Asymmetric intramolecular hydroamination of allenes using mononuclear gold catalysts

Article abstract of DOI:10.1021/om4009058

The intramolecular gold-catalyzed asymmetric hydroamination of allenes was studied by screening a series of mononuclear gold(I) and -(III) complexes in combination with silver salts. Among the various chiral monophosphine and diaminocarbene ligands tried,

Full text of DOI:10.1021/om4009058

Article
pubs.acs.org/Organometallics
Asymmetric Intramolecular Hydroamination of Allenes using
Mononuclear Gold Catalysts
Christophe Michon,*,†,‡,§ Florian Medina,†,§ Marc-Antoine Abadie,†,§
and Francine Agbossou-Niedercorn*,†,‡,§
†Universite
́
Lille Nord de France, 59000 Lille, France
‡CNRS, UCCS UMR 8181, 59655 Villeneuve d’Ascq, France
§ENSCL, CCCF, (Chimie-C7), CS 90108, 59652 Villeneuve d’Ascq Cedex, France
S
* Supporting Information
ABSTRACT: The intramolecular gold-catalyzed asymmetric hydroamina-
tion of allenes was studied by screening a series of mononuclear gold(I) and
-(III) complexes in combination with silver salts. Among the various chiral
monophosphine and diaminocarbene ligands tried, the best catalysts arose
from mononuclear gold(I) complexes synthesized from BINOL-based
phosphoramidite ligands. The latest were improved by addition of bulky
substituents at specific positions of the BINOL scaffold. The resulting
gold(I) complexes were combined with selected silver salts to afford
efficient catalysts for intramolecular hydroamination of allenes at room
temperature or below, with good conversions and enantioselectivities.
nucleophile,14,15 gold(I)-catalyzed reactions are considered to
INTRODUCTION
■
be outer sphere in most cases, the metal coordinating the
substrate π system and the nucleophile attacking from the back
side which is far away from the chiral ligand. To overcome such
drawbacks, three strategies have been developed in gold(I)-
catalyzed asymmetric catalysis and to some extent for
hydroamination reactions.
The first strategy implies the use of chiral phosphate anions
such as TRIP in combination with a gold(I) complex to create a
tight ion pair. The resulting chiral binding pocket proved to be
highly efficient for some asymmetric intramolecular hydro-
aminations of allenes.9u,v The chiral phosphate counterion was
shown to act as a ligand bonded to the gold species all along
the hydroamination reaction.16
The second concept involves the use of chiral dinuclear
gold(I) phosphine complexes. Due to the broad choice of bis-
phosphine ligands, this approach has been versatile for some
inter- and intramolecular asymmetric hydroaminations of
allenes and alkenes.6,8,9 Surprisingly, little has been reported
on the role of the second gold atom and the importance of
gold−gold interactions in the catalytic course and therefore in
the asymmetric induction. Moreover, a recent report from
Widenhoefer et al.9a has shed light on difficulties arising from
the use of dinuclear gold catalysts. Indeed, a decreasing
enantioselectivity of the gold-catalyzed intermolecular hydro-
amination of allenes was observed, while in the meantime
conversions increased. As assumed by the authors, whereas one
gold center of the bis(gold) catalyst participates in the allene
Amines are ubiquitous in natural products and are building
blocks and targets for fine chemicals, farming-related chemicals,
and compounds of pharmaceutical interest.1 The hydro-
amination of unactivated alkenes and allenes is the shortest
synthetic route to secondary and tertiary amines. For the
enantioselective synthesis of optically pure amines, the most
studied and privileged hydroamination method is metal
catalysis. Lanthanides and actinides (f block) have been widely
screened, and significant achievements have been reported for
intramolecular reactions.1b,c,g,2 Group 4 metal (Zr, Ti)1c,3 or
main-group-metal (Mg, Li)1c,4 complexes have also led to
valuable results. By comparison, applications in asymmetric
catalysis of transition metals from groups 3−11 (d block)
remain scarce but offer a broader functional group tolerance
and substrate scope.1c,5,8f Moreover, the development of
recoverable catalysts may favor group 3−11 metals, which can
lead to stable and easy to handle organometallic catalysts.
In the past few years, the usefulness of gold6 has been
pointed out in various C−C multiple bond substrates such as
alkynes,6,7 alkenes,6,8 allenes,6,9 and dienes6,10 for both intra-
and intermolecular hydroamination reactions as well as for
diaminations. These results may be quite surprising, in that
gold(I) can be considered as a challenging metal for
asymmetric catalysis, as highlighted recently by Furstner et
̈
al.11 First, these authors stressed gold(I) favors a linear-
dicoordination geometry12 which positions the ligand and the
activated substrate in a trans fashion, thus restricting
asymmetric induction. Tri- and tetracoordination of gold(I)
proved to be less common.12,13 Second, though the reaction
mechanism appears to depend on the nature of the
Received: September 11, 2013
Published: September 23, 2013
© 2013 American Chemical Society
5589
dx.doi.org/10.1021/om4009058 | Organometallics 2013, 32, 5589−5600

Organometallics
Article
activation/C−N bond formation, the second center is
apparently free to coordinate the N-allylic carbamate product,
leading to a less selective catalyst species.
The third strategy developed in gold(I)-catalyzed asymmetric
catalysis involves the use of a mononuclear gold(I) complex
relying mainly on chiral phosphoramidite and diaminocarbene
ligands. Though that approach has been efficient for various
asymmetric organic reactions,6b,17,18 it has until recently11,19
not been applied to hydroamination reactions and remains
promising. While the work reported herein was in progress in
concentrations, the amine addition was fast and favored a two-
step, no intermediate pathway with a high level of chirality
transfer. At low nucleophile concentration, a planar gold allene
intermediate was formed and induced a loss of chirality. In
addition, steric hindrance at the allylic positions was shown to
determine the possible isomeric forms of the bent, cationic η1-
gold(I) transition species.24
On the whole, according to the previous statements, a deep
understanding of gold catalyst activity and the achievement of
highly selective gold-catalyzed hydroaminations of allenes and
alkenes are still challenging areas. Hence, following our interest
on hydroamination and aza-Michael reactions catalyzed by
copper and gold complexes25 and considering the inadequacy
of applications of chiral mononuclear gold(I) species to
asymmetric hydroamination,11,19 we wish to report herein our
own results on asymmetric intramolecular hydroaminations of
allenes using mononuclear gold catalysts.
our laboratory, Furstner et al. reported seminal examples of
̈
gold(I) phosphoramidite catalysts for asymmetric intramolec-
ular hydroamination reactions of allenes.11
From a mechanistic point of view, gold(I)-catalyzed
hydroamination reactions proved to be intriguing. Indeed,
with poor nucleophiles, gold cationic complexes were shown to
be the main catalysts, as no Brønsted acid was generated by
coordination of the cationic gold species with weakly basic
amine reagents.14 However, stronger nucleophiles, including
ammonia and hydrazine, proved to lead to two potent catalysts,
a Brønsted acid and a gold amine complex. The latest was
shown to catalyze exclusively the hydroamination reaction in
several examples. In the case of enantiopure allene substrates,
the reaction with amines proceeded smoothly with high
chirality transfer, thus excluding the acid species as the main
catalyst.15 Though they suffer from a narrow reaction scope
almost limited to disubstituted allenes, such chirality transfer
and memory of chirality have emerged as useful tools in organic
chemistry.15j Moreover, the nucleophilicity of the amine
reagent seems to direct the nature of the catalyst species for
the hydroamination reaction. Whereas an outer-sphere
mechanism seems to be applied to weak amines which add in
an anti fashion to the gold complex,9f,t,x,14 an inner-sphere
mechanism may be preferred for stronger nucleophiles.9p,15h
However, some gold amide complexes were recently shown to
be unreactive in the amination of alkynes, suggesting that the
inner-sphere mechanism for addition to π bonds may not be
preferred in some cases.20 Interestingly, Ujaque et al. have
compared by calculations the mechanisms of acid- and gold-
catalyzed hydroaminations of alkenes and dienes.21 Whereas
the acid-catalyzed process was shown to be concerted, the gold-
catalyzed reaction was found to be stepwise for the nucleophile-
assisted and counterion-assisted pathways. Indeed, a proton-
transfer agent, i.e. the nucleophile or the counterion, was crucial
in lowering the energy barrier for the proton transfer step.
Toste, Goddard, et al. studied through calculations and
experiments the intramolecular aminoauration of unactivated
alkenes, providing evidence of an anti addition mechanism for
alkene aminoauration.22 However, once prepared, such
assumed catalytic intermediates did not allow the hydro-
amination reaction to proceed, leading only to the unreacted
alkenes. The authors concluded that was due to the high energy
barrier calculated for the protodeauration step.22 The lattest
was recently shown to be also the turnover-limiting step for
gold(I)-catalyzed intramolecular allene hydroalkoxylation.23a
The active mono(gold)vinyl complex proved to be in
equilibrium with an inert off-cycle bis(gold) vinyl complex. In
addition, the reversibility of C−Nuc bond formation was
evidenced and might play an important role in the stereo-
selectivity of gold(I)-catalyzed hydrofunctionalization.22,23
Furthermore, the nucleophile concentration proved to be
critical for the stereochemical outcome of intermolecular
hydroamination reactions of allenes.9h At high nucleophile
RESULTS AND DISCUSSION
■
In order to study the substituent effect on amine reactivity, we
performed preliminary studies on the racemic intramolecular
hydroamination of allene with amine substrates 1a−e using
IPrAuCl as precatalyst along with 5 mol % of AgOTf (Table 1).
The catalysis proceeded well for electron-poor amine substrates
(entries 1−4). Indeed, almost quantitative conversions were
obtained in 1 h at 30 °C.
Table 1. Amine Substitution Effect on Reactivity
a
entry
reagent
R
product conversion (%)
1
2
3
4
5
1a
1b
1c
1d
1e
CBz
Ts
>95 (2a)
>95 (2b)
>95 (2c)
>95 (2d)
Boc
CONHPh
Bn
b
>77 (2e)
a
b
Measured by NMR. At 80 °C for 66 h in toluene.
By comparison, a poor reactivity was observed for the
electron-rich N-benzyl allene amine 1e, which required a
stronger and much longer heating (80 °C, 66 h) to reach 77%
conversion (entry 5). The first study on asymmetric intra-
molecular hydroamination of allenes using mononuclear gold
catalysts was achieved by screening various chiral ligands and
complexes for the reaction of reagent 1a (Table 2 and Chart 1).
A catalytic amount of AgOTf was used along with each gold
complex in order to generate in situ the cationic active species.
As already reported, N-allenyl carbamates proved to be
privileged substrates when dinuclear gold(I) catalysts were
used.9t,x,z In addition, as highlighted in the Introduction, the
carbamate function was shown to participate in a low-barrier
mechanistic hydroamination pathway through carbamate
tautomerization assisted by a triflate anion acting as a proton
shuttle.21 Our screening started with mononuclear gold(I)
complexes 3 and 5 based on diaminocarbene ligands,26 but
poor conversions and enantioselectivities were obtained (Chart
1 and Table 2 entries 1 and 3). The new gold(III)
diaminocarbene complexes 4 and 6 were synthesized and
5590
dx.doi.org/10.1021/om4009058 | Organometallics 2013, 32, 5589−5600

Organometallics
Article
Table 2. Screening of Mononuclear Gold(I) and -(III)
Catalysts
Scheme 1. Mononuclear Diaminocarbene Gold(III) Catalyst
Synthesis
a
ligand (Lx) or complex
(Y)
conversion
(%)
ee
(%)
b
c
entry
configuration
1
2
3
4
(R,R)-3
7
>95
24
(R,R)-4
14
3
R
S
(R,R)-5
(S,S)-6
0
d
5
(S,R,R)-L1
(R,S,S)-L1
(S,R)-L2
(S,R,R)-L3
(R,R,R)-L4
(R)-L5
>95
>95
50
42
41
13
6
S
R
S
S
R
R
S
S
such an effect has already been reported to significantly
enhance the activity of gold-catalyzed hydrofunctionalization of
allenes.9p We next switched to mononuclear gold(I) complexes
containing phosphoramidite ligands (Chart 1 and Table 2).
First, L1 based on BINOL and the Whitesell amine was used,
affording product 2a with high conversion (95%) and average
enantiomeric excess (ee) (42%) (Table 2, entries 5 and 6). The
enantioselectivity of 2a proved to be stable over time, the same
ee value being measured at 1 and 20 h of reaction (entry 5). It
is worth noting that the ee of the reaction product 2a appeared
to be proportional to the ee value of the chiral ligand L1,
suggesting the absence of nonlinear effects (see the Supporting
Information, Table S1 and Figure S1).27 Next, as shown by the
use of phosphoramidite ligands L2−L5, any change in the chiral
amine fragment proved to have a negative effect on the
conversion and/or the enantioselectivity (Table 2, entries 7−
10). Moreover, the switch from the Monophos ligand L5 to L6,
that is to say a change from a BINOL scaffold to a partially
hydrogenated one, led to a decrease in the conversion (entries
10 and 11) and demonstrated the negative effect of an increase
in the ligand dihedral angle. The change to ligand L8 based on a
6
7
8
10
9
>95
>95
70
33
16
17
33
10
11
12
13
14
15
(S)-L6
(S)-L7
>95
0
(S,S)-L8
(R,R,R)-L9
(R,R)-L10
>95
>95
47
15
S
S
a
b
Measured by 1H NMR. Measured by HPLC at 220 nm.
c
Determined by HPLC by comparison with previous work (see the
d
Supporting Information). Same result for 1 h reaction.
tested in the asymmetric intramolecular hydroamination of
allene 1a (Scheme 1 and Table 2, entries 2 and 4). Gold(III)
precatalyst 4 displayed a high conversion and a poor
enantioselectivity, whereas complex 6 was inactive. The result
obtained using 4 can be explained by the coordination of one of
the neighboring methoxy substituents to the gold(III) center;
Chart 1. Ligands and Complexes Used for the Screening of Mononuclear Gold(I) and -(III) Catalysts
5591
dx.doi.org/10.1021/om4009058 | Organometallics 2013, 32, 5589−5600

Organometallics
Article
biphenyl scaffold had an even more dramatic effect, no
conversion being observed (entry 13). It was worth noting
that the 3,3′-substitution of the BINOL backbone by two
methyl substituents (L7) led to a significant increase in the
enantioselectivity (from 16 to 33% ee, entries 10 and 12). The
spiro phosphoramidite ligand L9 afforded the best ee (47%),
whereas the taddol-based ligand L10 gave a poor one (15%)
(entries 14 and 15). Except for these last two ligands, which are
based on different diol scaffolds, it appeared that the chirality of
the BINOL fragment was the key factor controlling the
stereochemistry of the product 2a, both displaying the same
configuration (entries 5−12).
5). Regarding the enantioselectivity, CBz and Boc substituents
were by far the most appropriate with values of 42 and 41% ee,
the N-urea allenyl substrate leading to a 28% ee (entries 1, 3,
and 4). By offering a 32% ee, the tosyl group was less selective
and induced a reversal of the stereoselectivity (entry 2). No
enantioselectivity could be observed for N-benzyl allenyl
reagent 1e (entry 5). The mononuclear gold(I) catalyst based
on the phosphoramidite ligand L1 appeared to be sensitive to
substituents on the allene moiety. For example, N-carbamate
tris-substituted allene substrate 1f afforded only a 22% ee (entry
6). The change of substituents at the C2 position of the 4,5-
hexadienyl chain had an even more critical effect on the
stereochemical outcome of the hydroamination reaction,
enantioselectivities being very low for methyl and cyclohexyl
substituents (entries 1, 7, and 8). A similar trend was observed
when dinuclear gold(I) catalysts were used, though enantiose-
lectivities were higher.9x
In comparison to mononuclear gold(I) catalysts, dinuclear
gold(I) catalysts did not afford better conversions and
enantioselectivities under the same experimental conditions
(Table 3 and Chart 2). A maximum of 90% conversion and
We next focused on the influence of the anion on the
conversion and enantiomeric excess (Table 5). Among the
various silver salts screened, triflate, tosylate, and perchlorate
anions appeared to be the most appropriate (entries 1−10).
Moreover, when no ligand or gold was used, silver triflate did
not catalyze the hydroamination of 1a (entry 6). When product
2a was formed, the enantioselectivity and the nature of the ion
pairing were found to be unrelated under our reaction
conditions. A gold(I) catalyst based on L1 proved to be
unreactive when associated with chiral TRIP phosphate anion,
even when stronger reaction conditions were used (entries 11
and 12).
Table 3. Screening of Dinuclear Gold(I) Catalysts
a
b
c
entry
1
ligand (Lx)
conversion (%)
ee (%)
42
configuration
(S)-L15
90
0
R
d
2
(S)-L16
3
4
5
6
(S)-L17
90
90
90
90
0
21
18
7
R
S
(R,R)-L18
(R,R)-L19
(R,R)-L20
(S,S)-L21
(S,S)-L22
To pursue our study on the influence of reaction parameters,
various solvents were screened (Table 6). Except for
acetonitrile (entry 13), the reaction ran quite well in polar or
apolar solvents (entries 1−12). However, we noticed that the
enantiomeric excesses were higher when reactions were
performed in apolar aromatic solvents (entries 3−7) and
concluded that tight ion pairs were critical to reach high levels
of enantioselectivity. When the temperature was decreased to 0
°C and to −20 °C, the reaction did not proceed in
dichloromethane and THF (entries 2 and 9) but did run
smoothly in toluene, reaching respectively 62 and 67% ee
(entries 4 and 5). That last enantioselectivity was obtained with
a reduced conversion, suggesting a longer reaction time was
needed. Moreover, the reaction outcome remained unchanged
upon removal of AgCl by filtration through Celite of the
phosphoramidite mononuclear gold(I) cationic species pre-
pared prior to the catalysis (entry 1). Hence, no “silver effect”
was observed in our gold-catalyzed hydroamination reactions.29
Considering our results and the general trends in gold(I)-
catalyzed asymmetric reactions,17 a series of phosphoramidite
ligands related to L1 was foreseen. Based on the Whitesell
amine and on BINOL, these ligands carry bulky substituents at
the 3,3′-positions of the BINOL scaffold (see Chart 3, Table 7,
and the Supporting Information).30 As illustrated by some
MM2 calculations, we were confident such phosphoramidite
ligands would afford an enhanced steric hindrance around the
gold(I) catalytic center and would lead to a better
enantioselectivity (see the Supporting Information, Chart S1).
The new phosphoramidite ligand L14 was synthesized by
reaction of the functionalized BINOL (R)- or (S)-8d with PCl3
and the Whitesell amine 7 of defined configuration (Scheme 2).
All of the other 3,3′-substituted ligands (Chart 3) were
prepared according to the same synthetic pathway and
previously reported procedures (see the Supporting Informa-
S
21
R
e
7
e
8
0
a
b
)Measured by 1H NMR. )Measured by HPLC at 220 nm.
c
)Determined from HPLC by comparison of previous work.
d
e
)Performed with AgClO4 in toluene. )The same results were
obtained with a 1/1 gold/ligand ratio.
42% ee was reached with the biphep ligand L15 (entry 1).
However, it was previously reported that a gold(I) catalyst
based on L15 could lead to a much higher enantioselectivity for
product 2a, provided different anions, solvents, and reaction
temperatures were used.9x Surprisingly, the change to L16 with a
Segphos backbone led to complete loss of reactivity (entry 2).
The use of trans ligands L17 and L18 (entries 3 and 4) or P-
chiral phosphines L19 and L20 (entries 5 and 6) afforded 2a in
high conversions but moderate enantioselectivities. Finally, the
use of chiral secondary phosphine oxides L21 and L22 did not
allow any reaction (entries 7 and 8).
Regarding our screening of mononuclear gold(I) complexes
issued from phosphoramidite ligands, we chose to focus on
ligand L1, even though L9 was found to give the best results of
our study. Indeed, BINOL-based phosphoramidite ligands17
appeared to afford us broader possibilities of derivatization in
comparison to the spiro-based ligands.28
In order to check the substituent effects on the selectivity of
the reaction, we screened several substrates using ligand L1
(Table 4).
First, we reinvestigated the substituent effect on amine
reactivity. All reactions afforded an almost quantitative
conversion at 30 °C in 20 h, except for N-benzyl allenyl
substrate 1e, which required a 100 °C heating (Table 4, entry
5592
dx.doi.org/10.1021/om4009058 | Organometallics 2013, 32, 5589−5600

Organometallics
Article
Chart 2. Ligands Used for the Screening of Dinuclear Gold(I) Catalysts
Table 4. Substituent Effects on Enantioselectivity
Table 5. Silver Salt Screening
a
b
c
entry
AgX
conversion (%)
ee (%)
configuration
a
b
1
2
3
4
5
AgSbF6
>95
85
24
41
36
26
42
S
S
S
S
S
entry
R1
CBz
R2
R3
conversion (%)
ee (%)
AgClO4
AgBF4
1
2
3
4
Ph
Ph
Ph
Ph
Ph
Ph
Me
H
H
H
H
H
Me
H
H
>95 (2a)
>95 (2b)
>95 (2c)
>95 (2d)
>95 (2e)
93 (2f)
42
−32
41
28
0
>95
>95
>95
0
Ts
AgNTf2
AgOTf
Boc
CONHPh
Bn
d
6
AgOTf
c
5
e
7
AgOTs
>95
0
46
19
R
S
6
7
8
CBz
CBz
CBz
22
9
8
AgPNB
AgNO3
>95 (2g)
9
0
−(CH2)5−
>95 (2h)
c
7
10
11 ,
AgBARF
(R)-AgTRIP
(S)-AgTRIP
>95
0
a
b
Measured by 1H NMR. Measured by HPLC. Performed at 100 °C
fg
for 20 h.
g
12
0
a
b
Measured by 1H NMR. Measured by HPLC at 220 nm.
tion). First, catalytic tests were performed on the most
appropriate substrate, i.e. 1a, performing the reactions under
our best experimental conditions, in toluene at −20 °C for 20 h
with AgOTf (Table 7, Chart 3). We started by studying L9
again, but no significant increase of enantioselectivity was
observed and conversion was reduced (entry 1). The use of
phosphoramidite ligand L1 confirmed the enhanced ee
previously obtained and showed a close correlation between
conversions and the ligand configurations (entries 2 and 3). We
next studied the four stereoisomers of phosphoramidite ligand
c
d
Determined by HPLC (see the Supporting Information). Performed
e
f
without (Me)2SAuCl and L1. Performed with (R,S,S)-L1. For 74 h.
g
Less than 10% conversion in toluene at 100 °C for 26 h.
(entry 7). A final attempt was run at −40 °C, but no reaction
occurred (entry 8). Substrates 1b−d,g were then tested using
ligand (S,R,R)-L11 at −20 °C for 20 h. By offering a 44% ee,
compound 1b, bearing a tosyl group, was less selective and
induced a reversal of the stereoselectivity, conversion being
high (entry 9). Compound 1c with a Boc substituent afforded a
good enantioselectivity (66% ee), but conversion was moderate
(entry 10). The N-urea allenyl substrate 1d led to average
enantiomeric excess and conversion (entry 11). Finally, the
L
11 bearing phenyl substituents. Again, conversions were highly
dependent on the ligand configuration, values being quite
disparate (entries 4−7). With an average 55% conversion and a
good 78% ee, the ligand (S,R,R)-L11 afforded the best result
5593
dx.doi.org/10.1021/om4009058 | Organometallics 2013, 32, 5589−5600

Organometallics
Article
stereochemistry of the product 2a; both were shown to display
the same configuration. This same stereoselectivity was
observed for two configurations of phosphoramidite ligand
L12 bearing biphenyl substituents (entries 13 and 14). Product
2a was afforded in high 95% conversions and good 78% ee for
(R,S,S)-L12. The latter was allowed to react with reagent 1a at
−30 °C, but the enantioselectivity was not improved and a low
conversion was obtained (entry 15). Phosphoramidite ligand
L13 functionalized by anthracenyl substituents led also to high
conversions (95%) but average to modest ee values (21−40%)
were obtained (entries 16 and 17). Finally, phosphoramidite
ligand L14 bearing benzhydryl substituents afforded 2a in good
to high conversions (75−90%) along with low to good ee
values (4−66%), the configuration R,S,S being the best (entries
18−20). It was worth noting that the chirality of the L14
BINOL fragment no longer controlled the stereochemistry of
the product 2a, as both displayed opposite configurations
(entries 18 and 20). Regarding all these synthesized
phosphoramidite ligands, the best asymmetric induction was
obtained by combining opposite stereochemical configurations
on, respectively, the BINOL fragment and the Whitesell amine
part, favored ligand configurations being R,S,S and S,R,R. The
best conversions and ee values were obtained by running the
reaction at −20 °C and using the phosphoramidite ligand
(R,S,S)-L12.
Table 6. Solvent Screening
a
b
entry
solvent
CH2Cl2
T (°C)
conversion (%)
ee (%)
42
c
1
30
0
>95
0
d
2
CH2Cl2
toluene
3
4
5
6
7
8
30
0
>95
>95
25
52
62
67
57
51
47
toluene
toluene
−20
30
30
30
0
benzene
m-xylene
THF
>95
>95
>95
0
d
9
THF
10
11
12
13
1,4-dioxane
CH3NO2
CF3CH2OH
30
30
30
30
>95
>95
>95
10
51
31
29
36
CH3CN
a
b
c
1
Measured by H NMR. Measured by HPLC at 220 nm. The same
result was obtained using catalyst purified by filtration over Celite.
d
The same result was obtained at −20 °C for 20 h.
reaction of compound 1g at 0 °C afforded a 68% conversion
along with a moderate enantioselectivity of 15% in spite of the
presence of a Cbz substituent (entry 12). This confirmed any
change of substituent at the C2 position of the reagent 4,5-
hexadienyl chain led to a critical decrease of the product
enantiomeric excess. As previously observed for L1, the chirality
of the L11 BINOL fragment was the key factor controlling the
CONCLUSIONS
■
The gold-catalyzed asymmetric intramolecular hydroamination
of allenes was studied by screening a series of mononuclear
gold(I) and -(III) complexes in combination with silver salts.
Among the various chiral monophosphine and diaminocarbene
ligands tried, the best catalysts arose from mononuclear gold(I)
Chart 3. Tuned Phosphoramidite Ligands Used for the Screening of Mononuclear Gold(I) Catalysts
5594
dx.doi.org/10.1021/om4009058 | Organometallics 2013, 32, 5589−5600

Organometallics
Article
Table 7. Screening of Mononuclear Gold(I) Catalysts Based on Tuned Phosphoramidite Ligands
a
b
c
entry
R1
CBz
R2
ligand (Lx)
T (°C)
conversion (%)
ee (%)
configuration
1
Ph
Ph
Ph
Ph
Ph
Ph
Ph
Ph
Ph
Ph
Ph
Me
Ph
Ph
Ph
Ph
Ph
Ph
Ph
Ph
(R,R,R)-L9
(S,R,R)-L1
(R,S,S)-L1
(R,S,S)-L11
(R,R,R)-L11
(S,S,S)-L11
(S,R,R)-L11
(S,R,R)-L11
(S,R,R)-L11
(S,R,R)-L11
(S,R,R)-L11
(S,R,R)-L11
(R,R,R)-L12
(R,S,S)-L12
(R,S,S)-L12
(R,R,R)-L13
(R,S,S)-L13
(R,S,S)-L14
(S,R,R)-L14
−20
−20
−20
−20
−20
−20
−20
−40
−20
−20
−20
0
30 (2a)
5 (2a)
50
65
67
71
31
31
78
R
S
2
CBz
CBz
CBz
CBz
CBz
CBz
CBz
Ts
3
25 (2a)
5 (2a)
R
R
R
S
4
5
>95 (2a)
30 (2a)
2a 55
6
7
S
8
2a 0
9
>95 (2b)
26 (2c)
62 (2d)
68 (2g)
>95 (2a)
>95 (2a)
17 (2a)
>95 (2a)
>95 (2a)
75 (2a)
86 (2a)
90 (2a)
−44
66
52
15
24
78
78
40
21
66
16
4
10
11
12
13
14
15
16
17
18
19
20
Boc
CONHPh
CBz
CBz
CBz
CBz
CBz
CBz
CBz
CBz
−20
−20
−30
−20
−20
−20
−20
−20
R
R
R
R
R
R
R
R
CBz
(S,S,S)-L14
a
b
c
1
Measured by H NMR. Measured by HPLC at 220 nm. Determined from HPLC by comparison with previous work (see the Supporting
Information).
Scheme 2. Synthesis of 3,3′-Dibenzhydryl-Substituted Phosphoramidite Ligand L14
MHz), 13C (75 MHz), and 31P (121 MHz) spectra were acquired on a
complexes built on BINOL-based phosphoramidite ligands.
The latter were improved by addition of bulky substituents at
the specific 3,3′-positions of the BINOL scaffold. The resulting
gold(I) complexes were combined with selected silver salts to
afford efficient catalysts for intramolecular hydroaminations of
allenes at room temperature or below, with good conversions
and enantioselectivities. In the future, such mononuclear
gold(I) catalysts may be a good alternative solution to
dinuclear gold(I) catalysts, when selectivity issues are
encountered owing to the presence of two gold centers, the
first being part of the most active and selective catalyst and the
second leading to a competing nonselective catalyst species.9a
Bruker Avance spectrometer. Chemical shifts (δ) are reported
downfield of Me4Si in ppm, and coupling constants are expressed in
Hz. 1,3,5-Trimethoxybenzene and 1,2,4,5-tetrachlorobenzene were
used as internal standards when needed. Infrared spectra were
recorded on a ThermoScientific-Nicolet 6700 spectrometer; the
samples were prepared with KBr powder. HPLC was performed on
a Hitachi LaChromElite equipment with a micropump, a Peltier oven,
and a DAD detector. HRMS-ESI analyses were performed at the
CUMA Pharmacy Department, Universite
Elemental analyses were performed at UCCS, Universite
́
Lille Nord de France.
Lille Nord de
́
France. AuS(Me)2Cl was prepared following related procedures.31,32
BARF and TRIP silver salts were prepared as reported.33,34 Amino
allene substrates were synthesized following reported procedures: 1a,9z
1b,35 1c,9z 1d,9f 1e,35 1f,35 1g,9x 1h.11 Except for L14, phosphoramidite
ligands were prepared according to reported procedures: L11,30e L12,30e
L13.17b Gold(I) diaminocarbene complexes 3 and 5 were synthesized
as reported.26 See the Supporting Information for further details.
General Procedure for Ligand Screening. In a glovebox,
AuS(Me)2Cl (2.9 mg, 0.01 mmol) and the corresponding ligand (0.01
mmol) were placed in a first Schlenk flask. Dry dichloromethane (1
mL) was added under a nitrogen atmosphere, and the resulting
EXPERIMENTAL SECTION
■
General Remarks. All solvents were dried using standard methods
and stored over molecular sieves (4 Å). All silver salts were weighted
in a glovebox. All reactions were carried out under a dry nitrogen
atmosphere and were at least repeated twice. Analytical thin-layer
chromatography (TLC) was performed on Macherey precoated 0.20
mm silica gel Alugram Sil 60 G/UV254 plates. Flash chromatography
was carried out with Macherey silica gel (Kielselgel 60). 1H (300
5595
dx.doi.org/10.1021/om4009058 | Organometallics 2013, 32, 5589−5600

Organometallics
Article
mixture was stirred at room temperature for 2 h. Afterward, the solvent
was evaporated under vacuum and the resulting solid was dried 30 min
before addition of AgOTf (2.3 mg, 0.009 mmol) in a glovebox. Dry
dichloromethane (1 mL) was added under nitrogen, and the resulting
solution was stirred for 30 min before being transferred to a second
Schlenk flask containing amino allene substrate 1a (68.9 mg, 0.18
mmol). After 20 h of stirring at 30 °C, the solution was filtered
through a pad of silica gel using dichloromethane as solvent. After
evaporation of solvent under vacuum, the resulting oil was analyzed by
1H NMR and HPLC.
by flash chromatography on silica gel using a 1/1 mixture of petroleum
ether and toluene (Rf = 0.6). After evaporation of solvents under
vacuum and further washes with acetone and petroleum ether,
compound (R,S,S)-L14 was obtained as a white solid (0.12 mmol, 105
mg, 71%). 1H NMR (300 MHz, CDCl3): δ 1.56 (br s, 3H), 2.15 (br s,
3H), 4.47 (br s, 1H), 4.83 (br s, 1H), 5.90 (s, 1H), 6.27 (s, 1H), 6.75−
7.20 (m, 20H), 7.20−7.60 (m, 18H), 7.66 (d, J = 8.3 Hz, 1H), 7.74 (d,
J = 8.3 Hz, 1H). 31P NMR (121.5 MHz, CDCl3): δ 142.5. 13C NMR
(75 MHz, CDCl3): δ 50.3 (CH3), 50.3 (CH3), 52.8 (CH), 122.8 (C),
122.8 (C), 124.6 (CH), 124.7 (CH), 125.8 (CH), 125.9 (CH), 126.3
(CH), 126.4 (CH), 126.7 (CH), 126.9 (CH), 127.2 (CH), 127.9
(CH), 128.3 (CH), 128.3 (CH), 128.4 (CH), 128.5 (CH), 128.5
(CH), 128.8 (CH), 129.4 (CH), 129.7 (C), 130.0 (CH), 130.3 (CH),
131.0 (C), 131.4 (CH), 132.0 (C), 132.5 (C), 135.5 (C), 135.6 (C),
142.6 (C), 143.2 (C), 144.3 (C), 144.4 (C), 148.2 (C), 148.5 (C),
148.6 (C). HMRS (ESI): m/z calcd for C62H51NO2P 872.3652
General Procedure for Silver Salt Screening. In a glovebox,
0.01 mmol of AuS(Me)2Cl (2.9 mg) and 0.01 mmol of (S,R,R)-L1 (5.4
mg) were placed in a first Schlenk flask. Dry dichloromethane (1 mL)
was then added under a nitrogen atmosphere, and the resulting
mixture was stirred for 2 h at room temperature. Afterward, the solvent
was evaporated under vacuum and the resulting solid was dried 30 min
before addition of AgOTf (0.009 mmol) in a glovebox. Dry
dichloromethane (1 mL) was added under a nitrogen atmosphere,
and the resulting solution was stirred for 30 min before being
transferred to a second Schlenk flask containing amino allene substrate
1a (0.18 mmol, 68.9 mg). After 20 h of stirring at 30 °C, the solution
was filtered through a pad of silica gel using dichloromethane as
solvent. After evaporation of solvents under vacuum, the resulting oil
20
[MH+], found 872.3644. [α]D = +62° (CH2Cl2, c = 0.1 g/100 mL).
( S , S , S ) - ( − ) - ( 2 , 6 - D i b e n z h y d r y l - 3 , 5 - d i o x a - 4 -
phosphacyclohepta[2,1-a;3,4-a′]dinaphthalen-4-yl)bis(1-
phenylethyl)amine ((S,S,S)-L14). This compound was prepared from
(S)-8d and amine (S,S)-7 using the same procedure as for (R,S,S)-L14.
20
[α]D = −187° (CH2Cl2, c = 0.1 g/100 mL).
( S , R , R ) - ( − ) - ( 2 , 6 - D i b e n z h y d r y l - 3 , 5 - d i o x a - 4 -
phosphacyclohepta[2,1-a;3,4-a′]dinaphthalen-4-yl)bis(1-
phenylethyl)amine ((S,R,R)-L14). This compound was prepared
from (R)-8d and amine (R,R)-7 using the same procedure as for
1
was analyzed by H NMR and HPLC.
General Procedure for Solvent Screening. In a glovebox,
AuS(Me)2Cl (0.01 mmol, 2.9 mg) and (R,S,S)-L1 (0.01 mmol, 5.4
mg) were added to a Schlenk flask. Dry solvent (1 mL) was then
added under a nitrogen atmosphere, and the resulting mixture was
stirred for 2 h at room temperature. Afterward, the solvent was
evaporated under vacuum and the resulting solid was dried 30 min
before addition of AgOTf (0.009 mmol, 2.3 mg) in a glovebox. The
corresponding dry solvent (1 mL) was added under a nitrogen
atmosphere, and the resulting solution was stirred for 30 min before
being transferred in a second Schlenk flask containing amino allene
substrate 1a (0.18 mmol, 68.9 mg). After 20 h of stirring at 30 °C, the
solution was filtered through a pad of silica gel using dichloromethane
as solvent. After evaporation of solvents under vacuum, the resulting
20
(R,S,S)-L14. [α]D = −39° (CH2Cl2, c = 0.1 g/100 mL).
Benzyl-2,2-dimethyl-4,5-hexadienylcarbamate (1g). Follow-
ing a related procedure,9x dry diisopropylamine (1.7 mL, 10 mmol)
and dry THF (5 mL) were placed in an oven-dried Schlenk flask. The
solution was then cooled to 0 °C and nBuLi (1.2 equiv, 12 mmol, 7.5
mL, 1.6 M solution) was added under nitrogen. After 1 h of stirring at
room temperature, dry isobutyronitrile (0.9 mL, 10 mmol) diluted in
dry THF (3 mL) was added under nitrogen. After another 1 h of
stirring at room temperature, propargyl bromide (1.2 equiv, 12 mmol,
1.5 mL, 80 wt % solution in toluene) was added under nitrogen and
the solution was stirred overnight at room temperature. Then, 10 mL
of distilled water was added, the layers were separated, and the
aqueous layer was extracted with Et2O (3 × 10 mL). The combined
organic layers were dried over MgSO4 and concentrated under vacuum
to afford 2,2-dimethyl-4-pentynenitrile as a slightly yellow oil, which
was used for the next step without any further purification due to its
volatility. In an oven-dried Schlenk flask, paraformaldehyde (2 equiv,
20 mmol, 0.63 g) and CuBr (0.4 equiv, 4.2 mmol, 0.6 g) were diluted
in dry 1,4-dioxane (10 mL). Then, dry diisopropylamine (2 equiv, 20
mmol, 3 mL) and the oil obtained previously were added under
nitrogen. After it was stirred at reflux overnight, the solution was
filtered through a pad of silica gel with dichloromethane/petroleum
ether (1/1). Evaporation of solvents afforded 2,2-dimethylhexa-4,5-
dienenitrile as a slightly yellow oil which was used without any further
purification step due to its volatility. In an oven-dried Schlenk flask,
dry Et2O (20 mL) and LiAlH4 (26 mmol, 0.5 g) were added to the oil
obtained previously. After it was stirred at room temperature
overnight, the solution was neutralized at 0 °C with H2O and
NaOHaq (6 M). After filtration through a pad of Celite, the organic
layer was dried over MgSO4 and concentrated under vacuum to afford
2,2-dimethylhexa-4,5-dien-1-amine as a slightly yellow oil which was
used without any further purification step due to its volatility. The
resulting product was placed in a flask with benzyl chloroformate (1.2
equiv, 12 mmol, 1.6 mL), ethanol (40 mL), distilled water (16 mL),
and NaHCO3aq (1 M, 24 mL). After 45 min of stirring at room
temperature, saturated NaClaq (50 mL) was added, the layers were
separated, and the resulting aqueous layer was extracted with Et2O (3
× 10 mL). The combined organic layers were dried over MgSO4 and
concentrated under vacuum to afford a colorless oil which was purified
by by flash chromatography using a 9/1 petroleum ether/EtOAc
solvent mixture (Rf = 0.4). After evaporation of solvents under
vacuum, compound 1g was obtained as a colorless oil (1.3 mmol, 0.34
1
oil was analyzed by H NMR and HPLC.
General Procedure for Temperature Screening. In a glovebox,
AuS(Me)2Cl (0.01 mmol, 2.9 mg) and (R,S,S)-L1 (0.01 mmol, 5.4
mg) were added to a Schlenk flask. Dry toluene (1 mL) was then
added under a nitrogen atmosphere, and the resulting mixture was
stirred for 2 h at room temperature. Afterward, the solvent was
evaporated under vacuum and the resulting solid was dried 30 min
before addition of AgOTf (0.009 mmol, 2.3 mg) in a glovebox. Dry
toluene (1 mL) was then added under a nitrogen atmosphere, and the
resulting solution was stirred for 30 min before being transferred to a
second Schlenk flask containing amino allene substrate 1a (0.18 mmol,
68.9 mg). After 20 h of stirring at the corresponding temperature, the
solution was filtered through a pad of silica gel using dichloromethane
as solvent. After evaporation of solvents under vacuum, the resulting
1
oil was analyzed by H NMR and HPLC.
( R , S , S ) - ( + ) - ( 2 , 6 - D i b e n z h y d r y l - 3 , 5 - d i o x a - 4 -
phosphacyclohepta[2,1-a;3,4-a′]dinaphthalen-4-yl)bis(1-
phenylethyl)amine ((R,S,S)-L14). In the first flame-dried Schlenk
flask, dry and degassed THF (1 mL) was placed under nitrogen and
cooled to 0 °C. NEt3 (1.02 mmol, 138 μL) followed by PCl3 (0.17
mmol, 85 μL of a 2 M solution) were added under nitrogen, and the
mixture was stirred at 0 °C for 30 min. Afterward, (S)-bis[1-
phenylethyl]amine ((S,S)-7; 0.17 mmol, 39 μL) was added at 0 °C
and the solution was stirred and warmed to room temperature for 4 h.
In a second flame-dried Schlenk, compound (R)-8d (0.17 mmol, 106
mg) was placed and dried by dissolution in dry toluene (1 mL) and
evaporation of the resulting solution under vacuum (two times). Then,
the resulting dried (R)-8d was dissolved in dry and degassed THF (1
mL) and transferred by cannula to the first Schlenk flask at 0 °C. After
it was stirred at room temperature overnight (12 h), the reaction
mixture was quenched by adding dichloromethane (10 mL) followed
by brine (20 mL). After extraction, the organic phase was dried over
Na2SO4 and evaporated under vacuum. The solid residue was purified
1
g, 13% overall yield over four steps). H NMR (300 MHz, CDCl3): δ
0.89 (s, 6H), 1.93 (m, 2H), 3.06 (d, 2H, J = 6.9), 4.64 (m, 2H), 4.82
5596
dx.doi.org/10.1021/om4009058 | Organometallics 2013, 32, 5589−5600

Organometallics
Article
(bs, 1H), 5.06 (m, 3H), 7.35 (m, 5H).13C NMR (75 MHz, CDCl3): δ
24.7, 35.4, 39.1, 50.5, 66.8, 73.9, 85.8, 128.2, 128.3, 128.6, 136.7, 156.8,
209.8 (CO). HMRS (ESI): m/z calcd for C16H22NO2 260.16451
[MH+], found 260.16308.
AUTHOR INFORMATION
Corresponding Authors
*C.M.: e-mail, christophe.michon@ensc-lille.fr; fax, +33-
320436585.
*F.A.-N.: e-mail, francine.agbossou@ensc-lille.fr.
Notes
The authors declare no competing financial interest.
■
Benzyl 4,4-Dimethyl-2-vinylpyrrolidine-1-carboxylate (2g).
This compound was isolated after flash chromatography with
petroleum ether/ethyl acetate (8/2), Rf = 0.7, as a colorless oil
1
(quantitative). H NMR (300 MHz, CDCl3): δ 1.02 (s, 3H), 1.09 (s,
3H), 1.53 (m, 1H), 1.91 (dd, 1H, J = 8.1 Hz), 3.11 (d, 1H, J = 11.1
Hz), 3.45 (dd, 1H, J = 12.3 Hz), 4.35 (m, 1H), 5.12 (m, 4H), 5.81 (m,
1H), 7.35 (m, 5H). 13C NMR (75 MHz, CDCl3) as a mixture of 2
rotamers: δ [26.3, 26.5], [37.2, 37.7], [46.4, 47.3], [59.5, 59.6], 60.1,
66.7, [114.2, 114.7], 127.8 (4CAr), 128.5 (1CAr), 137.0, [139.3, 140.0],
[155.2, 155.6] (CO). HRMS (ESI): m/z calcd for C16H22NO2
260.16451 [MH+], found 260.16298. The enantiomeric excess (ee)
was measured by HPLC using Regis (S,S)-Whelk 01 CSP, at 25 °C,
with (90/10) n-hexane/iPrOH, 1 mL/min, λ 220 nm, tR(minor) =
17.0 min and tR(major) = 25.6 min. The ee was too low to measure a
ACKNOWLEDGMENTS
This work was financed by the French National Research
Agency with project ANR-09-BLAN-0032-02 (with a Ph.D.
fellowship to F.M.). The French “Ministere de la Recherche et
̀
des Nouvelles Technologies” is gratefully acknowledged for a
Ph.D. fellowship to M.-A.A.Support from the CNRS is warmly
■
acknowledged. Partial funding from Reg
with “Projet Prim: Etat-Region” and “Fonds Europee
Developpement Regional (FEDER)” is also appreciated. Mrs.
C. Meliet (UCCS) is thanked for elemental analyses on organic
́
ion Nord-Pas de Calais
́
́
n de
20
́
́
[α]D value.
((4R,5R)-1,3-Bis(2-methoxyphenyl)-4,5-diphenylimidazolin-
2-ylidene)gold Trichloride (4). This new compound was prepared
by following a related procedure.31 In a flame-dried Schlenk tube were
placed and dried a stirring bar, Au(I) complex 3 (67 mg, 0.1 mmol),
and iodobenzene dichloride (55 mg, 0.15 mmol). Under nitrogen,
acetonitrile (3 mL) was added and the reaction mixture was stirred
overnight (ca. 12 h) at room temperature. Diethyl ether was then
added to precipitate a solid which was further washed with petroleum
ether. After recrystallization (dichloromethane/petroleum ether) and
drying under vacuum, compound 4 was obtained as a yellow solid (50
́
samples. Mrs. C. Delabre (UCCS) is thanked for assistance
with GC and HPLC analyses. Mrs. N. Duhal (CUMA) is
thanked for HRMS analyses.
ABBREVIATIONS
■
TLC, thin-layer chromatography; GC, gas chromatography;
HPLC, high-pressure chromatography; CSP, chiral stationary
phase; NMR, nuclear magnetic resonance; HRMS, high-
resolution mass spectroscopy; ESI, electrospray ionization;
THF, tetrahydrofuran; TRIP, 3,3′-bis(2,4,6-triisopropylphen-
yl)-1,1′-binaphthyl-2,2′-diyl hydrogenphosphate; BARF,
tetrakis[3,5-bis(trifluoromethyl)phenyl]borate; PNB, p-nitro-
benzoate; CBz, benzylcarbamate; Ts, tosyl; Bn, benzyl; Boc,
tert-butyl carboxylate; NTf, trifluoromethaneimidate; IPr, 1,3-
bis(2,6-diisopropylphenyl)-1,3-dihydro-2H-imidazol-2-ylidene
1
mg, 0.07 mmol, 68%). H NMR (300 MHz, CDCl3): δ 4.00 (s, 6H),
5.49 (s, 2H), 6.95 (m, 4H), 7.35 (m, 4H), 7.47 (m, 10H). 13C NMR
(75 MHz, CDCl3): δ 56.5 (2CH3), 76.2 (2CH), 112.6 (CHAr), 113.7
(CHAr), 121.3 (CHAr), 124.8 (C), 125.7 (C), 127.4 (CHAr), 129.6
(CHAr), 130.1 (CHAr), 130.7 (CHAr), 131.7 (CHAr), 136.9 (C), 154.3
(C), 170.0 (CAu). [α]D20 = +179° (CH2Cl2, c = 0.2 g/100 mL). HRMS
(ESI+): m/z calcd for C29H27N2O2AuCl3 [MH+] 737.0798, found
737.0600. Anal. Calcd for (C29H26AuCl3N2O2 + CH2Cl2): C, 43.79; H,
3.43; N, 3.40. Found: C, 43.26; H, 3.28; N, 3.44.
REFERENCES
■
((4S,5S)-1,3-Dibenzhydryl-4,5-diphenylimidazolin-2-
ylidene)gold(III) Trichloride (6). This compound was prepared by
following a related procedure.31 In a flame-dried Schlenk tube were
placed and dried a stirring bar, Au(I) complex 5 (100 mg, 0.13 mmol),
and iodobenzene dichloride (70 mg, 0.19 mmol). Under nitrogen,
acetonitrile (3 mL) was added and the reaction mixture was stirred
overnight (ca. 12 h) at room temperature. Diethyl ether was then
added to precipitate a solid which was further washed with petroleum
ether. After recrystallization (dichloromethane/petroleum ether) and
drying under vacuum, compound 6 was obtained as a yellow solid (79
(1) (a) Brunet, J. J.; Neibecker, D. In Catalytic Heterofunctionalization
from Hydroamination to Hydrozirconation; Togni, A., Grutzmacher, H.,
Eds.; Wiley-VCH: Weinheim, Germany, 2001; pp 10−20. (b) Doye, S.
In Science of Synthesis; Enders, D., Schaumann, E., Eds.; Thieme:
Stuttgart, Germany, 2009; Vol. 40a, pp 241−304. (c) Hannedouche,
J.; Schulz, E. Chem. Eur. J. 2013, 19, 4972−4985. (d) Dub, P. A.; Poli,
R. J. Am. Chem. Soc. 2010, 132, 13799−13812. (e) Dzhemilev, U. M.;
Tolstikov, G. A.; Khusnutdinov, R. I. Russ. J. Org. Chem. 2009, 45,
957−987. (f) Chemler, S. R. Org. Biomol. Chem. 2009, 7, 3009−3019.
(g) Mueller, T. E.; Hultzsch, K. C.; Yus, M.; Foubelo, F.; Tada, M.
Chem. Rev. 2008, 108, 3795−3892. (h) Aillaud, I.; Collin, J.;
Hannedouche, J.; Schulz, E. Dalton Trans. 2007, 5105−5118.
(i) Hultzsch, K. C. Adv. Synth. Catal. 2005, 347, 367−391.
(j) Odom, A. L. Dalton Trans. 2005, 225−233. (k) Bytschkov, I.;
1
mg, 0.09 mmol, 73%). H NMR (300 MHz, CDCl3): δ 4.76 (s, 2H),
6.65 (s, 2H), 7.05 (m, HAr), 7.36 (m, HAr). 13C NMR (75 MHz,
CDCl3): δ 68.5 (2CH), 74.5 (2CH), 129.9 (4CHAr), 129.6 (4CHAr),
129.3 (4CHAr), 129.2 (5CHAr), 129.1 (3CHAr), 128.5 (2CHAr), 128.3
(4CHAr), 126.0 (4CHAr), 135.1 (2C), 137.6, 138.2 (4C), 171.6 (CAu).
[α]D20 = −14 (CH2Cl2, 0.2 g/100 mL). HRMS (ESI+): m/z calcd for
C41H35AuCl3N2 [MH+] 857.1526, found 857.1995. Anal. Calcd for
(C41H34AuCl3N2 + 1/2 CH2Cl2): C, 55.35; H, 3.92; N, 3,11. Found: C,
54.94; H, 3.90; N, 3.14.
Doye, S. Eur. J. Org. Chem. 2003, 935−946. (l) Roesky, P. W.; Muller,
̈
T. E. Angew. Chem., Int. Ed. 2003, 42, 2708−2710. (m) Muller, T. E.;
̈
Beller, M. Chem. Rev. 1998, 98, 675−703.
(2) For examples of asymmetric intramolecular hydroaminations with
lanthanide complexes, see: (a) Giardello, M. A.; Conticello, V. P.;
Brard, L.; Gagne, M. R.; Marks, T. J. J. Am. Chem. Soc. 1994, 116,
10241−10254. (b) Hong, S.; Tian, S.; Metz, M. V.; Marks, T. J. J. Am.
Chem. Soc. 2003, 125, 14768−14783. (c) Kim, J. Y.; Livinghouse, T.
Org. Lett. 2005, 7, 1737−1739. (d) Collin, J.; Daran, J.; Jacquet, O.;
Schulz, E.; Trifonov, A. Chem. Eur. J. 2005, 11, 3455−3462.
(e) Riegert, D.; Collin, J.; Meddour, A.; Schulz, E.; Trifonov, A. J.
Org. Chem. 2006, 71, 2514−2517. (f) Gribkov, D. V.; Hultzsch, K. C.;
Hampel, F. J. Am. Chem. Soc. 2006, 128, 3748−3759. (g) Chapurina,
Y.; Hannedouche, J.; Collin, J.; Guillot, R.; Schulz, E.; Trifonov, A.
Chem. Commun. 2010, 46, 6918−6920. (h) Reznichenko, A. L.;
Nguyen, H. P.; Hultzsch, K. C. Angew. Chem., Int. Ed. 2010, 49, 8984−
ASSOCIATED CONTENT
■
S
* Supporting Information
Text, figures, and tables giving additional data, experimental
procedures, and characterizations for other compounds, 1H and
13C NMR spectra of all final products (new or reported),
HRMS spectra of new compounds, and HPLC analyses. This
material is available free of charge via the Internet at http://
pubs.acs.org.
5597
dx.doi.org/10.1021/om4009058 | Organometallics 2013, 32, 5589−5600

Organometallics
Article
8987. (i) Chapurina, Y.; Ibrahim, H.; Guillot, R.; Kolodziej, E.; Collin,
J.; Trifonov, A.; Schulz, E.; Hannedouche, J. J. Org. Chem. 2011, 76,
10163−10172. (j) Manna, K.; Kruse, M. L.; Sadow, A. D. ACS Catal.
2011, 1, 1637−1642. (k) Benndorf, P.; Jenter, J.; Zielke, L.; Roesky, P.
W. Chem. Commun. 2011, 47, 2574−2576. (l) Zhang, Y.; Yao, W.; Li,
He; Mu, Y. Organometallics 2012, 31, 4670−4679. (m) Reznichenko,
A. L.; Hultzsch, K. C. Organometallics 2013, 32, 1394−1408.
Shibata, T. Org. Biomol. Chem. 2012, 10, 3815−3818. (i) Sevov, C. S.;
Zhou, J.; Hartwig, J. F. J. Am. Chem. Soc. 2012, 134, 11960−11963.
(j) Pan, S.; Endo, K.; Shibata, T. Org. Lett. 2012, 14, 780−783.
(6) Reviews on gold catalysis with C−C multiple bond substrates:
(a) Hashmi, A. S. K.; Buehrle, M. Aldrichimica Acta 2010, 43, 27−33.
(b) Widenhoefer, R. A. Chem. Eur. J. 2008, 14, 5382−5391. (c) Gorin,
D. J.; Sherry, B. D.; Toste, F. D. Chem. Rev. 2008, 108, 3351−3378.
(d) Hashmi, A. S. K. Chem. Rev. 2007, 107, 3180−3211.
(e) Widenhoefer, R. A.; Han, X. Eur. J. Org. Chem. 2006, 4555−4563.
(7) Examples on gold catalysis with alkynes: (a) Patil, N. T.; Singh,
V. J. Organomet. Chem. 2011, 696, 419−432. (b) Severin, R.; Doye, S.
Chem. Soc. Rev. 2007, 36, 1407−1420.
(3) For examples of asymmetric intramolecular hydroamination with
group 4 complexes, see: (a) Gribkov, D. V.; Hultzsch, K. C. Angew.
Chem., Int. Ed. 2004, 43, 5542−5546. (b) Knight, P. D.; Munslow, I.;
O’Shaughnessy, P. N.; Scott, P. Chem. Commun. 2004, 894−895.
(c) Bexrud, J. A.; Beard, J. D.; Leitch, D. C.; Schafer, L. L. Org. Lett.
2005, 7, 1959−1962. (d) Kim, H.; Lee, P. H.; Livinghouse, T. Chem.
(8) Examples of gold-catalyzed hydroamination of alkenes:
(a) Kojima, M.; Mikami, K. Synlett 2012, 23, 57−61. (b) Giner, X.;
Commun. 2005, 5205−5206. (e) Muller, C.; Loos, C.; Schulenberg,
̈
N.; Doye, S. Eur. J. Org. Chem. 2006, 2499−2503. (f) Watson, D. A.;
Chiu, M.; Bergman, R. G. Organometallics 2006, 25, 4731−4733.
(g) Wood, M. C.; Leitch, D. C.; Yeung, C. S.; Kozak, J. A.; Schafer, L.
L. Angew. Chem., Int. Ed. 2007, 46, 354−358. (h) Gott, A. L.; Clarke,
A. J.; Clarkson, G. J.; Scott, P. Organometallics 2007, 26, 1729−1737.
(i) Gott, A. L.; Clarke, A. J.; Clarkson, G. J.; Scott, P. Chem. Commun.
2008, 1422−1424. (j) Zi, G.; Liu, X.; Xiang, L.; Song, H.
Organometallics 2009, 28, 1127−1137. (k) Zi, G.; Zhang, F.; Xiang,
L.; Chen, Y.; Fang, W.; Song, H. Dalton Trans. 2010, 39, 4048−4061.
(l) Reznichenko, A. L.; Hultzsch, K. C. Organometallics 2010, 29, 24−
27. (m) Manna, K.; Xu, S.; Sadow, A. D. Angew. Chem., Int. Ed. 2011,
50, 1865−1868. (n) Manna, K.; Everett, W. C.; Schoendorff, G.;
Ellern, A.; Windus, T. L.; Sadow, A. D. J. Am. Chem. Soc. 2013, 135,
7235−7250.
́ ́ ́
Najera, C.; Kovacs, G.; Lledos, A.; Ujaque, G. Adv. Synth. Catal. 2011,
353, 3451−3466. (c) Kitahara, H.; Sakurai, H. J. Organomet. Chem.
2010, 696, 442−449. (d) Hidehiro, S.; Sakurai, H. Chem. Lett. 2010,
39, 46−48. (e) Iglesias, A.; Muniz, K. Chem. Eur. J. 2009, 15, 10563−
10569. (f) Zhang, Z.; Lee, S. D.; Widenhoefer, R. A. J. Am. Chem. Soc.
2009, 131, 5372−5373. (g) Yeh, M. C. P.; Pai, H. F.; Lin, Z. J.; Lee, B.
R. Tetrahedron 2009, 65, 4789−4794. (h) Bender, C. F.; Widenhoefer,
R. A. Chem. Commun. 2008, 2741−2743. (i) Giner, X.; Naj
́
era, C. Org.
, J. P.;
Lett. 2008, 10, 2919−2922. (j) Leseurre, L.; Toullec, P. Y.; Genet
̂
Michelet, V. Org. Lett. 2007, 9, 4049−4052. (k) Shi, M.; Liu, L. P.;
Tang, J. Org. Lett. 2006, 8, 4043−4046. (l) Zhang, J.; Yang, C. G.; He,
C. J. Am. Chem. Soc. 2006, 128, 1798−1799. (m) Brouwer, C.; He, C.
Angew. Chem., Int. Ed. 2006, 45, 1744−1747. (n) Liu, X. Y.; Li, C. H.;
Che, C. M. Org. Lett. 2006, 8, 2707−2710. (o) Bender, C. F.;
Widenhoefer, R. A. Chem. Commun. 2006, 4143−4144.
(4) For examples of asymmetric intramolecular hydroamination with
main-group metals, see: (a) Crimmin, M. R.; Casely, I. J.; Hill, M. S. J.
Am. Chem. Soc. 2005, 127, 2042−2043. (b) Martinez, P. H.; Hultzsch,
K. C.; Hampel, F. Chem. Commun. 2006, 2221−2223. (c) Ogata, T.;
Ujihara, A.; Tsuchida, S.; Shimizu, T.; Kaneshige, A.; Tomioka, K.
Tetrahedron Lett. 2007, 48, 6648−6650. (d) Datta, S.; Roesky, P. W.;
Blechert, S. Organometallics 2007, 26, 4392−4394. (e) Buch, F.;
Harder, S. Z. Naturforsch. 2008, 63b, 169−177. (f) Datta, S.; Gamer,
M. T.; Roesky, P. W. Organometallics 2008, 27, 1207−1213.
(g) Barrett, A. G. M.; Crimmin, M. R.; Hill, M. S.; Hitchcock, P. B.;
(9) Examples of gold-catalyzed hydroamination of allenes: (a) Butler,
K. L.; Tragni, M.; Widenhoefer, R. A. Angew. Chem., Int. Ed. 2012, 51,
5175−5178. (b) Rodríguez, L. I.; Roth, T.; Fillol, J. L.; Wadepohl, H.;
Gade, L. H. Chem. Eur. J. 2012, 18, 3721−3728. (c) Kim, J. H.; Park, S.
W.; Park, S. R.; Lee, S. Y.; Kang, E. J. Chem. Asian J. 2011, 6, 1982−
1986. (d) Kinjo, R.; Donnadieu, B.; Bertrand, G. Angew. Chem., Int. Ed.
2011, 50, 5560−5563. (e) Hashmi, A. S. K.; Schuster, A. M.; Litters,
S.; Rominger, F.; Pernpointner, M. Chem. Eur. J. 2011, 17, 5661−5667.
(f) Li, H.; Lee, S. D.; Widenhoefer, R. A. J. Organomet. Chem. 2011,
696, 316−320. (g) LaLonde, R. L.; Wang, Z. J.; Mba, M.; Lackner, A.
D.; Toste, F. D. Angew. Chem., Int. Ed. 2010, 49, 598−601. (h) Wang,
Z. J.; Benitez, D.; Tkatchouk, E.; Goddard, W. A., III; Toste, F. D. J.
Am. Chem. Soc. 2010, 132, 13064−13071. (i) Bartolome, C.; Garcia-
Cuadrado, D.; Ramiro, Z.; Espinet, P. Organometallics 2010, 29, 3589−
3592. (j) Hill, A. W.; Mark, R. J.; Kimber, M. C. J. Org. Chem. 2010,
75, 5406−5409. (k) Duncan, A. N.; Widenhoefer, R. A. Synlett 2010,
419−422. (l) Aikawa, K.; Kojima, M.; Mikami, K. Angew. Chem., Int.
Ed. 2009, 48, 6073−6077. (m) Zeng, X.; Soleilhavoup, M.; Bertrand,
G. Org. Lett. 2009, 11, 3166−3169. (n) Manzo, A. M.; Perboni, A. D.;
Broggini, G.; Rigamonti, M. Tetrahedron Lett. 2009, 50, 4696−4699.
(o) Zeng, X.; Frey, G. D.; Kousar, S.; Bertrand, G. Chem. Eur. J. 2009,
15, 3056−3060. (p) Nishina, N.; Yamamoto, Y. Tetrahedron 2009, 65,
1799−1808. (q) Lavallo, V.; Frey, G. D.; Donnadieu, B.; Soleihavoup,
M.; Bertrand, G. Angew. Chem., Int. Ed. 2008, 47, 5224−5228.
(r) Nishina, N.; Yamamoto, Y. Tetrahedron Lett. 2008, 49, 4908−4911.
(s) Kinder, R. E.; Zhang, Z.; Widenhoefer, R. A. Org. Lett. 2008, 10,
3157−3159. (t) Zhang, Z.; Bender, C. F.; Widenhoefer, R. A. J. Am.
Chem. Soc. 2007, 129, 14148−14149. (u) Lalonde, G. L.; Sherry, B. D.;
Kang, E. J.; Toste, F. D. J. Am. Chem. Soc. 2007, 129, 2452−2453.
(v) Hamilton, G. L.; Kang, E. J.; Mba, M.; Toste, F. D. Science 2007,
317, 496−499. (w) Nishina, N.; Yamamoto, Y. Synlett 2007, 1767−
1770. (x) Zhang, Z.; Bender, C. F.; Widenhoefer, R. A. Org. Lett. 2007,
9, 2887−2889. (y) Nishina, N.; Yamamoto, Y. Angew. Chem., Int. Ed.
2006, 45, 3314−3317. (z) Zhang, Z.; Liu, C.; Kinder, R. E.; Han, X.;
Quian, H.; Widenhoefer, R. A. J. Am. Chem. Soc. 2006, 128, 9066−
9073.
Kociok-Kohn, C.; Procopiou, P. A. Inorg. Chem. 2008, 47, 7366−7376.
̈
(h) Arrowsmith, M.; Hill, M. S.; Kociok-Kohn, G. Organometallics
̈
2009, 28, 1730−1738. (i) Horrillo-Martínez, P.; Hultzsch, K. C.
Tetrahedron Lett. 2009, 50, 2054−2056. (j) Crimmin, M. R.;
Arrowsmith, M.; Barrett, A. G. M.; Casely, I. J.; Hill, M. S.;
Procopiou, P. A. J. Am. Chem. Soc. 2009, 131, 9670−9685. (k) Zhang,
X.; Emge, T. J.; Hultzsch, K. C. Organometallics 2010, 29, 5871−5877.
(l) Deschamp, J.; Olier, C.; Schulz, E.; Guillot, R.; Hannedouche, J.;
Collin, J. Adv. Synth. Catal. 2010, 352, 2171−2176. (m) Deschamp, J.;
Collin, J.; Hannedouche, J.; Schulz, E. Eur. J. Org. Chem. 2011, 3329−
3338. (n) Wixey, J. S.; Ward, B. D. Chem. Commun. 2011, 47, 5449−
5451. (o) Wixey, J. S.; Ward, B. D. Dalton Trans. 2011, 40, 7693−
7696. (p) Jenter, J.; Koppe, R.; Roesky, P. W. Organometallics 2011,
̈
30, 1404−1413. (q) Neal, S. R.; Ellern, A.; Sadow, A. D. J. Organomet.
Chem. 2011, 696, 228−234. (r) Zhang, X.; Emge, T. J.; Hultzsch, K. C.
Angew. Chem., Int. Ed. 2012, 51, 394−398. (s) Brinkmann, C.; Barrett,
A. G. M.; Hill, M. S.; Procopiu, P. A. J. Am. Chem. Soc. 2012, 134,
2193−2207. (t) Nixon, T. D.; Ward, B. D. Chem. Commun. 2012, 48,
11790−11792.
(5) For examples of asymmetric intramolecular hydroamination with
late transition metals, see: (a) Lutete, L. M.; Kadota, I.; Yamamoto, Y.
J. Am. Chem. Soc. 2004, 126, 1622−1623. (b) Patil, N. T.; Lutete, L.
M.; Wu, H.; Pahadi, N. K.; Gridnev, I. D.; Yamamoto, Y. J. Org. Chem.
2006, 71, 4270−4279. (c) Shen, X.; Buchwald, S. L. Angew. Chem., Int.
Ed. 2010, 49, 564−567. (d) Turnpenny, B. W.; Hyman, K. L.;
Chemler, S. R. Organometallics 2012, 31, 7819−7822. For examples of
asymmetric intermolecular hydroaminations with late transition
metals, see: (e) Dorta, R.; Egli, P.; Zurcher, F.; Togni, A. J. Am.
Chem. Soc. 1997, 119, 10857−10858. (f) Fadini, L.; Togni, A. Chem.
Commun. 2003, 30−31. (g) Zhou, J.; Hartwig, J. F. J. Am. Chem. Soc.
2008, 130, 12220−12221. (h) Otsuka, M.; Yokoyama, H.; Endo, K.;
(10) Examples of gold-catalyzed hydroamination of dienes:
(a) Shapiro, N. D.; Rauniyar, V.; Halmiton, G. L.; Wu, J.; Toste, F.;
D.. Nat. Chem. 2011, 470, 245−250. (b) Krossing, I. Angew. Chem., Int.
Ed. 2011, 50, 11576−11578. (c) Kanno, O.; Kuriyama, W.; Wang, J.
5598
dx.doi.org/10.1021/om4009058 | Organometallics 2013, 32, 5589−5600

Organometallics
Article
Z.; Toste, F. D. Angew. Chem., Int. Ed. 2011, 50, 9919−9922.
(d) Sanguramath, R. A.; Rajashekharaya, A.; Hooper, T. N.; Butts, C.
P.; Green, M.; McGrady, J. E.; Russel, C. E. Angew. Chem., Int. Ed.
2011, 50, 7592−7595. (e) Kothandaraman, P.; Huang, C. H.; Susanti,
D.; Rao, W. D.; Chan, P. W. H. Chem. Eur. J. 2011, 17, 10081−10088.
(f) Ramachary, D. B.; Narayana, V. V. Eur. J. Org. Chem. 2011, 3514−
Wang, W.; Zhang, Z.; Shi, M. Tetrahedron: Asymmetry 2011, 22,
2029−2038. (l) Selim, K. B.; Nakanishi, H.; Matsumoto, Y.;
Yamamoto, Y.; Yamada, K.; Tomioka, K. J. Org. Chem. 2011, 76,
1398−1408. (m) Pradal, A.; Toullec, P. Y.; Michelet, V. Synthesis 2011,
1501−1514. (n) Wang, Y. M.; Kuzniewski, C. N.; Rauniyar, V.;
Hoong, C.; Toste, F. D. J. Am. Chem. Soc. 2011, 133, 12972−12975.
(o) Yamada, K.; Matsumoto, Y.; Selim, K. B.; Yamamoto, Y.; Tomioka,
K. Tetrahedron 2012, 68, 4159−4165. (p) Handa, S.; Slaughter, L. M.
Angew. Chem., Int. Ed. 2012, 51, 2912−2915. (q) Francos, J.; Grande-
3522. (g) Giner, X.; Trillo, P.; Naj
696, 357−361. (h) Yeh, M. C. P.; Pai, H. F.; Lin, Z. J.; Lee, B. R.
era, C. Org. Lett.
́
era, C. J. Organomet. Chem. 2010,
Tetrahedron 2009, 65, 4789−4794. (i) Giner, X.; Naj
́
2008, 10, 2919−2922. (j) Brouwer, C.; He, C. Angew. Chem., Int. Ed.
2006, 45, 1744−1747.
́
Carmona, F.; Faustino, H.; Iglesias-Siguenza, J.; Dıez, E.; Alonso, I.;
̈
Fernan
́ ́
dez, R.; Lassaletta, J. M.; Lopez, F.; Mascarenas, J. L. J. Am.
̃
(11) Teller, H.; Corbet, M.; Mantilli, L.; Gopakumar, G.; Goddard,
Chem. Soc. 2012, 134, 14322−14325.
R.; Thiel, W.; Furstner, A. J. Am. Chem. Soc. 2012, 134, 15331−15342.
̈
(19) Gold aminocarbene catalyst for the asymmetric intramolecular
hydroamination of allenes: Liu, L.; Wang, F.; Wang, W.; Zhao, M.; Shi,
M. Beilstein J. Org. Chem. 2011, 7, 555−564.
(12) Carvajal, M. A.; Novoa, J. J.; Alvarez, S. J. Am. Chem. Soc. 2004,
126, 1465−1477.
(13) (a) Gimeno, M. C.; Laguna, A. Chem. Rev. 1997, 97, 511−522.
(b) Ito, H.; Saito, T.; Miyahara, T.; Zhong, C.; Sawamura, M.
Organometallics 2009, 28, 4829−4840. (c) Ito, H.; Takagi, K.;
Miyahara, T.; Sawamura, M. Org. Lett. 2005, 7, 3001−3004.
(14) (a) Li, Z.; Zhang, J.; Brouwer, C.; Yang, C. G.; Reich, N. W.; He,
C. Org. Lett. 2006, 8, 4175−4178. (b) Shi, W. J.; Liu, Y.; Butti, P.;
Togni, A. Adv. Synth. Catal. 2007, 349, 1619−1623.
(20) Johnson, M. W.; Shevick, S. L.; Toste, F. D.; Bergman, R. G.
Chem. Sci. 2013, 4, 1023−1027.
(21) (a) Kovac
130, 853−864. (b) Kovac
2010, 29, 5919−5926.
́
s, G.; Ujaque, G.; Lledos
́
, A. J. Am. Chem. Soc. 2008,
́
s, G.; Lledos
́
, A.; Ujaque, G. Organometallics
(22) LaLonde, R. L.; Brenzovich, W. E.; Benitez, D.; Tkatchouk, E.;
Kelley, K.; Goddard, W. A., III; Toste, F. D. Chem. Sci. 2010, 1, 226−
233.
(15) (a) Zhang, Z.; Liu, C.; Kinder, R. E.; Han, X.; Quian, H.;
Widenhoefer, R. A. J. Am. Chem. Soc. 2006, 128, 9066−9073. (b) Patil,
N. T.; Lutete, L. M.; Nishina, N.; Yamamoto, Y. Tetrahedron Lett.
2006, 47, 4749−4751. (c) Nishina, N.; Yamamoto, Y. Angew. Chem.,
Int. Ed. 2006, 45, 3314−3317. (d) Nishina, N.; Yamamoto, Y. Synlett
2007, 1767−1770. (e) Nishina, N.; Yamamoto, Y. Tetrahedron Lett.
2008, 49, 4908−4911. (f) Nishina, N.; Yamamoto, Y. Tetrahedron
2009, 65, 1799−1808. (g) Lavallo, V.; Frey, G. D.; Donnadieu, B.;
Soleilhavoup, M.; Bertrand, G. Angew. Chem., Int. Ed. 2008, 47, 5224−
5228. (h) Zeng, X.; Soleilhavoup, M.; Bertrand, G. Org. Lett. 2009, 11,
3166−3169. (i) Kinjo, R.; Donnadieu, B.; Bertrand, G. Angew. Chem.,
Int. Ed. 2011, 50, 5560−5563. (j) Patil, P. T. Chem. Asian. J. 2012, 7,
2186−2194.
́
(23) (a) Brown, T. J.; Weber, D.; Gagne, M.; Widenhoefer, R. A. J.
Am. Chem. Soc. 2012, 134, 9134−9137. (b) Roth, K. E.; Blum, S. A.
Organometallics 2010, 29, 1712−1716. (c) Shi, Y.; Roth, K. E.;
Ramgren, S. D.; Blum, S. A. J. Am. Chem. Soc. 2009, 131, 18022−
18023.
̀
(24) Gandon, V.; Lemiere, G.; Hours, A.; Fensterbank, L.; Malacria,
M. Angew. Chem., Int. Ed. 2008, 47, 7534−7538.
(25) (a) Sallio, R.; Lebrun, S.; Schifano-Faux, N.; Goossens, J. F.;
Agbossou-Niedercorn, F.; Deniau, E.; Michon, C. Synlett 2013, 1785−
1790. (b) Medina, F.; Duhal, N.; Michon, C.; Agbossou-Niedercorn, F.
C. R. Chim. 2013, 16, 311−317. (c) Medina, F.; Michon, C.;
Agbossou-Niedercorn, F. Eur. J. Org. Chem. 2012, 6218−6227.
(d) Michon, C.; Medina, F.; Capet, F.; Roussel, P.; Agbossou-
Niedercorn, F. Adv. Synth. Catal. 2010, 352, 3293−3305. (e) Brunet, J.
J.; Neibecker, D.; Agbossou, F.; Radhey, S. S. J. Mol. Catal. 1994, 87,
223−230.
(16) Nguyen, B. N.; Adrio, L. A.; Barreiro, E. M.; Brazier, J. B.;
Haycock, P.; Hii, K. K.; Nachtegaal, M.; Newton, M. A.; Szalchetko, J.
Organometallics 2012, 31, 2395−2402.
(17) Phosphoramidite ligands in asymmetric gold catalysis:
(a) Munoz, M. P.; Adrio, J.; Carretero, J. C.; Echavarren, A. M.
̃
(26) (a) Matsumoto, Y.; Yamada, K. I.; Tomioka, K. J. Org. Chem.
2008, 73, 4578−4581. (b) Matsumoto, Y.; Selim, K. B.; Nakanishi, H.;
Yamada, K. I.; Yamamoto, Y.; Tomioka, K. Tetrahedron Lett. 2010, 51,
404−407. (c) Selim, K. B.; Matsumoto, Y.; Yamada, K.; Tomioka, K.
Angew. Chem., Int. Ed. 2009, 48, 8733−8735.
(27) Satyanarayana, T.; Abraham, S.; Kagan, H. B. Angew. Chem., Int.
Ed. 2009, 48, 456−494.
Organometallics 2005, 24, 1293−1300. (b) Alonso, I.; Trillo, B.; Lop
F.; Montserrat, S.; Ujaque, G.; Castedo, L.; Lledos, A.; Mascarenas, J.
L. J. Am. Chem. Soc. 2009, 131, 13020−13030. (c) Teller, H.; Flugge,
́
ez,
́
̃
̈
S.; Goddard, R.; Furstner, A. Angew. Chem., Int. Ed. 2010, 49, 1949−
̈
1953. (d) Gonzal
(e) Gonzalez, A. Z.; Benitex, D.; Tkatchouk, E.; Goddard, W. A.;
Toste, F. D. J. Am. Chem. Soc. 2011, 133, 5500−5507. (f) Alonso, I.;
Faustino, H.; Lopez, F.; Mascarenas, J. L. Angew. Chem., Int. Ed. 2011,
́
es, A. Z.; Toste, F. D. Org. Lett. 2010, 12, 200−203.
́
(28) (a) Xie, J. H.; Zhou, Q.; L.. Acc. Chem. Res. 2008, 41, 581−593.
(b) Ding, K.; Han, Z.; Wang, Z. Chem. Asian. J. 2009, 4, 32−41.
(c) Bajracharya, G. B.; Arai, M. A.; Koranne, P. S.; Suzuki, T.;
Takizawa, S.; Sasai, H. Bull. Chem. Soc. Jpn. 2009, 82, 285−302.
(29) Wang, D.; Cai, R.; Sharma, S.; Jirak, J.; Thummanapelli, S. K;
Akhmedov, N. G.; Zhang, H.; Liu, X.; Petersen, J. L.; Shi, X. J. Am.
Chem. Soc. 2012, 134, 9012−9019.
́
̃
50, 11496−11500. (g) Suarez-Pantiga, S.; Hernandez-Diaz, C.; Rubio,
E.; Gonzalez, J. M. Angew. Chem., Int. Ed. 2012, 51, 11552−11555.
́
(h) Faustino, H.; Alonso, I.; Mascarenas, J. L.; Lopez, F. Angew. Chem.,
̃
Int. Ed. 2013, 52, 6526−6530. (i) Li, G. H.; Zhou, W.; Li, X. X.; Bi, Q.
W.; Wang, Z.; Zhao, Z. G.; Hu, W. X.; Chen, Z. Chem. Commun. 2013,
49, 4770−4772.
(30) (a) Wu, T. R.; Shen, L.; Chong, J. M. Org. Lett. 2004, 6, 2701−
(18) Diaminocarbene ligands in asymmetric gold catalysis:
(a) Corberan, R.; Ramírez, J.; Poyatos, M.; Peris, E.; Fernandez, E.
Tetrahedron: Asymmetry 2006, 17, 1759−1762. (b) Matsumoto, Y.;
Tomioka, K. Tetrahedron Lett. 2006, 47, 5843−5846. (c) Matsumoto,
Y.; Yamada, K.; Tomioka, K. J. Org. Chem. 2008, 73, 4578−4581.
(d) Bongers, N.; Krause, N. Angew. Chem., Int. Ed. 2008, 47, 2178−
2181. (e) Selim, K. B.; Matsumoto, Y.; Yamada, K.; Tomioka, K.
Angew. Chem., Int. Ed. 2009, 48, 8733−8735. (f) Matsumoto, Y.; Selim,
K. B.; Nakanishi, H.; Yamada, K.; Yamamoto, Y.; Tomioka, K.
Tetrahedron Lett. 2010, 51, 404−407. (g) Sengupta, S.; Shi, X.
ChemCatChem 2010, 2, 609−619. (h) Bartolome, C.; García-
Cuadrado, D.; Ramiro, Z.; Espinet, P. Inorg. Chem. 2010, 49, 9758−
9764. (i) Wilckens, K.; Lentz, D.; Czekelius, C. Organometallics 2011,
30, 1287−1290. (j) Wang, W.; Yang, J.; Wang, F.; Shi, M.
Organometallics 2011, 30, 3859−3869. (k) Yang, J.; Zhang, R.;
2704. (b) Singh, R.; Czekelius, C.; Schrock, R. R.; Muller, P.; Hoveyda,
̈
A. H. Organometallics 2007, 26, 2528−2539. (c) Storer, R. I.; Carrera,
D. E.; Ni, Y.; MacMillan, D. W. C. J. Am. Chem. Soc. 2006, 128, 84−86.
(d) Zhang, Y. L.; Zhang, F.; Tang, W. J.; Wu, Q. L.; Fan, Q. H. Synlett
2006, 8, 1250−1254. (e) Mercier, A.; Urbaneja, X.; Yeo, W. C.;
Chaudhuri, P. D.; Cumming, G. R.; House, D.; Bernardinelli, G.;
Kundig, E. P. Chem. Eur. J. 2010, 16, 6285−6299. (f) Wipf, P.; Jung, J.
̈
K. J. Org. Chem. 2000, 65, 6319−6337.
(31) Gaillard, S.; Slawin, A. M. Z.; Bonura, A. T.; Stevens, E. D.;
Nolan, S. P. Organometallics 2010, 29, 394−402.
(32) Hooper, T. N.; Butts, C. P.; Green, M.; Haddow, M. F.;
McGrady, J. E.; Russel, C. A. Chem. Eur. J. 2009, 15, 12196−12200.
(33) (a) Buschmann, W. E.; Miller, J. S. Inorg. Synth. 2002, 33, 83−
84. (b) Yakelis, N. A.; Bergman, R. G. Organometallics 2005, 24,
5599
dx.doi.org/10.1021/om4009058 | Organometallics 2013, 32, 5589−5600

Organometallics
Article
3579−3581. (c) Brookhart, M.; Grant, B.; Volpe, A. F. Organometallics
1992, 11, 3920−3922.
(34) (a) Klussmann, M.; Ratjen, L.; Hoffmann, S.; Wakchaure, V.;
Goddard, R.; List, B. Synlett 2010, 2189−2192. (b) Hamilton, G. L.;
Kang, E. J.; Mba, M.; Toste, F. D. Science 2007, 317, 496−499.
(35) (a) Arbour, J. L.; Rzepa, H. S.; Contreras-Garcia, J.; Adrio, L. A.;
Barreiro, E. M.; Hii, K. K. Chem. Eur. J. 2012, 18, 11317−11324.
(b) Mukherjee, P.; Widenhoefer, R. A. Angew. Chem., Int. Ed. 2012, 51,
1405−1407.
5600
dx.doi.org/10.1021/om4009058 | Organometallics 2013, 32, 5589−5600