Chemoselectivity Switching in the Rhodium-Catalyzed Reactions of 4-Substituted-1-sulfonyl-1,2,3-triazoles with Allenols: Noticeable Differences between 4-Acyl- and 4-Aryl-Triazoles

Article abstract of DOI:10.1002/adsc.201801424

Tunable chemoselectivity (O- versus C-attack) in the rhodium-catalyzed reactions of allenols with 4-substituted-1-sulfonyl-1,2,3-triazoles has been achieved through the replacement of the 4-aryl substituent by a 4-acetyl moiety. (Figure presented.).

Full text of DOI:10.1002/adsc.201801424

Title: Chemoselectivity Switching in the Rhodium-Catalyzed Reactions
of 4-Substituted-1-sulfonyl-1,2,3-triazoles with Allenols:
Noticeable Differences between 4-Acyl- and 4-Aryl-Triazoles
Authors: Pedro Almendros, Benito Alcaide, Israel Fernandez, Teresa
Martínez del Campo, Guillermo Palop, Mireia Toledano-
Pinedo, and Patricia Delgado
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To be cited as: Adv. Synth. Catal. 10.1002/adsc.201801424
Link to VoR: http://dx.doi.org/10.1002/adsc.201801424

10.1002/adsc.201801424
Advanced Synthesis & Catalysis
UPDATES
DOI: 10.1002/adsc.200((will be filled in by the editorial sttaff))
Chemoselectivity Switching in the Rhodium-Catalyzed
Reactions of 4-Substituted-1-sulfonyl-1,2,3-triazoles with
Allenols: Noticeable Differences between 4-Acyl- and 4-Aryl-
Triazoles
Benito Alcaide,a* Pedro Almendros,b* Israel Fernández,c Teresa Martínez del Campo,a
Guillermo Palop,a Mireia Toledano-Pinedo,a and Patricia Delgado-Martínezd,§
a
Grupo de Lactamas y Heterociclos Bioactivos, Departamento de Química Orgánica I, Unidad Asociada al CSIC,
Facultad de Química, Universidad Complutense de Madrid, 28040 Madrid, Spain, E-mail: alcaideb@quim.ucm.es
Instituto de Química Orgánica General, Consejo Superior de Investigaciones Científicas, IQOG-CSIC, Juan de la
b
Cierva 3, 28006 Madrid, Spain, E-mail: palmendros@iqog.csic.es
Departamento de Química Orgánica I and Centro de Innovación en Química Avanzada (ORFEO-CINQA), Facultad de
c
Química, Universidad Complutense de Madrid, 28040 Madrid, Spain
CAI Difracción de Rayos X, Facultad de Química, Universidad Complutense de Madrid, 28040 Madrid, Spain
d
Received: ((will be filled in by the editorial staff))
Supporting information for this article is available on the WWW under http://dx.doi.org/10.1002/adsc.200######.((Please
delete if not appropriate))
attack/reorganization sequence between allenols and
Abstract. Tunable chemoselectivity (O- versus C-attack) in
the rhodium-catalyzed reactions of allenols with 4- 4-acyl-1-tosyl-1,2,3-triazoles leading to 3-methylene-
substituted-1-sulfonyl-1,2,3-triazoles has been achieved
through the replacement of the 4-aryl substituent by a 4-
acetyl moiety.
5,6-dioxo-hept-1-enyl-4-amine derivatives (Scheme
1d).
Keywords: allenes; heterocycles; homogeneous catalysis;
ketones; rhodium
1-Sulfonyl-1,2,3-triazole chemistry has merged as an
excellent approach for the functionalization of
unsaturated moieties and the construction of
heterocyclic frameworks.[1] This strategy has been
built through the use of 4-aryl-1-sulfonyl-1,2,3-
triazoles as the source of α-imino metal-carbenes,
which may be viewed as donor/acceptor carbenoids.
At the end of 2017, Miura and Murakami unveiled the
chemistry of acceptor/acceptor carbenoids, which
were generated from 4-acyl-1-mesyl-1,2,3-triazoles,
for the functionalization of aromatic C(sp2)–H bonds
(Scheme 1a).[2] Markedly contrasting results were
obtained in comparison with donor/acceptor
carbenoids.[3] On the other hand, dramatic growth in
the synthetic utility of allenes has been noticed in the
last decade.[4] Recently, Miura and Murakami have
described the metal-catalyzed reaction of 4-aryl-1-
tosyl-1,2,3-triazoles with simple allenes to form
pyrroles or α,β,γ,δ-unsaturated imines (Scheme 1b),[5]
while we reported the transannulation reaction of 4-
aryl-1-tosyl-1,2,3-triazoles with allenols to give 2-
pyrrolines (Scheme 1c).[6] Based on these results, we
believed that allenols might also act as an O-
containing nucleophiles able to trap acceptor/acceptor
carbenoids. Herein, we describe an unprecedented O-
Scheme 1. Mode of reaction between 1-sulfonyl-1,2,3-
triazoles and allenes: previous work and the present study.
Allenol 1a was selected as model substrate. Initial
experiments were performed through the reaction of
1a
with
the
previously described
1-[1-
(methylsulfonyl)-1H-1,2,3-triazol-4-yl]ethan-1-one,
but complex reaction mixtures were obtained. Nicely,
1-(1-tosyl-1H-1,2,3-triazol-4-yl)ethan-1-one 2, which
was easily prepared following the reported procedure
for its methylsulfonyl counterpart,[2] was shown to be
a promising reaction partner. The use of Rh2(Oct)4 as
1
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10.1002/adsc.201801424
Advanced Synthesis & Catalysis
catalyst (1 mol%) and chloroform as solvent allowed
the coupling between 1a and 2 to progress at 65 oC and
gave a reasonable 58% yield of product 3a (Table 1,
entry 3). The efficiency of the process could not be
improved by moving to different metallic salts,
solvents or reaction conditions. Adduct 3a is a
polydecorated molecule[7] bearing a 1,2-diketone
functionality, a sulfonamide group, and a 1,3-diene
moiety, which was obtained as single Z isomer at the
newly formed double bond. Noteworthy, replacing an
aryl group by an acetyl group in the metal-catalyzed
reactions of 4-substituted-1-sulfonyl-1,2,3-triazoles
obtained, without altering the total stereoselectivity.
The single crystal XRD structure of adduct 3a
unambiguously confirmed its polyfunctional nature
and stereochemistry (Figure 1).[9] Notably, the
methylidene moiety survived under the reactions
conditions and no isomerization towards the fully
conjugated system occurred. Next, the scope of the
reaction with respect to the 4-acyl-triazole reagent was
explored
using
1-(1-tosyl-1H-1,2,3-triazol-4-
yl)propan-1-one 2-Et and phenyl(1-tosyl-1H-1,2,3-
triazol-4-yl)methanone 2-Ph. Interestingly, triazole
derivative 2-Et was as rewarding as triazole 2. As
depicted in Scheme 2, the reactions of 2-Et with
allenols 1b and 1c worked well for the obtention of
molecules of type 3. Unfortunately, the Rh-catalyzed
treatment of triazole 2-Ph with allenols 1b and 1c
resulted in complicated reaction mixtures and was
non-productive for the preparation of adducts 3.
with allenols
1
dramatically provokes
a
chemoselectivity switch (O- versus C-attack).[8]
Table 1. Optimization of reaction conditions for the metal-
catalyzed coupling of allenol 1a with acyl-triazole 2.[a], [b], [c]
Entry
Catalyst
Solvent
T
Time
(h)
Yield
(%)[d]
(oC)
1
2
Rh2(OAc)
Rh2(Esp)2
Rh2(Oct)4
Cu(OTf)2
AgNTf2
CHCl3
CHCl3
CHCl3
toluene
toluene
CHCl3
CHCl3
CHCl3
1,2-DCE
toluene
65
65
65
70
70
20
40
65
70
70
2
2
3a (17)
3a (30)
3a (58)
–
3
2
4
3
5
4
–
6
Rh2(Oct)4
Rh2(Oct)4
Rh2(Oct)4
Rh2(Oct)4
Rh2(Oct)4
24
6
3a (14)
3a (35)
3a (49)
3a (45)
3a (18)
7
8
3
9
2
10
8
[a]
[b]
Reactions were carried out using 1a (0.2 mmol), 2 (0.4
mmol), and the catalyst (0.002 mmol) in the corresponding
solvent (0.15 M).
OAc
=
acetate; Esp
=
(α,α,α′,α′-tetramethyl-1,3-
benzenedipropionate); Oct = octanoate; 1,2-DCE = 1,2-
dichloroethane.
1,2-DCE = 1,2-dichloroethane.
Yield of pure, isolated product with correct analytical and
spectral data.
[c]
[d]
Having in hand the optimized conditions, we then
investigated the scope and generality of the
transformation by modifying the substitution on the
allenol substrate 1. The observed results are depicted
in Scheme 2. Almost all reactions progressed smoothly
to provide the desired products 3a–h in reasonable
yields. Various substituents on the aromatic ring (R1)
of different electronic demand such as activating
(methyl and methoxy) and weakly deactivating
(chlorine) were well accommodated. Different
substitution patterns were also tolerated, because when
a substituent was placed either at the ortho, meta, and
para positions of the phenyl ring, the corresponding
products were formed in fair yields as single Z isomers.
When the methyl group (R2) of 1a was replaced by an
aryl group such as phenyl and 4-BrC6H4, the required
polyfunctionalyzed adducts 3f–h were efficiently
Scheme 2. Synthesis of polydecorated compounds 3a–j.
2
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10.1002/adsc.201801424
Advanced Synthesis & Catalysis
Figure 1. ORTEP drawing of (Z)-4-methyl-N-(2-methyl-3-
methylene-5,6-dioxo-1-phenylhept-1-en-4-
yl)benzenesulfonamide 3a. Thermal ellipsoids shown at
50% probability.
A possible pathway for the rhodium-catalysed
generation of polyfunctional compounds 3 is outlined
in Scheme 3. Initially, the formation of an α-imino
Rh(II)-carbenoid INT-2 may be involved. INT-2
should be formed by reaction of the Rh2(Oct)4 catalyst
with 4-acetyl-1-tosyl-1,2,3-triazole 2 through its α-
imino tautomer INT-1, with concurrent dinitrogen
release, according to the general reaction mechanism
proposed by Miura and Murakami.[2] Next,
nucleophilic addition of the hydroxyl functionality of
allenes 1 to rhodacarbenoid INT-2 followed by
deprotonation could lead to species INT-3. This path
must be driven by the highly electrophilic character of
the acceptor/acceptor rhodacarbenoid INT-2.[10]
Species INT-3 evolves into an allenyl vinyl ether
intermediate after regeneration of the rhodium catalyst
and concurrent protonation (Scheme 3). This allenyl
vinyl ether intermediate may then undergo an allenic
Claisen rearrangement to form 3-methylene-5,6-
dioxo-hept-1-enyl-4-amine derivatives 3 (Scheme 3),
which resembles that proposed by Miura and
Murakami.[7b]
Scheme 3. Mechanistic explanation for the Rh(II)-catalyzed
synthesis of polyfunctional compounds 3.
Density Functional Theory (DFT) calculations at
the
dispersion-corrected
PCM(CHCl3)-B3LYP-
D3/def2-SVP level were carried out to gain more
insight into mechanism involved in the
transformation.[11] To this end, the reaction between
the experimentally used substrates allenol 1a and the
Rh(II)-carbene INT-2 was explored.
As shown in Figure 2, which gathers the
corresponding free energies (computed at 298 K), the
process begins with the formation of complex INT-4,
where both reagents are linked by a hydrogen bond
established between the OH group of the allenol and
the nitrogen atom of the Rh(II)-carbenoid. INT-4 is
then readily transformed into INT-5 by means of the
insertion of the OH into the carbene carbon atom. This
process is essentially barrierless, which is not
surprising considering the highly exergonicity
computed for this reaction step (∆GR = –45.9 kcal/mol).
Indeed, relaxed scans from INT-4 at different
Ccarbene···OH confirms the barrierless nature of this
insertion reaction (see Figure 3). Release of the weakly
bonded dirhodium catalyst in INT-5 leads to
zwitterion INT-6 in an endergonic transformation
(∆GR = 13.4 kcal/mol), which is compatible with the
temperature required experimentally.[12] As a result of
the abstraction of a proton from the OH-moeity by the
imine,
(Z)-allenyl
vinyl
ether
INT-6 is
stereoselectively formed. Finally, INT-6 can be
directly converted into the observed dioxo-hept-1-
enyl-4-amine 3a through the transition state TS in a
highly exergonic transformation (∆GR = –40.6
kcal/mol) and with a relatively low activation barrier
of 15.2 kcal/mol. As depicted in Figure 2, this saddle-
point is associated with the simultaneous C–O bond
rupture and formation of the new C–C bond leading to
the observed Z-dioxo-amine in a Claisen type [3,3]-
sigmatropic
rearrangement.
Therefore,
our
calculations are fully consistent with our initial
3
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10.1002/adsc.201801424
Advanced Synthesis & Catalysis
Experimental Section
proposal described above (Scheme 3) based on the
proposal by Miura and Murakami.[7b]
1
General methods: H NMR and 13C NMR spectra were
recorded on a Bruker Avance-300 or Bruker Avance AMX-
700 spectrometers. NMR spectra were recorded in CDCl3 or
C6D6, except otherwise stated. Chemical shifts are given in
ppm relative to TMS (1H, 0.0 ppm), CDCl3 (13C, 76.9 ppm)
and C6D6 (13C, 128.4 ppm). Low and high resolution mass
spectra were taken on an AGILENT 6520 Accurate-Mass
QTOF LC/MS spectrometer using the electrospray mode
(ES) unless otherwise stated. IR spectra were recorded on a
Bruker Tensor 27 spectrometer. X-Ray crystallographic
data were collected on a Bruker Smart CCD difractomer
using graphite-monochromated Mo-K radiation ( =
0.71073 Å) operating at 50 Kv and 35 mA with an exposure
of 30.18 s in . All commercially available compounds
were used without further purification.
General procedure for the rhodium-catalyzed reactions
of allenols 1a–h with acyl-triazole 2. Synthesis of 3-
methylene-5,6-dioxo-hept-1-enyl-4-amine
derivatives
Figure 2. Computed profile for the transformation
involving allenol 1a and Rh(II)-carbene INT-2. Bond
lengths and relative free energies (∆G298, computed at 298
K) are given in angstroms and kcal/mol, respectively. All
data have been computed at the PCM(CHCl3)-B3LYP-
D3/def2-SVP level.
3a–h.
Rh2(Oct)4 (2.3 mg, 0.003 mmol) and acyl-triazole 2 (159 mg,
0.6 mmol) were added to a stirred solution of the appropriate
allenol 1 (0.3 mmol) in chloroform (2.0 mL). The reaction
o
mixture was stirred at 65 C for 2 h, allowed to cool to rt,
and concentrated under reduced pressure. Chromatography
of the residue eluting with hexanes/ethyl acetate (8:1) gave
analytically pure compounds 3. Spectroscopic and
analytical data for compounds 3 follow.[13]
(Z)-4-Methyl-N-(2-methyl-3-methylene-5,6-dioxo-1-
phenylhept-1-en-4-yl)benzenesulfonamide 3a. From 68
mg (0.427 mmol) of allenol 1a, and after chromatography
of the residue, gave compound 3a (78 mg, 58%) as a green
solid; mp 103–105 ºC; 1H-NMR (300 MHz, C6D6, 25 oC) :
7.65 (d, 2H, J = 8.3 Hz, ArH), 7.23 (d, 2H, J = 7.3 Hz, ArH),
7.09 (t, 2H, J = 10.3 Hz, ArH), 6.98 (t, 1H, J = 7.3 Hz, ArH),
6.64 (d, 2H, J = 8.0 Hz, ArH), 6.10 (s, 1H, =CH), 5.72 (d,
1H, J = 9.8 Hz, CH-NH), 5.59 (d, 1H, J = 9.8 Hz, CH-NH),
5.03 (d, 1H, J = 1.2 Hz, CHH), 4.91 (s, 1H, CHH), 1.81 (d,
3H, J = 1.4 Hz, Me), 1.78 (s, 3H, Me), 1.64 (s, 3H, Ar); 13C-
NMR (75 MHz, C6D6, 25 ºC) : 195.5 (C=O), 194.3 (C=O),
143.4, 143.2, 137.6, 137.1, 135.8, 129.7 (Ar, 2CH), 129.6
(=CH), 128.9 (Ar, 2CH), 128.5 (Ar, 2CH), 127,7 (Ar, 2CH),
127.3 (Ar, CH), 119.1 (=CH2), 58.08 (CH-NH), 26.08 (Me),
23.4 (Me), 21.1 (Me); IR (C6H6, cm–1):  3276, 1718, 1596,
1159; HRMS (ES): calcd for C22H24NO4S [M + H]+:
398.14206; found: 398.14165.
Figure 3. Relaxed scans modifying the key C···O distance
for the INT-4INT-5 transformation. All data have been
computed at the PCM(CHCl3)-B3LYP-D3/def2-SVP level.
In conclusion, we have developed a divergent
outcome transformation of the rhodium-catalyzed
reactions of allenols with 4-substituted-1-sulfonyl-
1,2,3-triazoles, which has been accomplished through
the replacement of the 4-aryl substituent by a 4-acetyl
(Z)-4-Methyl-N-(2-methyl-3-methylene-5,6-dioxo-1-(p-
tolyl)hept-1-en-4-yl)benzenesulfonamide 3b. From 50 mg
(0.315 mmol) of allenol 1b, and after chromatography of the
residue, gave compound 3b (49 mg, 38%) as a yellow oil;
1H-NMR (300 MHz, C6D6, 25 oC) : 7.67 (d, 2H, J = 8.3 Hz,
ArH), 7.20 (s, 2H, ArH), 6.93 (d, 2H, J = 7.9 Hz, ArH), 6.65
(d, 2H, J = 8.0 Hz, ArH), 6.10 (s, 1H, =CH), 5.77 (d, 1H, J
= 9.7 Hz, CH-NH), 5.65 (d, 1H, J = 9.8 Hz, CH-NH), 5.10
(d,1H, J = 1.2 Hz, CHH), 4.96 (s, 1H, CHH), 2.06 (s, 3H,
Me), 1.81 (d, 3H, J = 1.4 Hz, Me), 1.79 (s, 3H, Me), 1.66 (s,
3H, Me); 13C-NMR (75 MHz, C6D6, 25 ºC) : 195.5 (C=O),
194.4 (C=O), 143.4, 143.3, 137.7, 136.9, 134.9, 134.3,
moiety. DFT calculations support the involvement of
a Rh(II)-carbenoid produced from the reaction of the
initial triazole and the dirhodium catalyst. This species
is transformed, by reaction with the allenol, into an
(Z)-allenyl vinyl ether intermediate which directly
evolves into the observed reaction product through a
Claisen type [3,3]-sigmatropic rearrangement.
4
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10.1002/adsc.201801424
Advanced Synthesis & Catalysis
129.7 (Ar, 2CH), 129.6 (Ar, 2CH), 129.3 (=CH), 128.9 (Ar,
2CH), 127,4 (Ar. 2CH) 118.9 (=CH2), 58.1 (CH-NH), 26.2
(Me), 23.4 (Me), 21.1 (Me), 21.1 (Me); IR (C6H6, cm–1): 
3272, 1718, 1600, 1160; HRMS (ES): calcd for C23H26NO4S
[M + H]+: 412.15771; found: 412.15969.
(Z)-N-(1-(4-Chlorophenyl)-3-methylene-5,6-dioxo-2-
phenylhept-1-en-4-yl)-4-methylbenzenesulfonamide 3f.
From 60 mg (0.234 mmol) of allenol 1f, and after
chromatography of the residue, gave compound 3f (85 mg,
74%) as a yellow oil; 1H-NMR (300 MHz, C6D6, 25 oC) :
7.58 (d, 2H, J = 8.3 Hz, ArH), 7.23 (d, 2H, J = 8.5 Hz, ArH),
7.09 (m, 4H, ArH), 7.01 (m, 3H), 6.61 (d, 2H, J = 8.0 Hz,
ArH), 6.45 (s, 1H, =CH), 5.78 (d, 1H, J = 9.8 Hz, CH-NH),
5.69 (d, 1H, J = 9.8 Hz, CH-NH), 5.46 (d, 1H, J = 1.2 Hz,
CHH), 5.05 (s, 1H, CHH), 1.81 (s, 3H, Me), 1.51 (s, 3H,
Me); 13C-NMR (75 MHz, C6D6, 25 ºC) : 194.8 (C=O),
194.4 (C=O), 143.5, 140.4, 140.1, 139.9, 137.3, 135.1,
133.8, 130.9 (Ar, 2CH), 130.5 (Ar, 2CH), 129.8 (Ar, 2CH),
128.9 (Ar, 2CH), 128,1 (Ar, CH), 128.0 (=CH), 127.7 (Ar,
2CH), 127.4 (Ar, 2CH),121.6 (=CH2), 58.9 (CH-NH), 23.1
(Me), 21.1 (Me); IR (C6H6, cm–1):  3263, 1719, 1596, 1159;
HRMS (ES): calcd for C27H28ClN2O4S [M + NH4]+:
511.14528; found: 511.14537.
(Z)-N-(1-(4-Chlorophenyl)-2-methyl-3-methylene-5,6-
dioxohept-1-en-4-yl)-4-methylbenzenesulfonamide 3c.
From 72 mg (0.370 mmol) of allenol 1c, and after
chromatography of the residue, gave compound 3c (78 mg,
50%) as a green solid; mp 106–108 ºC; 1H-NMR (300 MHz,
C6D6, 25 oC) : 7.67 (d, 2H, J = 8.3 Hz, ArH), 7.00 (m, 4H,
ArH), 6.69 (d, 2H, J = 8.0 Hz, ArH), 5.94 (d, 1H, J = 1.0 Hz,
=CH), 5.88 (d, 1H, J = 9.8 Hz, CH-NH), 5.61 (d, 1H, J = 9.8
Hz, CH-NH), 5.01 (d, 1H, J = 1.2 Hz, CHH), 4.85 (s, 1H,
CHH), 1.84 (s, 3H, Me), 1.79 (d, 3H, J = 1.5 Hz, Me), 1.71
(s, 3H, Me); 13C-NMR (75 MHz, C6D6, 25 ºC) : 195.6
(C=O), 194.3 (C=O), 143.6, 142.9, 137.3, 136.5, 135.5,
133.0, 130.2 (Ar, 2CH), 129.8 (Ar, 2CH), 128.7 (Ar, 2CH),
128.3 (=CH), 127.7 (Ar, 2CH), 119.1 (=CH2), 57.9 (CH-
NH), 26.0 (Me), 23.5 (Me), 21.1 (Me); IR (C6H6, cm–1): 
3276, 1717, 1595, 1159; HRMS (ES): calcd for
C22H23ClNO4S [M + H]+: 432.10308; found: 432.10452.
(Z)-4-Methyl-N-(3-methylene-5,6-dioxo-2-phenyl-1-(p-
tolyl)hept-1-en-4-yl)benzenesulfonamide 3g. From 66 mg
(0.279 mmol) of allenol 1g, and after chromatography of the
residue, gave compound 3g (64 mg, 49%) as a yellow oil;
1H-NMR (300 MHz, C6D6, 25 oC) : 7.58 (d, 2H. J = 8.2 Hz,
ArH), 7.44 (d, 2H, J = 8.1 Hz, ArH), 7.19 (s, 1H, ArH), 7.02
(dd, 6H, J = 9.5, 7.9 Hz, ArH), 6.66 (s, 1H, =CH), 6.58 (d,
2H, J = 8.1 Hz, ArH), 5.82 (d, 1H, J = 9.8 Hz, CH-NH), 5.59
(d, 1H, J = 9.8 Hz, CH-NH), 5.52 (d, 1H, J = 1.1 Hz, CHH),
5.17 (s, 1H, CHH), 2.09 (s, 3H, Me), 1.77 (s, 3H, Me), 1.50
(s, 3H, Me); 13C-NMR (75 MHz, C6D6, 25 ºC) : 194.8
(C=O), 194.7 (C=O), 143.2, 140.7, 140.5, 138.4, 137.9,
137.5, 133.8, 131.9 (Ar, 2CH), 129.7 (Ar, 2CH), 129.6 (Ar,
2CH), 129.5 (Ar, 2CH), 128.8 (=CH), 128.3 (Ar, CH), 127.7
(Ar, 2CH), 127.6 (Ar, 2CH), 121.4 (=CH2), 59.2 (CH-NH),
23.1 (Me), 21.2 (Me), 21.0 (Me); IR (C6H6, cm–1):  3279,
1718, 1598, 1159; HRMS (ES): calcd for C28H31N2O4S [M
+ NH4]+: 491.19990; found: 491.19980.
(Z)-N-(1-(3-Chlorophenyl)-2-methyl-3-methylene-5,6-
dioxohept-1-en-4-yl)-4-methylbenzenesulfonamide 3d.
From 78 mg (0.40 mmol) of allenol 1d, and after
chromatography of the residue, gave compound 3d (58 mg,
1
o
35%) as a green oil; H-NMR (300 MHz, C6D6, 25 C) :
7.60 (d, 2H, J = 8.3 Hz, ArH), 7.17 (s, 1H, ArH), 7.02 (d,
1H, J = 7.7 Hz, ArH), 6.94 (d, 1H, J = 8.9 Hz, ArH), 6.80 (t,
1H, J = 7.8 Hz, ArH), 6.64 (d, 2H, J = 8.0 Hz, ArH), 5.89
(s, 1H, =CH), 5.58 (d, 1H, J = 10.0 Hz, CH-NH), 5.36 (d,
1H, J = 9.9 Hz, CH-NH), 4.85 (d, 1H, J = 1.2 Hz, CHH),
4.78 (s, 1H, CHH), 1.80 (s, 3H, Me), 1.77 (d, J = 1.5 Hz, 3H,
Me), 1.68 (s, 3H, Me); 13C-NMR (75 MHz, C6D6, 25 ºC) :
195.5 (C=O), 194.0 (C=O), 143.5, 142.8, 139.0, 137.6,
137.5, 134.4, 129.8 (Ar, 2CH), 129.0 (Ar, CH), 128.1 (Ar,
CH), 127.8 (Ar, CH), 127.7 (Ar, CH), 127.3 (Ar, 2CH),
126.9 (Ar, CH), 119.4 (=CH2), 58.0 (CH-NH), 25.8 (Me),
23.4 (Me), 21.1 (Me); IR (C6H6, cm–1):  3273, 1718, 1596,
1160; HRMS (ES): calcd for C22H26ClN2O4S [M + NH4]+:
449.12963; found: 449.13153.
(Z)-N-(2-(4-Bromophenyl)-1-(4-chlorophenyl)-3-
methylene-5,6-dioxohept-1-en-4-yl)-4-
methylbenzenesulfonamide 3h. From 64 mg (0.19 mmol)
of allenol 1h, and after chromatography of the residue, gave
compound 3h (69 mg, 70%) as a yellow oil; 1H-NMR (300
o
MHz, C6D6, 25 C) : 7.54 (d, 2H, J = 8.3 Hz, ArH), 7.19
(dd, 4H, J = 5.8, 2.8 Hz, ArH), 7.09 (m, 2H, ArH), 6.85 (m,
2H), 6.65 (d, 2H, J = 8.0 Hz, ArH), 6.34 (s, 1H, =CH), 5.87
(d, 1H, J = 9.6 Hz, NH-CH), 5.50 (d, J = 9.6 Hz, NH-CH),
5.37 (d, 1H, J = 1.4 Hz, CHH), 5.00 (d, 1H, J = 1.0 Hz,
CHH), 1.88 (s, 3H, Me), 1.61 (s, 3H, Me); 13C-NMR (75
MHz, C6D6, 25 ºC) : 195.1 (C=O), 194.5 (C=O), 143.7,
139.9, 139.1, 138.9, 136.9, 134.7, 133.9, 131.9 (Ar, 2CH),
130.9 (Ar, 2CH), 130.8 (=CH), 129.8 (Ar, 2CH), 129.2 (Ar,
2CH), 128.9 (Ar, 2CH), 127.65 (Ar, 2CH), 122.7, 122.0
(=CH2), 58.7 (CH-NH), 23.2 (Me), 21.2 (Me); IR (C6H6,
cm–1):  3264, 1718, 2280, 1596, 1159; HRMS (ES): calcd
for C27H27BrClN2O4S [M + NH4]+: 591.05379; found:
591.05528.
(Z)-N-(1-(2-Methoxyphenyl)-2-methyl-3-methylene-
5,6-dioxohept-1-en-4-yl)-4-methylbenzenesulfonamide
3e. From 72 mg (0.378 mmol) of allenol 1e, and after
chromatography of the residue, gave compound 3e (61 mg,
1
o
37%) as a green oil; H-NMR (300 MHz, C6D6, 25 C) :
7.65 (d, 2H, J = 8.3 Hz, ArH), 7.32 (dd, 1H, J = 7.5, 1.1 Hz,
ArH), 7.01 (t, 1H, J = 12.5 Hz, ArH), 6.80 (t, 1H, J = 7.4
Hz, ArH), 6.65 (d, 2H, J = 8.0 Hz, ArH), 6.50 (m, 2H, ArH
+ =CH), 5.64 (q, 2H, J = 4.3 Hz, CH-NH), 4.97 (s, 1H,
CHH), 4.93 (s, 1H, CHH), 3.41 (s, 3H, OMe), 1.78 (s, 3H,
Me), 1.77 (d, 3H, J = 1.5 Hz, Me), 1.73 (s, 3H, Me); 13C-
NMR (75 MHz, C6D6, 25 ºC) : 195.8 (C=O), 194.4 (C=O),
157.2, 143.2, 143.1, 137.9, 136.1, 130.4 (Ar, CH), 129.7 (Ar,
2CH), 128.8 (=CH), 127.3 (Ar, 2CH), 126.5, 125.8 (Ar, CH),
120.7 (Ar, CH), 119.2 (=CH2), 110.9 (Ar, CH), 58.2 (CH-
NH), 55.0 (OMe), 25.3 (Me), 23.5 (Me), 21.1 (Me); IR
(C6H6, cm–1):  3270, 1718, 1597, 1160; HRMS (ES): calcd
for C23H26NO5S [M + H]+: 428.15262; found: 428.15404.
(Z)-4-Methyl-N-(2-methyl-3-methylene-5,6-dioxo-1-(p-
tolyl)oct-1-en-4-yl)benzenesulfonamide 3i. From 30 mg
(0.172 mmol) of allenol 1b, and after chromatography of the
residue, gave compound 3i (22 mg, 31%) as a yellow oil;
5
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10.1002/adsc.201801424
Advanced Synthesis & Catalysis
1H-NMR (700 MHz, C6D6, 25 oC) : 7.63 (d, 2H, J = 8.1 Hz,
ArH), 7.17 (d, 2H, J = 8.0 Hz , ArH), 6.92 (d, 2H, J = 7.9
Hz, ArH), 6.61 (d, 2H, J = 7.9 Hz, ArH), 6.09 (s, 1H, =CH),
5.76 (d, 1H, J = 9.8 Hz, CH-NH), 5.41 (d, 1H, J = 9.7 Hz,
CH-NH), 5.07 (s, 1H, =CHH), 4.94 (s, 1H, =CHH), 2.23 (m,
1H, CHH), 2.05 (s, 3H, Me), 1.97 (m, 1H, CHH), 1.80 (m,
3H, Me), 1.76 (s, 3H, Me), 0.67 (t, 3H, J = 7.2 Hz, Me); 13C-
NMR (175 MHz, C6D6, 25 ºC) : 198.2 (C=O), 194.5 (C=O),
143.4, 143.2, 137.7, 136.9, 134.9, 134.3, 129.7 (Ar, 2CH),
129.6 (Ar, 2CH), 129.3 (=CH), 129.0 (Ar, 2CH), 127,7 (Ar,
2CH), 118.9 (=CH2), 58.4 (CH-NH), 29.9 (CH2), 26.2 (Me),
21.1 (Me), 21.0 (Me), 6.7 (Me); IR (C6H6, cm–1):  3662,
2923, 1721, 1164; HRMS (ES): calcd for C24H28NO4S [M +
H]+: 426.17336; found: 426.17256.
[4]a) B. Yang, Y. Qiu, J.-E. Backvall, Acc. Chem. Res. 2018,
51, 1520; b) H.-U. Reissig, R. Zimmer, Synthesis 2017,
49, 3291; c) A. Lledó, A. Pla-Quintana, A. Roglans,
Chem. Soc. Rev. 2016, 45, 2010; d) J. M. Alonso, M. T.
Quirós, M. P. Muñoz, Org. Chem. Front. 2016, 3, 1186;
e) W. Yang, A. S. K. Hashmi, Chem. Soc. Rev. 2014, 43,
2941; f) S. Kitagaki, F. Inagaki, C. Mukai, Chem. Soc.
Rev. 2014, 43, 2956; g) S. Yu, S. Ma, Angew. Chem. Int.
Ed. 2012, 51, 3074.
[5] a) T. Miura, K. Hiraga, T. Biyajima, T. Nakamuro, M.
Murakami, Org. Lett. 2013, 15, 3298; b) T. Miura, T.
Nakamuro, T. Biyajima, M. Murakami, Chem. Lett.
2015, 44, 700.
[6] B. Alcaide, P. Almendros, S. Cembellín, T. Martínez del
(Z)-N-(1-(4-Chlorophenyl)-2-methyl-3-methylene-5,6-
Campo, G. Palop, Chem. Eur. J. 2017, 23, 13754.
dioxooct-1-en-4-yl)-4-methylbenzenesulfonamide
3j.
[7] For the synthesis of 2-substituted 2-amino ketones by
rhodium-catalyzed reaction of N-sulfonyl-1,2,3-
triazoles with 2-alkenols, see: a) T. Miura, T. Tanaka, Q.
Zhao, S. G. Stewart, M. Murakami, Helv. Chem. Acta
2017, 100, e1600320. For the one-pot introduction of
three different bonds onto terminal alkynes through N-
sulfonyl-1,2,3-triazole intermediates, see: b) T. Miura, T.
Tanaka, T. Biyajima, A. Yada, M. Murakami, Angew.
Chem. Int. Ed. 2013, 52, 3883.
From 30 mg (0.154 mmol) of allenol 1c and after
chromatography of the residue, gave compound 3j (35 mg,
51%) as a yellow oil; 1H-NMR (700 MHz, C6D6, 25 oC) :
7.62 (d, 2H, J = 8.2 Hz, ArH), 7.03 (d, 2H, J = 8.5 Hz , ArH),
6.98 (d, 2H, J = 8.5 Hz, ArH), 6.64 (d, 2H, J = 8.0 Hz, ArH),
5.91 (s, 1H, =CH), 5.60 (d, 1H, J = 9.9 Hz, CH-NH), 5.56
(d, 1H, J = 9.9 Hz, CH-NH), 4.96 (s, 1H, =CHH), 4.82 (s,
1H, =CHH), 2.26 (m, 1H, CHH), 2.03 (m, 1H, CHH), 1.80
(s, 3H, Me), 1.77 (d, 3H, J = 1.4 Hz, Me), 0.68 (t, 3H, J =
7.2 Hz, Me); 13C-NMR (175 MHz, C6D6, 25 ºC) : 198.3
(C=O), 194.4 (C=O), 143.5, 143.0, 137.4, 136.6, 135.5,
133.0, 130.2 (Ar, 2CH), 129.8 (Ar, 2CH), 128.7 (=CH),
128.4 (Ar, 2CH), 127,7 (Ar, 2CH), 119.1 (=CH2), 58.1 (CH-
NH), 30.0 (CH2), 26.1 (Me), 21.1 (Me), 6.7 (Me); IR (C6H6,
cm–1):  3272, 1721, 1598, 1163; HRMS (ES): calcd for
C23H28ClN2O4S [M + NH4]+: 463.14528; found: 463.14539.
[8] The preparation of different cores through divergent
reactivity is normally catalyst- or ligand-directed. For
selected reviews, see: a) V. Michelet, P. Y. Toullec, J.-
P. Genet, Angew. Chem. Int. Ed. 2008, 47, 4268; b) J.
Mahatthananchai, A. M. Dumas, J. W. Bode, Angew.
Chem. Int. Ed. 2012, 51, 10954; c) Y.-C. Lee, K. Kumar,
H. Waldmann, Angew. Chem. Int. Ed. 2018, 57, 5212.
[9] CCDC-1839876
contains
the
supplementary
Acknowledgements
crystallographic data for this paper.
[10] In contrast, the donor/acceptor rhodacarbenoid formed
under otherwise identical conditions from 4-aryl-1-
tosyl-1,2,3-triazoles reacted with allenols through C-
attack. Please, see reference 6.
Support for this work by the MINECO and FEDER (Projects
CTQ2015-65060-C2-1-P,
CTQ2015-65060-C2-2-P,
and
CTQ2016-78205-P and CTQ2016-81797-REDC) is gratefully
acknowledged. G. P. and M. T.-P. thank CAM and FEDER (YEI)
for predoctoral contracts.
[11] See Computational Details in the Supporting
Information.
References
[12] Similar early dissociated of the dirhodium catalyst has
been reported, see: a) Y. Liang, H. Zhou, Z.-X. Yu, J.
Am. Chem. Soc. 2009, 131, 17783; b) S. C. Schmid, I. A.
Guzei, I. Fernández, J. M. Schomaker, ACS Catal. 2018,
8, 7907.
§
Responsible for X-ray crystal-structure determination.
[1] For representative reviews, see: a) Y. Li, H. Yang, H.
Zhai, Chem. Eur. J. 2018, 24, 12757; b) Y. Jiang, R. Sun,
X.-Y. Tang, M. Shi, Chem. Eur. J. 2016, 22, 17910; c)
Y. Wang, X. Lei, Y. Tang, Synlett 2015, 26, 2051; d) H.
M. L. Davies, J. S. Alford, Chem. Soc. Rev. 2014, 43,
5151; e) P. Anbarasan, D. Yadagiri, S. Rajasekar,
Synthesis 2014, 46, 3004; f) A. V. Gulevich, V.
Gevorgyan, Angew. Chem. Int. Ed. 2013, 52, 1371.
[13] Experimental procedures as well as full spectroscopic
and analytical data for compounds not included in this
Experimental Section are described in the Supporting
Information. It contains computational details,
experimental procedures, characterization data, and
copies of NMR spectra for all new compounds.
[2] T. Miura, Q. Zhao, M. Murakami, Angew. Chem. Int. Ed.
2017, 56, 16645.
[3] Li et al. recently reported the Rh(III)-catalyzed C−C
coupling of arenes and 4-acyl-1-sulfonyltriazoles: M.
Tian, B. Liu, Ji. Sun, X. Li, Org. Lett. 2018, 20, 4946.
6
This article is protected by copyright. All rights reserved.

10.1002/adsc.201801424
Advanced Synthesis & Catalysis
UPDATES
Chemoselectivity Switching in the Rhodium-
Catalyzed Reactions of 4-Substituted-1-sulfonyl-
1,2,3-triazoles with Allenols: Noticeable
Differences between 4-Acyl- and 4-Aryl-Triazoles
Adv. Synth. Catal. 2018, 360, Page – Page
Benito Alcaide,* Pedro Almendros,* Israel
Fernández, Teresa Martínez del Campo, Guillermo
Palop, Mireia Toledano-Pinedo, and Patricia
Delgado-Martínez
7
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