equiv). Purification by FCC
(5% MTBE in pentane) yielded the hydrazone as colorless solid
1
(179 mg, 80%). H NMR (300 MHz, CDCl3, 300 K): δ (ppm) =
3
3
7.64 (d, J = 8.2 Hz, 2H), 7.55 (d, J = 8.2 Hz, 2H), 7.16 (s, 1H),
3.03 (s, 6H). 19F NMR (282 MHz, CDCl3, 300 K) δ (ppm) = ꢀ
62.3. HRMS (ESI): calcd for [C10H11F3N2H]+: m/z = 217.0953;
found: m/z = 217.0945.
4ꢀFluorobenzaldehyde N,Nꢀdimethylhydrazone 3b. According
to general procedure 1 using 4ꢀfluorobenzaldehyde (161 µL,
1.5 mmol, 1.00 equiv). Purification by FCC (5% EtOAc in penꢀ
tane) yielded the hydrazone a brownish solid (237 mg, 95%).
1H NMR (300 MHz, CDCl3, 300 K): δ (ppm) = 7.64 – 7.41 (m,
2H), 7.21 (s, 1H), 7.07 – 6.88 (m, 2H), 2.95 (s, 6H). 19F NMR
(282 MHz, CDCl3, 300 K) δ (ppm) = ꢀ114.8. HRMS (ESI): calcd
for [C9H11FN2H]+: m/z = 167.0985; found: m/z = 167.0955.
4ꢀtertꢀbutylbenzaldehyde N,Nꢀdimethylhydrazone 3j. According
to general procedure 1 using 4ꢀtertꢀbutylbenzaldehyde (251 µL,
1.5 mmol, 1.00 equiv). Purification by FCC (5% EtOAc in penꢀ
tane) yielded the hydrazone as colorless solid (254 mg, 83%).
1H NMR (300 MHz, CDCl3, 300 K): δ (ppm) = 7.51 (d, 3J =
3
8.4 Hz, 2H), 7.35 (d, J = 8.4 Hz, 2H), 7.27 (s, 1H), 2.94 (s, 6H),
1.32 (s, 9H). HRMS (ESI): calcd for [C13H20N2H]+: m/z =
205.1705; found: m/z = 205.1696.
4ꢀBromobenzaldehyde N,Nꢀdimethylhydrazone 3c. According
to general procedure 1 using 4ꢀbromobenzaldehyde (278 mg,
1.5 mmol, 1.00 equiv). Purification by FCC (5% EtOAc in penꢀ
tane) yielded the hydrazone as colorless solid (291 mg, 85%).
ACS Paragon Plus Environment

Page 5 of 8
The Journal of Organic Chemistry
4ꢀ(Methyl)thiobenzaldehyde N,Nꢀdimethylhydrazone 3k. Acꢀ
HRMS (ESI): calcd for [C10H14N2H]+: m/z = 163.1235; found:
1
2
3
4
5
6
7
8
cording to general procedure 1 using 4ꢀ(methyl)thiobenzaldehyde
(195 µL, 1.5 mmol, 1.00 equiv). Purification by FCC (5% MTBE
in pentane) yielded the hydrazone as colorless solid (257 mg,
88%). H NMR (300 MHz, CDCl3, 300 K): δ (ppm) = 7.49 (d, J
= 8.4 Hz, 2H), 7.26 – 7.15 (m, 3H), 2.96 (s, 6H), 2.48 (s, 3H).
HRMS (ESI): calcd for [C10H14N2SH]+: m/z = 195.0956; found:
m/z = 195.0940.
m/z = 163.1205.
General procedure 2 for the trifluoromethylation to give 4.
The corresponding hydrazone 3 (200 µmol, 1.00 equiv) was disꢀ
solved in anhydrous EtOAc (1 mL) in a flame dried pressure tube
under argon. TBAI (7.9 mg, 20 µmol, 0.10 equiv) and 2 (76.0 mg,
240 µmol, 1.20 equiv) were added and the reaction mixture was
heated to 80 °C for 16 h. After cooling down to room temperature
the mixture was filtered through a short plug of silica and the
volatiles were removed in vacuo. Purification on an MPLC sysꢀ
tem using C18ꢀreverse phase silica and CH3CN/H2O (0 min: 5%
CH3CN; 40 min: 80% CH3CN, 50 min: 90% CH3CN) as eluent
afforded analytically pure trifluoromethylated hydrazones 4.
1
3
Piperonal N,Nꢀdimethylhydrazone 3l. According to general
procedure 1 using piperonal (225 mg, 1.5 mmol, 1.00 equiv).
Purification by FCC (5% EtOAc in pentane) yielded the hydraꢀ
zone as colorless solid (243 mg, 84%). 1H NMR (300 MHz,
CDCl3, 300 K): δ (ppm) = 7.22 (d, 4J = 1.6 Hz, 1H), 7.20 (s, 1H),
6.92 (dd, 3J = 8.0, 4J = 1.6 Hz, 1H), 6.76 (d, 3J = 8.0 Hz, 1H), 5.94
(s, 2H), 2.92 (s, 6H). HRMS (ESI): calcd for [C10H12N2O2H]+:
m/z = 193.0977; found: m/z = 193.0959.
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
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
56
57
58
59
60
(Z)ꢀ1,1ꢀdimethylꢀ2ꢀ(2,2,2ꢀtrifluoroꢀ1ꢀ
phenylethylidene)hydrazine 4a. According to general procedure 2
using 3a (33 µL, 0.20 mmol, 1.0 equiv). 4a was obtained as yelꢀ
1
2,6ꢀdichlorobenzaldehyde N,Nꢀdimethylhydrazone 3m. Accordꢀ
ing to general procedure 1 using 2,6ꢀdichlorobenzaldehyde
(263 mg, 1.5 mmol, 1.00 equiv). Purification by FCC (1% MTBE
in pentane) yielded the hydrazone as colorless oil (254 mg, 78%).
low oil (30.6 mg, 71%). H NMR (600 MHz, CDCl3, 299 K): δ
(ppm) = 7.39 – 7.33 (m, 5H), 2.74 (s, 6H). 13C{1H, 19F} NMR
(151 MHz, CDCl3, 299 K): δ (ppm) = 132.2, 129.7, 129.3, 129.0,
128.1, 122.0, 46.6. 19F NMR (564 MHz, CDCl3, 299 K): δ (ppm)
= ꢀ65.7. HRMS (ESI): calcd for [C10H11F3N2H]+: m/z =
217.0953; found: m/z = 217.0966, calcd for [C10H11F3N2Na]+:
m/z = 239.0772; found: m/z = 239.0767.
3
1H NMR (300 MHz, CDCl3, 300 K): δ (ppm) = 7.30 (d, J = 8.0
Hz, 2H), 7.24 (s, 1H), 7.04 – 7.09 (m, 1H), 3.04 (s, 6H). HRMS
(ESI): calcd for [C9H10Cl2N2H]+: m/z = 217.0299; found: m/z =
217.0305, calcd for [C9H10Cl2N2Na]+: m/z = 239.0119; found:
m/z = 239.0127.
(Z)ꢀ1,1ꢀdimethylꢀ2ꢀ(2,2,2ꢀtrifluoroꢀ1ꢀ(4ꢀ
fluorophenyl)ethylidene)hydrazine 4b. According to general
procedure 2 using 3b (33.2 mg, 200 µmol, 1.00 equiv). 4b was
obtained as yellow oil (31.3 mg, 67%). 1H NMR (600 MHz,
CDCl3, 299 K): δ (ppm) = 7.34 (dd, 3J = 8.6, 5.4 Hz, 2H), 7.07 (t,
3J = 8.6 Hz, 2H), 2.75 (s, 6H). 13C{1H, 19F} NMR (151 MHz,
CDCl3, 299 K): δ (ppm) = 163.1, 131.8, 128.3, 128.2, 122.1,
115.5, 46.8. 19F NMR (564 MHz, CDCl3, 299 K): δ (ppm) = ꢀ
65.9, ꢀ111.2. HRMS (ESI): calcd for [C10H10F4N2H]+: m/z =
235.0858; found: m/z = 235.0873, calcd for [(C10H10F4N2)2H]+:
4ꢀChlorobenzaldehyde N,Nꢀdimethylhydrazone 3n. According
to general procedure 1 using 4ꢀchlorobenzaldehyde (211 mg,
1.5 mmol, 1.00 equiv). Purification by FCC (5% EtOAc in penꢀ
1
tane) yielded the hydrazone as colorless solid (216 mg, 79%). H
3
NMR (300 MHz, CDCl3, 300 K): δ (ppm) = 7.49 (d, J = 8.5 Hz,
3
2H), 7.28 (d, J = 8.5 Hz, 2H), 7.16 (s, 1H), 2.97 (s, 6H). HRMS
(ESI): calcd for [C9H11ClN2H]+: m/z = 183.0689; found: m/z =
183.0665.
m/z
=
469.1638; found: m/z
=
469.1484, calcd for
4ꢀMethoxybenzaldehyde N,Nꢀdimethylhydrazone 3o. According
to general procedure 1 using 4ꢀmethoxybenzaldehyde (180 µL,
1.5 mmol, 1.00 equiv). Purification by FCC (5% EtOAc in penꢀ
tane) yielded the hydrazone as colorless liquid (231 mg, 86%). 1H
[(C10H10F4N2)2Na]+: m/z = 491.1458; found: m/z = 491.1547.
(Z)ꢀ1,1ꢀdimethylꢀ2ꢀ(2,2,2ꢀtrifluoroꢀ1ꢀ(4ꢀ
bromophenyl)ethylidene)hydrazine 4c. According to general
procedure 2 using 3c (45.4 mg, 200 µmol, 1.00 equiv). 4c was
obtained as yellow solid (41.6 mg, 78%). 1H NMR (600 MHz,
CDCl3, 299 K): δ (ppm) = 7.52 (d, J = 8.2 Hz, 2H), 7.23 (d, J =
8.2 Hz, 2H), 2.77 (s, 6H). 13C{1H, 19F} NMR (151 MHz, CDCl3,
299 K): δ (ppm) = 131.5, 131.5, 131.3, 127.4, 123.6, 122.0, 46.9.
19F NMR (564 MHz, CDCl3, 299 K): δ (ppm) = ꢀ65.6. HRMS
(ESI): calcd for [C10H10BrF3N2H]+: m/z = 295.0058; found: m/z
= 295.0067, calcd for [(C10H10BrF3N2)2H]+: m/z = 591.0017;
found: m/z = 590.9894. Mp: 51ꢀ52 °C.
3
NMR (300 MHz, CDCl3, 300 K): δ (ppm) = 7.51 (d, J = 8.8 Hz,
3
2H), 7.26 (s, 1H), 6.87 (d, J = 8.8 Hz, 2H), 3.81 (s, 3H), 2.92 (s,
6H). HRMS (ESI): calcd for [C10H14N2OH]+: m/z = 179.1184;
found: m/z = 179.1163.
3
3
2ꢀNaphthaldehyde N,Nꢀdimethylhydrazone 3p. According to
general procedure 1 using 2ꢀnaphthaldehyde (1.56 g, 10.0 mmol,
1.00 equiv),
1,1ꢀdimethylhydrazine
(985 µL,
13.0 mmol,
1.30 equiv) and MgSO4 (1.68 g, 20.0 mmol, 2.00 equiv.). Purifiꢀ
cation by FCC (5% EtoAc in pentane) yielded the hydrazone as
1
white solid (1.52 g, 77%). H NMR (300 MHz, CDCl3, 300 K): δ
(Z)ꢀ4ꢀ(1ꢀ(2,2ꢀdimethylhydrazono)ꢀ2,2,2ꢀ
(ppm) = 7.92 – 7.89 (m, 1H), 7.81 – 7.76 (m, 4H), 7.45 – 7.50 (m,
3H), 3.03 (s, 6H). HRMS (ESI): calcd for [C13H14N2H]+: m/z =
199.1235; found: m/z = 199.1226.
trifluoroethyl)benzonitrile 4d. According to general procedure 2
using 3d (34.6 mg, 200 µmol, 1.00 equiv). 4d was obtained as
brownish solid (41.2 mg, 83%). 1H NMR (300 MHz, CDCl3,
300 K): δ (ppm) = 7.67 (d, J = 8.1 Hz, 2H), 7.47 (d, 3J = 8.1 Hz,
3
1,4ꢀPhthaldehyde N,Nꢀdimethylhydrazone 3q. According to
general procedure 1 using 1,4ꢀphthaldehyde (201 mg, 1.5 mmol,
2H), 2.80 (s, 6H). 13C{1H, 19F} NMR (151 MHz, CDCl3, 299 K):
δ (ppm) = 137.3, 131.9, 130.7, 125.3, 122.0, 118.3, 113.1, 47.2.
19F NMR (564 MHz, CDCl3, 299 K): δ (ppm) = ꢀ64.9. HRMS
(ESI): calcd for [C11H10F3N3Na]+: m/z = 264.0725; found: m/z
= 264.0709, calcd for [(C11H10F3N3)2Na]+: m/z = 505.1551;
found: m/z = 505.1496.
1.00 equiv),
1,1ꢀdimethylhydrazine
(450 µL,
6.00 mmol,
4.00 equiv) and MgSO4 (722 mg, 6.00 mmol, 4.00 equiv). Purifiꢀ
cation by FCC (10% MTBE in pentane) yielded the hydrazone as
1
yellowish crystals (280 mg, 86%). H NMR (300 MHz, CDCl3,
300 K): δ (ppm) = 7.52 (s, 4H), 7.23 (s, 2H), 2.97 (s, 12H).
HRMS (ESI): calcd for [C12H18N4H]+: m/z = 219.1610; found:
m/z = 219.1602.
(Z)ꢀ1,1ꢀdimethylꢀ2ꢀ(2,2,2ꢀtrifluoroꢀ1ꢀ(4ꢀ
nitrophenyl)ethylidene)hydrazine 4e. According to general proceꢀ
dure 2 using 3e (38.6 mg, 200 µmol, 1.00 equiv). 4e was obtained
as yellow solid (38.6 mg, 74%). 1H NMR (600 MHz, CDCl3,
2ꢀMethylbenzaldehyde N,Nꢀdimethylhydrazone 3r. According
to general procedure 1 using 2ꢀmethylbenzaldehyde (175 µL,
1.5 mmol, 1.00 equiv). Purification by FCC (5% MTBE in penꢀ
tane) yielded the hydrazone as colorless liquid (161 mg, 66%). 1H
NMR (300 MHz, CDCl3, 300 K): δ (ppm) = 7.83 – 7.71 (m, 1H),
7.43 (s, 1H), 7.24 – 7.08 (m, 3H), 2.99 (s, 6H), 2.42 (s, 3H).
299 K): δ (ppm) = 8.24 (d, J = 8.4 Hz, 2H), 7.54 (d, 3J = 8.4 Hz,
3
2H), 2.82 (s, 6H). 13C{1H, 19F} NMR (151 MHz, CDCl3, 299 K):
δ (ppm) = 148.0, 139.3, 131.0, 124.7, 123.3, 122.0, 47.3.
19F NMR (564 MHz, CDCl3, 299 K): δ (ppm) = ꢀ64.7. HRMS
ACS Paragon Plus Environment

The Journal of Organic Chemistry
Page 6 of 8
(ESI): calcd for [C10H10F3N3O2H]+: m/z = 262.0803; found: m/z
125.6, 122. 1, 46.8, 15.3. 19F NMR (564 MHz, CDCl3, 299 K): δ
= 262.0811, calcd for [C10H10F3N3O2Na]+: m/z = 284.0623;
found: m/z = 284.0636, calcd for [(C10H10F3N3O2)2Na]+: m/z =
545.1348; found: m/z = 545.1401.
(ppm) = ꢀ65.7. HRMS (ESI): calcd for [C11H13F3N2SH]+: m/z =
263.0830; found: m/z = 263.0808, calcd for [C11H13F3N2SNa]+:
m/z = 285.0649; found: m/z = 285.0642.
1
2
3
4
5
6
7
8
9
(Methyl
(Z)ꢀ4ꢀ(1ꢀ(2,2ꢀdimethylhydrazono)ꢀ2,2,2ꢀ
((Z)ꢀ2ꢀ(1ꢀ(benzo[d][1,3]dioxolꢀ5ꢀyl)ꢀ2,2,2ꢀtrifluoroethylidene)ꢀ
1,1ꢀdimethylhydrazine 4l. According to general procedure 2 using
3l (38.4 mg, 200 µmol, 1.00 equiv). 4l was obtained as brown oil
trifluoroethyl)benzoate 4f. According to general procedure 2
using 3f (41.3 mg, 200 µmol, 1.00 equiv). 4f was obtained as
brownish solid (47.4 mg, 86%). 1H NMR (600 MHz, CDCl3,
1
(28.0 mg, 54%). H NMR (600 MHz, CDCl3, 299 K): δ (ppm) =
299 K): δ (ppm) = 8.03 (d, J = 8.0 Hz, 2H), 7.43 (d, 3J = 8.0 Hz,
6.86 – 6.73 (m, 3H), 6.00 (s, 2H), 2.77 (s, 6H). 13C{1H, 19F} NMR
(151 MHz, CDCl3, 299 K): δ (ppm) = 148.4, 147.6, 129.2, 125.4,
123.9, 122.1, 110. 0, 108.2, 101.5, 46.7. 19F NMR (564 MHz,
CDCl3, 299 K): δ (ppm) = ꢀ65.9. HRMS (ESI): calcd for
[C11H11F3N2O2H]+: m/z = 261.0851; found: m/z = 261.0854,
calcd for [C11H11F3N2O2Na]+: m/z = 283.0670; found: m/z =
283.0671.
3
2H), 3.92 (s, 3H), 2.77 (s, 6H). 13C{1H, 19F} NMR (151 MHz,
CDCl3, 299 K): δ (ppm) = 166.5, 137.1, 130.8, 130.0, 129.3,
127.1, 122.1, 52.4, 47.0. 19F NMR (564 MHz, CDCl3, 299 K): δ
(ppm) = ꢀ 65.2. HRMS (ESI): calcd for [C12H13F3N2O2Na]+:
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
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
56
57
58
59
60
m/z
=
297.0827; found: m/z
=
297.0823, calcd for
[(C12H13F3N2O2)2Na]+: m/z
=
571.1756; found: m/z
=
571.1738. Mp: 68ꢀ69 °C.
(Z)ꢀ2ꢀ(1ꢀ(2,6ꢀdichlorophenyl)ꢀ2,2,2ꢀtrifluoroethylidene)ꢀ1,1ꢀ
dimethylhydrazine 4m. According to general procedure 2 using
3m (43.2 mg, 200 µmol, 1.00 equiv). 4m was obtained as dark
brown solid (43.9 mg, 77%). 1H NMR (600 MHz, CDCl3, 299 K):
δ (ppm) = 7.35 – 7.30 (m, 2H), 7.28 – 7.24 (m, 1H), 2.88 (s, 6H).
13C{1H, 19F} NMR (151 MHz, CDCl3, 299 K): δ (ppm) = 137.2,
132.2, 131.3, 127.6, 121.9, 119.1, 45.1. 19F NMR (564 MHz,
CDCl3, 299 K): δ (ppm) = ꢀ63.5. HRMS (ESI): calcd for
[C10H9Cl2F3N2Na]+: m/z = 306.9993; found: m/z = 307.0002.
(Z)ꢀ4ꢀ(1ꢀ(2,2ꢀdimethylhydrazono)ꢀ2,2,2ꢀtrifluoroethyl)phenol
4g. According to general procedure 2 using 3g (32.8 mg,
200 µmol, 1.00 equiv). 4g was obtained as brownish solid
1
(22.1 mg, 48%). H NMR (300 MHz, CDCl3, 300 K): δ (ppm) =
3
3
7.24 (d, J = 8.4 Hz, 2H), 6.84 (d, J = 8.4 Hz, 2H), 5.25 (s, 1H),
2.74 (s, 6H). 13C{1H, 19F} NMR (151 MHz, CDCl3, 299 K): δ
(ppm) = 156.4, 131.3, 130.2, 124.4, 122.1, 115.3, 46.7. 19F NMR
(564 MHz, CDCl3, 299 K): δ (ppm) = ꢀ66.0. HRMS (ESI): calcd
for [C10H11F3N2OH]+: m/z = 233.0902; found: m/z = 233.0917,
calcd for [C10H11F3N2ONa]+: m/z = 255.0721; found: m/z =
255.0749.
General procedure 3 for the perfluoroalkylation to give 6.
The corresponding hydrazone 3 (200 µmol, 1.00 equiv) was disꢀ
solved in anhydrous EtOAc (1 mL) in a flame dried pressure tube
under argon. 2,6ꢀLutidine (70 µL, 0.60 mmol, 3.0 equiv) and the
corresponding perfluoroalkyl iodide (0.60 mmol, 3.0 equiv) were
added. The reaction mixture was irradiated using a Philips Master
HPIꢀT Plus 400W/645 lamp. The temperature in the photoreactor
was around 50 °C (fan cooling). After 24 h of irradiation the
reaction mixture was filtered through a short plug of silica and the
volatiles were removed in vacuo. Purification on an MPLC sysꢀ
tem using C18ꢀreverse phase silica and CH3CN/H2O (0 min: 5%
CH3CN; 40 min: 80% CH3CN, 50 min: 90% CH3CN) as eluent
afforded analytically pure perfluoroalkylated hydrazones 6.
(Z)ꢀ4ꢀ(1ꢀ(2,2ꢀdimethylhydrazono)ꢀ2,2,2ꢀtrifluoroethyl)ꢀN,Nꢀ
dimethylaniline 4h. According to general procedure 2 using 3h
(38.3 mg, 200 µmol, 1.00 equiv). 4h was obtained as tan solid
1
(25.3 mg, 49%). H NMR (300 MHz, CDCl3, 300 K): δ (ppm) =
3
3
7.24 (d, J = 8.8 Hz, 2H), 6.67 (d, J = 8.8 Hz, 2H), 2.99 (s, 6H),
2.73 (s, 6H). 13C{1H, 19F} NMR (151 MHz, CDCl3, 299 K): δ
(ppm) = 150.7, 132.8, 130.3, 122.2, 118.8, 111.4, 46.7, 40.3.
19F NMR (564 MHz, CDCl3, 299 K): δ (ppm) = ꢀ66.0. HRMS
(ESI): calcd for [C12H16F3N3H]+: m/z = 260.1375; found: m/z =
260.1388, calcd for [C12H16F3N3Na]+: m/z = 282.1194; found:
m/z = 282.1189.
(E)ꢀ1,1ꢀdimethylꢀ2ꢀ(2,2,3,3,4,4,5,5,5ꢀnonafluoroꢀ1ꢀ
(Z)ꢀ1,1ꢀdimethylꢀ2ꢀ(2,2,2ꢀtrifluoroꢀ1ꢀ(4ꢀ
(trifluoromethyl)phenyl)ethylidene)hydrazine 4i. According to
general procedure 2 using 3i (43.2 mg, 200 µmol, 1.00 equiv). 4i
phenylpentylidene)hydrazine 6a. According to general procedure
3 using 3a (33 µL, 0.20 mmol, 1.0 equiv) and nonafluorobutyl
iodide (105 µL, 600 µmol, 3.00 equiv). 6a was obtained as yellow
oil (57 mg, 78%). Spectral data are in accordance with literature
reports.13 1H NMR (300 MHz, CDCl3, 300 K): δ (ppm) = 7.37 –
7.21 (m, 5H), 2.70 (s, 6H). ). 19F NMR (282 MHz, CDCl3, 300 K)
δ (ppm) = ꢀ81.2, ꢀ105.3, ꢀ120.0, ꢀ124.4.
1
was obtained as yellow oil (38.7 mg, 68%). H NMR (600 MHz,
3
3
CDCl3, 299 K): δ (ppm) = 7.64 (d, J = 8.0 Hz, 2H), 7.48 (d, J =
8.0 Hz, 2H), 2.78 (2, 6H). 13C{1H, 19F} NMR (151 MHz, CDCl3,
299 K): δ (ppm) = 136.3, 131.3, 130.4, 126.4, 125.2, 123.9, 122.1,
47.1. 19F NMR (564 MHz, CDCl3, 299 K): δ (ppm) = ꢀ63.0, ꢀ65.3.
HRMS (ESI): calcd for [C11H10F6N2H]+: m/z = 285.0826;
found: m/z = 285.0822.
(E)ꢀ1,1ꢀdimethylꢀ2ꢀ(2,2,3,3,4,4,5,5,5ꢀnonafluoroꢀ1ꢀ(4ꢀ
fluorophenyl)pentylidene)hydrazine 6b. According to general
procedure 3 using 3b (33.2 mg, 200 µmol, 1.00 equiv) and noꢀ
nafluorobutyl iodide (105 µL, 600 µmol, 3.00 equiv). 6b was
obtained as yellow oil (61.1 mg, 80%). Spectral data are in acꢀ
cordance with literature reports.13 1H NMR (300 MHz, CDCl3,
300 K): δ (ppm) = 7.24 – 7.18 (m, 2H), 7.06 – 6.90 (m, 2H), 2.68
(Z)ꢀ2ꢀ(1ꢀ(4ꢀ(tertꢀbutyl)phenyl)ꢀ2,2,2ꢀtrifluoroethylidene)ꢀ1,1ꢀ
dimethylhydrazine 4j. According to general procedure 2 using 3j
(40.9 mg, 200 µmol, 1.00 equiv). 4j was obtained as yellow oil
1
(40.5 mg, 74%). H NMR (600 MHz, CDCl3, 299 K): δ (ppm) =
3
3
7.38 (d, J = 8.2 Hz, 2H), 7.27 (d, J = 8.2 Hz, 2H), 2.73 (s, 6H),
1.33 (s, 9H). 13C{1H, 19F} NMR (151 MHz, CDCl3, 299 K): δ
(ppm) = 152.4, 130.36, 129.4, 129.1, 125.2, 122.2, 46.8, 34.9,
31.4. 19F NMR (564 MHz, CDCl3, 299 K): δ (ppm) = ꢀ65.8.
HRMS (ESI): calcd for [C14H19F3N2Na]+: m/z = 295.1398;
found: m/z = 295.1422.
(s, 6H). 19F NMR (282 MHz, CDCl3, 300 K)
= ꢀ81.2, ꢀ105.4, ꢀ111.3, ꢀ120.1, ꢀ124.5.
δ
(ppm)
(E)ꢀ2ꢀ(1ꢀ(4ꢀbromophenyl)ꢀ2,2,3,3,4,4,5,5,5ꢀ
nonafluoropentylidene)ꢀ1,1ꢀdimethylhydrazine 6c. According to
general procedure 3 using 3c (45.4 mg, 200 µmol, 1.00 equiv) and
nonafluorobutyl iodide (105 µL, 600 µmol, 3.00 equiv). 6c was
obtained as yellow oil (74.5 mg, 84%). Spectral data are in acꢀ
cordance with literature reports.13 1H NMR (300 MHz, CDCl3,
(Z)ꢀ1,1ꢀdimethylꢀ2ꢀ(2,2,2ꢀtrifluoroꢀ1ꢀ(4ꢀ
(methylthio)phenyl)ethylidene)hydrazine 4k. According to general
procedure 2 using 3k (38.9 mg, 200 µmol, 1.00 equiv). 4k was
obtained as yellow oil (41.0 mg, 78%). 1H NMR (600 MHz,
CDCl3, 299 K): δ (ppm) = 7.25 (d, J = 8.1 Hz, 2H), 7.21 (d, J =
8.1 Hz, 2H), 2.75 (s, 6H), 2.49 (s, 3H). 13C{1H, 19F} NMR
(151 MHz, CDCl3, 299 K): δ (ppm) = 140.4, 130.1, 129.2, 128.5,
3
300 K): δ (ppm) = 7.50 (d, J = 8.4 Hz, 2H), 7.19 (d, 3J = 8.4 Hz,
2H), 2.77 (s, 6H). 19F NMR (282 MHz, CDCl3, 300 K) δ (ppm)
3
3
= ꢀ81.1, ꢀ105.3, ꢀ120.1, ꢀ124.5.
(E)ꢀ4ꢀ(1ꢀ(2,2ꢀdimethylhydrazono)ꢀ2,2,3,3,4,4,5,5,5ꢀ
nonafluoropentyl)benzonitrile 6d. According to general procedure
ACS Paragon Plus Environment

Page 7 of 8
The Journal of Organic Chemistry
3 using 4ꢀcyanobenzaldehyde hydrazone 3d (34.6 mg, 200 µmol,
(t, 6H). 19F NMR (282 MHz, CDCl3, 300 K) δ (ppm) = ꢀ81.2, ꢀ
1
2
3
4
5
6
7
8
1.00 equiv) and nonafluorobutyl iodide (105 µL, 600 µmol,
3.00 equiv). 6d was obtained as yellow solid (65.1 mg, 83%).
Spectral data are in accordance with literature reports.13 1H NMR
105.3, ꢀ120.1, ꢀ124.5.
(E)ꢀ1,1ꢀdimethylꢀ2ꢀ(2,2,3,3,4,4,5,5,5ꢀnonafluoroꢀ1ꢀ(4ꢀ
methoxyphenyl)pentylidene)hydrazine 6o. According to general
procedure 3 using 3o (35.7 mg, 200 µmol, 1.00 equiv) and noꢀ
nafluorobutyl iodide (105 µL, 600 µmol, 3.00 equiv). 6o was
obtained as yellow oil (56.0 mg, 77%). Spectral data are in acꢀ
cordance with literature reports.13 1H NMR (600 MHz, CDCl3,
300 K): δ (ppm) = 7.23 (d, 3J = 8.7 Hz, 2H), 6.93 – 6.82 (m, 2H),
3.83 (s, 3H), 2.74 (s, 6H). 19F NMR (564 MHz, CDCl3, 300 K) δ
(ppm) = ꢀ81.19, ꢀ105.63, ꢀ120.07, ꢀ124.44.
3
(300 MHz, CDCl3, 300 K): δ (ppm) = 7.66 (d, J = 8.3 Hz, 2H),
7.44 (d, 3J = 8.3 Hz, 2H), 2.80 (s, 6H). 19F NMR (282 MHz,
CDCl3, 300 K) δ (ppm) = ꢀ81.2, ꢀ104.8, ꢀ120.2, ꢀ124.6.
Methyl
(E)ꢀ4ꢀ(1ꢀ(2,2ꢀdimethylhydrazono)ꢀ2,2,3,3,4,4,5,5,5ꢀ
nonafluoropentyl)benzoate 6f. According to general procedure 3
using 3f (41.3 mg, 200 µmol, 1.00 equiv) and nonafluorobutyl
iodide (105 µL, 600 µmol, 3.00 equiv). 6f was obtained as yellow
solid (67.6 mg, 79%). 1H NMR (600 MHz, CDCl3, 300 K): δ
(ppm) = 8.07 – 7.97 (m, 2H), 7.42 – 7.37 (m, 2H), 3.93 (s, 3H),
2.77 (s, 6H). 13C{1H, 19F} NMR (151 MHz, CDCl3) δ (ppm) =
166.6, 130.6, 129.2, 126.1, 117.8, 114.0, 111.5, 109.2, 52.4, 46.8.
19F NMR (564 MHz, CDCl3, 300 K) δ (ppm) = ꢀ81.2, ꢀ105.0, ꢀ
120.1, ꢀ124.5. HRMS (ESI): calcd for [C15H13F9N2O2Na]+: m/z
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
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
56
57
58
59
60
(E)ꢀ1,1ꢀdimethylꢀ2ꢀ(2,2,3,3,4,4,5,5,5ꢀnonafluoroꢀ1ꢀ
(naphthalenꢀ2ꢀyl)pentylidene)hydrazine 6p. According to general
procedure 3 using 3p (39.7 mg, 200 µmol, 1.00 equiv) and noꢀ
nafluorobutyl iodide (105 µL, 600 µmol, 3.00 equiv). 6p was
obtained as yellow oil (38.4 mg, 46%). 1H NMR (600 MHz,
CDCl3, 300 K): δ (ppm) = 7.88 – 7.84 (m, 2H), 7.84 – 7.82 (m,
1H), 7.81 – 7.80 (m, 1H), 7.57 – 7.49 (m, 2H), 7.43 (m, 1H), 2.77
(s, 6H). 13C{1H, 19F} NMR (151 MHz, CDCl3) δ (ppm) = 133.1,
132.4, 129.8, 129.7, 128.3, 128.1, 127.7, 127.5, 127.3, 127.0,
126.6, 117.7, 114.0, 111.4, 109.1, 46.6. 19F NMR (564 MHz,
CDCl3, 300 K) δ (ppm) = ꢀ81.1, ꢀ105.0, ꢀ119.9, ꢀ124.4. HRMS
(ESI): calcd for [C17H13F9N2H]+: m/z = 417.1013; found: m/z =
417.0999, calcd for [C17H13F9N2Na]+: m/z = 439.0833; found:
m/z = 439.0822.
=
447.0731; found: m/z
=
447.0742, calcd for
[(C15H13F9N2O2)Na]+: m/z = 871.1564; found: m/z = 871.1562.
Mp 26ꢀ27 °C.
(E)ꢀ4ꢀ(1ꢀ(2,2ꢀdimethylhydrazono)ꢀ2,2,3,3,4,4,5,5,5ꢀ
nonafluoropentyl)ꢀN,Nꢀdimethylaniline 6h. According to general
procedure 3 using 3h (38.3 mg, 200 µmol, 1.00 equiv) and noꢀ
nafluorobutyl iodide (105 µL, 600 µmol, 3.00 equiv). 6h was
obtained as yellow solid (38.2 mg, 47%). 1H NMR (300 MHz,
3
3
CDCl3, 300 K): δ (ppm) = 7.16 (d, J = 8.9 Hz, 2H), 6.66 (d, J =
8.9 Hz, 2H), 2.99 (s, 6H), 2.73 (s, 6H). 13C{1H, 19F} NMR
(151 MHz, CDCl3) δ (ppm) = 19F NMR (564 MHz, CDCl3,
300 K) δ (ppm) = ꢀ81.2, ꢀ105.8, ꢀ120.0, ꢀ124.4. HRMS (ESI):
calcd for [C15H16F9N3H]+: m/z = 410.1279; found: m/z =
410.1276, calcd for [C15H16F9N3Na]+: m/z = 432.1098; found:
m/z = 432.1095.
1,4ꢀBis((E)ꢀ1ꢀ(2,2ꢀdimethylhydrazono)ꢀ2,2,3,3,4,4,5,5,5ꢀ
nonafluoropentyl)benzene 6q. According to general procedure 3
using 3q (43.7 mg, 200 µmol, 1.00 equiv) and nonafluorobutyl
iodide (105 µL, 600 µmol, 3.00 equiv). 6q was obtained as yellow
solid (48.0 mg, 37%). 1H NMR (600 MHz, CDCl3, 300 K): δ
(ppm) = 7.31 (s, 4H), 2.76 (s, 12H).13C{1H, 19F} NMR (151 MHz,
CDCl3) δ (ppm) = 133.2, 129.8, 126.7, 117.6, 113.8, 111.3, 109.0,
46.5.19F NMR (564 MHz, CDCl3, 300 K) δ (ppm) = ꢀ81.2, ꢀ105.3,
ꢀ120.1, ꢀ124.5. HRMS (ESI): calcd for [C20H16F18N4Na]+: m/z
= 677.0985; found: m/z = 677.0989. Mp: 63ꢀ64 °C.
(E)ꢀ2ꢀ(1ꢀ(4ꢀ(tertꢀbutyl)phenyl)ꢀ2,2,3,3,4,4,5,5,5ꢀ
nonafluoropentylidene)ꢀ1,1ꢀdimethylhydrazine 6j. According to
general procedure 3 using 3j (40.9 mg, 200 µmol, 1.00 equiv) and
nonafluorobutyl iodide (105 µL, 600 µmol, 3.00 equiv). 6j was
obtained as yellow solid (61.6 mg, 73%). 1H NMR (300 MHz,
CDCl3, 300 K): δ (ppm) = 7.41 – 7.31 (m, 2H), 7.28 – 7.19 (m,
2H), 2.73 (s, 6H), 1.33 (s, 6H). 13C{1H, 19F} NMR (151 MHz,
CDCl3) δ (ppm) = 152.2, 129.8, 129.1, 129.0, 124.8, 117.7, 113.9,
111.4, 109.1, 46.4, 42.7, 34.7, 31.2. 19F NMR (282 MHz, CDCl3,
300 K) δ (ppm) = ꢀ81.2, ꢀ105.3, ꢀ120.0, ꢀ124.4. HRMS (ESI):
calcd for [C17H19F9N2Na]+: m/z = 445.1302; found: m/z =
445.1307. Mp: 25ꢀ27 °C.
(E)ꢀ1,1ꢀdimethylꢀ2ꢀ(2,2,3,3,4,4,5,5,5ꢀnonafluoroꢀ1ꢀ(oꢀ
tolyl)pentylidene)hydrazine 6r. According to general procedure 3
using 3r (32.5 mg, 200 µmol, 1.00 equiv) and nonafluorobutyl
iodide (105 µL, 600 µmol, 3.00 equiv). 6r was obtained as yellow
1
oil (32.8 mg, 37%). H NMR (600 MHz, CDCl3, 300 K): δ (ppm)
3
4
3
= 7.28 (td, J = 7.5 Hz, J = 1.5 Hz, 1H), 7.25 (d, J = 7.5 Hz,
1H), 7.22 – 7.17 (m, 1H), 7.19 – 7.13 (m, 1H), 2.72 (s, 6H), 2.24
(s, 3H). 13C{1H, 19F} NMR (151 MHz, CDCl3) δ (ppm) = 138.9,
131.9, 130.5, 129.5, 129.3, 127.8, 125.0, 117.7, 114.3, 111.5,
109.1, 45.7, 19.8. 19F NMR (564 MHz, CDCl3, 300 K) δ (ppm)
(E)ꢀ2ꢀ(1ꢀ(benzo[d][1,3]dioxolꢀ5ꢀyl)ꢀ2,2,3,3,4,4,5,5,5ꢀ
nonafluoropentylidene)ꢀ1,1ꢀdimethylhydrazine 6l. According to
general procedure 3 using 3l (38.4 mg, 200 µmol, 1.00 equiv) and
nonafluorobutyl iodide (105 µL, 600 µmol, 3.00 equiv). 6l was
obtained as yellow oil (52.6 mg, 73%). 1H NMR (600 MHz,
CDCl3, 300 K): δ (ppm) = 6.85 – 6.71 (m, 3H), 6.00 (s, 2H), 2.78
(s, 6H). 13C{1H, 19F} NMR (151 MHz, CDCl3) δ (ppm) = 148.3,
147.4, 128.0, 125.5, 124.55, 117.8, 114.0, 111.6, 110.6, 109.2,
108.0, 101.5, 46.5. 19F NMR (564 MHz, CDCl3, 300 K) δ (ppm)
=
ꢀ81.2, ꢀ104.8, ꢀ119.7, ꢀ123.9. HRMS (ESI): calcd for
[C14H13F9N2H]+: m/z = 381.1013; found: m/z = 381.1009, calcd
for [C14H13F9N2Na]+: m/z = 403.0833; found: m/z = 403.0824.
(E)ꢀ1,1ꢀdimethylꢀ2ꢀ(2,2,3,3,4,4,5,5,6,6,7,7,7ꢀtridecafluoroꢀ1ꢀ
phenylheptylidene)hydrazine 6s. According to general procedure 3
using 3a (33 µL, 0.20 mmol, 1.0 equiv) and perfluorohexyl iodide
(130 µL, 600 µmol, 3.00 equiv). 6s was obtained as orange oil
1
(81.4 mg, 87%). H NMR (600 MHz, CDCl3, 300 K): δ (ppm) =
7.39 – 7.32 (m, 3H), 7.34 – 7.29 (m, 2H), 2.74 (s, 6H). 13C{1H,
19F} NMR (151 MHz, CDCl3) δ (ppm) = 132.5, 130.5, 129.2,
128.5, 128.1, 118.4, 116.5, 114.1, 111.5, 110.6, 108.9, 108.6,
46.6. 19F NMR (564 MHz, CDCl3, 300 K) δ (ppm) = ꢀ80.9, ꢀ
105.2, ꢀ119.3, ꢀ120.5, ꢀ122.8, ꢀ126.1. HRMS (ESI): calcd for
[C15H11F13N2Na]+: m/z = 489.0612; found: m/z = 489.0619.
=
ꢀ81.2, ꢀ105.4, ꢀ120.0, ꢀ124.4. HRMS (ESI): calcd for
[C14H11F9N2O2H]+: m/z = 411.0755; found: m/z = 411.0627,
calcd for [C14H11F9N2O2Na]+: m/z = 433.0575; found: m/z =
433.0566.
(E)ꢀ2ꢀ(1ꢀ(4ꢀchlorophenyl)ꢀ2,2,3,3,4,4,5,5,5ꢀ
nonafluoropentylidene)ꢀ1,1ꢀdimethylhydrazine 6n. According to
general procedure 3 using 3n (36.5 mg, 200 µmol, 1.00 equiv)
and nonafluorobutyl iodide (105 µL, 600 µmol, 3.00 equiv). 6n
was obtained as yellow oil (63.9 mg, 80%). Spectral data are in
accordance with literature reports.13 1H NMR (300 MHz, CDCl3,
300 K): δ (ppm) = 7.40 – 7.29 (m, 2H), 7.28 – 7.28 (m, 2H), 2.77
(E)ꢀ2ꢀ(2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9,9ꢀheptadecafluoroꢀ1ꢀ
phenylnonylidene)ꢀ1,1ꢀdimethylhydrazine 6t. According to genꢀ
eral procedure 3 using 3a (33 µL, 0.20 mmol, 1.0 equiv) and
perfluorooctyl iodide (160 µL, 600 µmol, 3.00 equiv). 6t was
obtained as orange oil (97.1 mg, 86%). 1H NMR (600 MHz,
CDCl3, 300 K): δ (ppm) = 7.39 – 7.33 (m, 3H), 7.33 – 7.28 (m,
ACS Paragon Plus Environment

The Journal of Organic Chemistry
Page 8 of 8
2H), 2.74 (s, 6H). 13C{1H, 19F} NMR (151 MHz, CDCl3) δ (ppm)
ACKNOWLEDGMENT
1
2
3
4
5
6
7
8
= 132.3, 130.3, 129.0, 128.3, 127.9, 117.1, 113.9, 111.9, 111.3,
111.0, 110.8, 110.2, 108.4, 46.4. 19F NMR (564 MHz, CDCl3,
300 K) δ (ppm) = ꢀ80.9, ꢀ105.2, ꢀ119.3, ꢀ120.4, ꢀ121.9, ꢀ122.8, ꢀ
126.2. HRMS (ESI): calcd for [C17H11F17N2H]+: m/z =
567.0729; found: m/z = 567.0739, calcd for [C17H11F17N2Na]+:
m/z = 589.0548; found: m/z = 589.0567.
We thank the European Research Council (ERC Advanced Grant
agreement No. 692640) for financial support.
REFERENCES
(1) Verma, G.; Marella, A.; Shaquiquzzaman, M.; Akhtar, M.; Ali, M.
R.; Alam, M. M. J. Pharm. Bioallied Sci. 2014, 6, 69 – 80.
(2) Lazny, R.; Nodzewska, A. Chem. Rev. 2010, 110, 1386 – 1434.
(3) Yamazaki, T.; Taguchi, T.; Ojima, I. in Fluorine in Medicinal
Chemistry and Chemical Biology, Ojima, I., Ed.; WileyꢀBlackwell: Chichꢀ
ester, 2009.
(E)ꢀ2ꢀ(2,2,3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,11,11,11ꢀ
henicosafluoroꢀ1ꢀphenylundecylidene)ꢀ1,1ꢀdimethylhydrazine 6u.
According to general procedure 3 using 3a (33 µL, 0.20 mmol,
1.0 equiv) and perfluorodecyl iodide (366 mg, 600 µmol,
9
1
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
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
56
57
58
59
60
3.00 equiv). 6u was obtained as purple solid (119 mg, 89%). H
NMR (600 MHz, CDCl3, 300 K): δ (ppm) = 7.39 – 7.32 (m, 3H),
7.33 – 7.28 (m, 2H), 2.74 (s, 6H). 13C{1H, 19F} NMR (151 MHz,
CDCl3) δ (ppm) = 132.3, 130.3, 128.9, 128.4, 127.9, 117.1, 113.9,
111.9, 111.3, 111.0, 110.9, 110.8, 110.7, 110.2, 108.3, 46.4. 19F
NMR (564 MHz, CDCl3, 300 K) δ (ppm) = ꢀ80.9, ꢀ105.3, ꢀ119.3,
ꢀ120.3, ꢀ121.8, ꢀ122.8, ꢀ126.2. HRMS (ESI): calcd for
[C19H11F21N2H]+: m/z = 667.0665; found: m/z = 667.0679,
calcd for [C19H11F21N2Na]+: m/z = 689.0485; found: m/z =
689.0501. Mp: 37ꢀ39 °C.
(4) (a) Purser, S.; Moore, P. R.; Swallow, S.; Gouverneur, V. Chem.
Soc. Rev. 2008, 37, 320 – 330. (b) Müller, K.; Faeh, C.; Diederich, F.
Science 2007, 317, 1881 – 1886. (c) Shimizu, M.; Hiyama, T. Angew.
Chem., Int. Ed. 2005, 44, 214 – 231.
(5) Jeschke, P. ChemBioChem 2004, 5, 570 – 589.
(6) (a) Hiyama, T. in Organofluorine Compounds: Chemistry and Apꢀ
plication, Springer: Berlin, 2000. (b) Hird, M. Chem. Soc. Rev. 2007, 36,
2070–2095.
(7) Liu, X.; Xu, C.; Wang, M.; Liu, Q. Chem. Rev. 2015, 115, 683 –
730.
(8) (a) Studer, A. Angew. Chem., Int. Ed. 2012, 51, 8950 – 8958. (b)
Zhang, C. Adv. Synth. Catal. 2014, 356, 2895 – 2906. (c) BarataꢀVallejo,
S.; Lantaño, B.; Postigo, A. Chem. Eur. J. 2014, 20, 16806 – 16829.
(9) (a) Liang, T.; Neumann C. N.; Ritter, T. Angew. Chem., Int. Ed.
2013, 52, 8214–8264. (b) Merino, E.; Nevado, C. Chem. Soc. Rev. 2014,
43, 6598–6608. (c) Egami, H.; Sodeoka, M. Angew. Chem., Int. Ed. 2014,
53, 8294–8308.
Ethyl
(E)ꢀ3ꢀ(2,2ꢀdimethylhydrazono)ꢀ2,2ꢀdifluoroꢀ3ꢀ
phenylpropanoate 6v. According to general procedure 3 using 3a
(3 µL, 0.20 mmol, 1.0 equiv), ethyl iododifluoroacetate (88 µL,
0.60 mmol, 3.0 equiv) and hexabutylditin (5 µL, 0.02 mmol,
0.1 equiv). The compound was purified using a Reveleris Amino
4 g column. 6v was obtained as a yellow oil (44.3 mg, 82%).
1H NMR (600 MHz, CDCl3, 300 K): δ (ppm) = 7.43 – 7.33 (m,
(10) Charpentier, J.; Früh, N.; Togni, A. Chem. Rev. 2015, 115, 650 −
682.
3
3
5H), 4.38 (q, J = 7.1 Hz, 2H), 2.68 (s, 6H), 1.39 (t, J = 7.1 Hz,
3H). 13C{1H, 19F} NMR (151 MHz, CDCl3) δ (ppm) = 164.4,
134.0, 131.9, 129.9, 129.1, 128.1, 115.3, 62.5, 46.6, 14.2. 19F
NMR (564 MHz, CDCl3, 300 K) δ (ppm) = ꢀ100.1. HRMS (ESI):
calcd for [C13H16F2N2O2H]+: m/z = 271.1253; found: m/z =
271.1264.
(11) (a) Pair, E.; Monteiro, N.; Bouyssi, D.; Baudoin, O. Angew.
Chem., Int. Ed., 2013, 52, 5346 – 5349. (b) Prieto, A.; Jeamet, E.; Monꢀ
teiro, N.; Bouyssi, D.; Baudoin, O. Org. Lett. 2014, 16, 4770 – 4773. (c)
Prieto, A.; Landart, M.; Baudoin, O.; Monteiro, N.; Bouyssi D. Adv.
Synth. Catal. 2015, 357, 2939 – 2943.
(12) Xie, J.; Zhang, T.; Chen, F.; Mehrkens, N.; Rominger, F.; Ruꢀ
dolph, M.; Hashmi, A. S. K. Angew. Chem., Int. Ed. 2016, 55, 2934 –
2938.
(13) Xie, J., Li, J.; Wurm, T.; Weingand, V.; Sung, H.ꢀL.; Rominger,
F.; Rudolph, M.; Hashmi, A. S. K. Org. Chem. Front. 2016, 3, 841 – 845.
(14) (a) Studer, A.; Curran, D. P. Nat. Chem. 2014, 6, 765 – 773. (b)
Studer, A.; Curran, D. P. Angew. Chem., Int. Ed. 2016, 55, 58 – 102.
(15) Zhang, B.; MückꢀLichtenfeld, C.; Daniliuc, C. G.; Studer, A.
Angew. Chem., Int. Ed. 2013, 52, 10792 – 10795.
(16) Leifert, D.; Artiukhin, D. G.; Neugebauer, J.; Galstyan, A.;
Strassert, C. A.; Studer, A. Chem. Commun. 2016, 52, 5997 – 6000.
(17) (a) Curran, D. P.; Chen, M.ꢀH.; Kim, D. J. Am. Chem. Soc. 1989,
111, 6265 –6276. (b) Curran, D. P.; Chang, C.ꢀT. Tetrahedron Lett. 1990,
31, 933 –936.
ASSOCIATED CONTENT
Supporting Information
The Supporting Information is available free of charge on the
ACS Publications website.
NMR spectra (PDF)
AUTHOR INFORMATION
Corresponding Author
(18) Li, Y.; Studer, A. Angew. Chem. Int. Ed. 2012, 51, 8221 – 8224.
.
studer@uniꢀmuenster.de
Notes
The authors declare no competing financial interests.
TOC graphic
ACS Paragon Plus Environment