Stereospecific allyl-aryl coupling catalyzed by in situ generated palladium nanoparticles in water under ambient conditions

Article abstract of DOI:10.1002/adsc.201200704

A practical process for the stereospecific cross-coupling of secondary allylic carbonates with arylboronic acids has been developed. The reaction is catalyzed by in situ generated palladium nanoparticles (PdNPs) without any ligands and additional stabilizers in water under ambient conditions and furnishes the allyl-aryl coupling products in high isolated yields with high stereospecificities as well as excellent chemo-, regio- and E/Z-selectivities. The in situ generated PdNPs showed extraordinary catalytic activity (S/C up to 5000) even for the allyl-aryl coupling reactions of easily eliminated allylic carbonates under aqueous ambient conditions. The mechanism of the process has also been investigated.

Full text of DOI:10.1002/adsc.201200704

FULL PAPERS
DOI: 10.1002/adsc.201200704
Stereospecific Allyl–Aryl Coupling Catalyzed by in situ
Generated Palladium Nanoparticles in Water under Ambient
Conditions
Jingming Zhao,a Jiang Ye,a and Yong Jian Zhanga,*
a
School of Chemistry and Chemical Engineering, and Shanghai Key Laboratory of Electrical Insulation and Thermal
Aging, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, Peopleꢀs Republic of China
Fax : (+86)-21-5474-1297; e-mail: yjian@sjtu.edu.cn
Received: August 8, 2012; Revised: November 7, 2012; Published online: February 1, 2013
Supporting information for this article is available on the WWW under http://dx.doi.org/10.1002/adsc.201200704.
Abstract: A practical process for the stereospecific situ generated PdNPs showed extraordinary catalytic
cross-coupling of secondary allylic carbonates with activity (S/C up to 5000) even for the allyl–aryl cou-
arylboronic acids has been developed. The reaction pling reactions of easily eliminated allylic carbonates
is catalyzed by in situ generated palladium nanopar- under aqueous ambient conditions. The mechanism
ticles (PdNPs) without any ligands and additional of the process has also been investigated.
stabilizers in water under ambient conditions and
furnishes the allyl–aryl coupling products in high iso- Keywords: allyl–aryl coupling; asymmetric synthesis;
lated yields with high stereospecificities as well as ex- cross-coupling; palladium nanoparticles; stereospeci-
cellent chemo-, regio- and E/Z-selectivities. The in ficity
Introduction
Suzuki–Miyaura coupling of secondary allylic electro-
philes with arylboronic acids. The method also offered
The Suzuki–Miyaura coupling has emerged as one of a possibility to conduct the stereoselective allyl–aryl
À
the most versatile transformations for C C bond for- coupling through the stereospecific cross-coupling of
mation.[1] While the coupling reaction has most often chiral secondary allylic electrophiles.[10,11,12] Whereas
been applied to sp2-hybridized halides and pseudoha- the stereospecificity of the coupling reaction is largely
lides, significant progress toward extending the cou- affected by the ligand, and some issues, such as higher
pling method to secondary sp3-electrophiles has been catalyst loading, requirement of achiral ligand, and/or
achieved using Ni catalysts since the ground-breaking high reaction temperature, need to improve for prac-
work by Fu in 2004.[2,3] Pd is the primarily used cata- tical use of the process in asymmetric synthesis.
lyst for the cross-coupling reaction, and yet it is not
In recent years amelioration of the cross-coupling
effective for the coupling reaction of secondary alkyl reaction has been directed towards the more efficient,
electrophiles due to the high energy barrier of the ox- economic and greener techniques.[13] Since the first
idative addition.[4,5] In contrast, secondary allylic alco- report of ligand-free Pd-catalyzed Suzuki–Miyaura
hol derivatives are expected to be applicable as elec- coupling by Beletskaya,[14] simple Pd salts such as
trophiles for the coupling reaction because Pd can be PdCl2 or PdACTHNURTGNENG(U OAc)2 in the absence of phosphane li-
readily oxidized with allylic partners forming allylpal- gands are increasingly being used in Suzuki–Miyaura
ladium intermediates.[6] However, the protocols for aryl–aryl couplings.[15] The mechanism studies by
the coupling reaction of secondary and potentially Reetz and de Vries demonstrated that the Pd salts
enantiomerically enriched allylic electrophiles are sur- indeed decompose to give palladium nanoparticles
prisingly less explored, mainly due to the propensity (PdNPs) at high temperature, and the catalysis takes
for allylpalladium intermediates to undergo b-hydride place on the surface of PdNPs.[16] Indeed, PdNPs-cata-
elimination delivering the conjugated diene.[7] Never- lyzed cross-coupling reactions have recently attracted
theless, pioneering work by Uozumi and Hayashi,[8] as great attention due to their high catalytic activity and
well as the most recent efforts by Uozumi and the fact of allowing for ligand-free synthesis.[17] How-
Yamada,[9] Tian,[10] and our group,[11] respectively, ever, PdNPs are generally prepared by complicated
demonstrated the feasibility of the Pd-catalyzed processes and additional stabilizers are required in
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Table 1. Allyl–aryl coupling of allylic carbonate 1a with
phenylboronic acid (2a).[a]
order to prevent the formation of Pd black precipi-
tates, as well as the fact that the reactions typically
need to be performed at high temperature.[18]
Given that great efforts in the development of
greener process for Suzuki–Miyaura aryl–aryl cou-
plings, we recently questioned whether the stereospe-
cific allyl–aryl coupling could also be addressed with
PdNPs as catalyst without phosphane ligands using
chiral secondary allylic electrophiles. Indeed, chiral
secondary allylic alcohols are readily accessible by the
numerous approaches that have been reported for the
asymmetric synthesis of optically active secondary al-
lylic alcohols, such as the addition of vinyl-metal re-
agents to aldehydes,[19] ketone reduction,[20] allylic
substitution of primary allylic carbonates,[21] Sharpless
kinetic resolution,[22] and lipase resolution.[23] In this
paper, we report the successful execution of these
ideals and present a practical method for the stereo-
specific allyl–aryl coupling of secondary allylic carbo-
nates with arylboronic acids catalyzed by in situ gen-
erated PdNPs without any ligands and additional sta-
Entry
Ligand
Solvent
T [oC]/
t [h]
Conv.
[%][b]
Yield
[%][c]
1
2
3
4
5
6
PPh3
PPh3
–
–
–
–
THF/H2O[d]
THF/H2O[d]
THF/H2O[d]
H2O
THF
MeOH
50/24
25/4
25/4
25/4
25/4
25/4
100
0
33
100
16
50
87
–
–
99
–
–
[a]
Reaction conditions: PdACHTNUGTRNEUNG(OAc)2 (1 mol%), PPh3 (2 mol%)
1a (0.50 mmol), 2a (0.75 mmol), solvent (0.5 mL).
Determined by H NMR of the crude reaction mixture.
The yields are of isolated material.
Using 5 equiv. of water to 1a.
[b]
[c]
[d]
1
bilizers in water at ambient temperature. Although in the presence of 1 mol% of PdACTHNUTRGNE(UNG OAc)2 in water at
there are a few reports on asymmetric reactions cata- ambient temperature. Gratifyingly, the reaction fur-
lyzed by metal NPs with chiral ligands as stabilizers,[24] nished allyl–aryl coupling product 3a in quantitative
to the best of our knowledge, this is the first example yield with complete enantiospecificity with inversion
of a stereospecific reaction catalyzed by metal NPs. of the absolute configuration, and no E/Z isomeriza-
Furthermore, we have expanded the substrate scope tion and b-H elimination were observed (Scheme 1).
to more challenging secondary allylic carbonates with
Interestingly, we found that the reaction mixture
1-benzyl, allyl or carbonylmethyl groups, which are turned black after a few minutes. Based on general
largely unexplored allylic partners even for the allylic knowledge, if the Pd black forms in the early stage of
substitution reaction, coupling them with arylboronic the reaction, the reaction usually stops before full
acids to furnish allyl–aryl coupling products in high conversion. In order to recognize the real catalytic
yields with complete chemo- and regioselectivities.
species and mechanism, we tried to monitor the reac-
tion by transmission electron microscopy (TEM).
Firstly, the sample was made by mixing PdACHTUNGTRENNUNG(OAc)2
Results and Discussion
(5 mmol) and phenylboronic acid (0.75 mmol) in water
(0.5 mL) and the mixture was stirred for 5 min at am-
As in our previous report,[11] the coupling reaction of bient temperature. The TEM analysis indicated that
allylic carbonate 1a with phenylboronic acid (2a) pro- PdNPs were generated and dispersed well with an
ceeded well in the presence of PdACHTUNGTRNEUNG
(OAc)2 and PPh3 in average particle size of 2.6 nm[25] (Figure 1a). We also
wet THF at 508C giving coupling product 3a in 87% found that the reaction gave a trace amount of bi-
1
yield with excellent selectivities (Table 1, entry 1). phenyl as determined by H NMR. These results dem-
However, under otherwise identical conditions but at onstrated that PdACHTNUTRGNEUNG(OAc)2 was reduced to form PdNPs
ambient temperature, the reaction did not work at all by homo-coupling of phenylboronic acid,[26] and the
(entry 2). In contrast, the reaction proceeded in the PdNPs are likely stabilized by phenylboronic acid.[27]
absence of phosphane ligand giving the allyl–aryl cou- For further investigation of the catalytic behavior, the
pling product 3a in 33% conversion (entry 3). Surpris- standard coupling reaction of 1a with 2a in water was
ingly, with the replacement of wet THF solvent by monitored by TEM. Remarkably, the average particle
pure water, the substrates were completely converted
to the coupling product 3a in 99% isolated yield using
1 mol% of PdACHTUNGTRENNUNG(OAc)2 as a catalyst at ambient temper-
ature for 4 h (entry 4). Nevertheless, when the reac-
tions were carried out in organic solvents such as
THF and MeOH, low conversions were observed (en-
tries 5 and 6). Next, we examined the allyl–aryl cou-
pling reaction of enantiomerically enriched allylic car-
bonate (S)-1a (97% ee) with phenylboronic acid (2a) PdAHCTUNGTRENNUNG
Scheme 1. Stereospecific allyl–aryl coupling catalyzed by
(OAc)2 in water under ambient temperature.
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Stereospecific Allyl–Aryl Coupling Catalyzed by in situ Generated Palladium Nanoparticles in Water
Figure 2. Plot of the conversion and the average particle size
of PdNPs vs. reaction time for the coupling reaction of 1a
with 2a.
chiometric studies were performed by mixing PdNPs
in situ generated from PdACHTNUTRGNENG(U OAc)2 and phenylboronic
acid, and allylic carbonate 1a in CD3OD. However, by
1H NMR monitoring of the reaction, a p-allylpalladi-
um species was not observed, perhaps because the in-
termediate is very unstable.
With the mechanism insight in hand, the PdNPs-
catalyzed allyl–aryl coupling reaction was applied to
various combinations of chiral allylic carbonates 1a–
1d and arylboronic acids 2a–2i in water at ambient
temperature. As illustrated in Table 2, all of the reac-
tions gave allyl–aryl coupling products 3a–3k in high
yields with complete regioselectivities and excellent
enantiospecificities (95–100% es) with inversion of
the absolute configurations, and no E/Z isomeriza-
tions and b-H eliminations were observed. The reac-
tion can tolerate sterically hindered arylboronic acids
Figure 1. TEM image of PdNPs. a) A sample of PdNPs
formed by mixing of Pd(OAc)2 and phenylboronic acid (2a)
in water. b) A sample of PdNPs after full conversion of the
coupling reaction of 1a with 2a (2 h).
AHCTUNGTRENNUNG
size was reduced to 1.9 nm after the reaction had such as 2b and 2i to furnish the products in high
been carried out for 10 min[28] and the average size of yields and excellent selectivities. The reaction with ar-
PdNPs remained in the range of 1.9 to 2.1 nm until ylboronic acids containing electron-withdrawing
full conversion of the reaction after 2 h, and no Pd groups gave slightly lower yields in comparison with
black was observed (Figure 1b and Figure 2). The size those containing electron-donating groups (3c and 3d
decreases maybe due to the fact that Pd atoms leach vs. 3e, 3f and 3g). The reaction of aliphatic allylic car-
from Pd clusters during the oxidative addition to re- bonate 1d with phenylboronic acid (2a) provided cou-
lease active p-allylPd(II) species and that PdNPs are pling product 3l in moderate yield with complete
reaggregated after the reductive elimination.[29] In ad- regio- and E/Z selectivities and stereospecificity.
dition, in the kinetic study for the coupling reaction
In order to further examine the regioselectivity of
(Figure 2), the reaction showed extremely high cata- the coupling reaction, the reaction conditions were
lytic activity in initial stage giving 62% conversion in applied to the aliphatic allylic carbonates 1e and 1f
just 10 min. These results indicate that the highly re- (Scheme 2). The coupling reaction of the sterically
active leached Pd species might be the real catalytic less differentiated, 1-(2-phenyl)ethyl 3-methylallylic
species. In order to get more evidences for this hy- carbonate 1e with phenylboronic acid (2a) gave a mix-
1
pothesis, we tried to monitor the reaction by H NMR ture of the two regioisomers of 3m and 4a with a ratio
using D2O as a solvent, however, no peaks for the of 42:58 in 73% yield. The reaction of 1-(2-phenyl)-
starting material 1a, the coupling product 3a and any ethyl allylic carbonate 1f with 2a afforded linear
intermediates were observed because allylic carbon- product 4b as a major product. These results indicate
ate 1a and product 3a are not soluble in water. Stoi- that the regioselectivity of the allyl–aryl coupling re-
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Table 2. Stereospecific allyl–aryl coupling of allylic carbo-
nates with arylboronic acids catalyzed by in situ generated
PdNPs.[a]
Scheme 2. PdNPs-catalyzed allyl–aryl coupling of allylic car-
bonates 1e and 1f with 2a.
Scheme 3. Proposed reaction mechanism.
1a from the back side stereospecifically. The active Pd
species subsequently takes part in a transmatalation
with phenylboronic acid, and reductive elimination
occurs at the sterically less hindered side of the p-al-
lylpalladium complex to furnish the inversed allyl–
aryl coupling product (R)-3a with complete regiose-
lectivity and stereospecificity. The released Pd(0) spe-
cies is reaggregated to form PdNPs. Water plays a sig-
nificant role for the acceleration of the transmetala-
tion step.[1] The coupling reaction is likely to occur at
the interface of the organic substrate and water, the
released boronic acid monobutoxide dissolves in
water and plays a role for the stabilization of PdNPs.
The success of the highly selective allyl–aryl cou-
pling reaction catalyzed by in situ generated PdNPs in
[a]
Reaction conditions: PdACTHNUTRGNE(UNG OAc)2 (1 mol%), 1 (0.50 mmol),
2 (0.75 mmol), water (0.5 mL), 258C, 4 h. The yields are
of isolated material. The enantiomeric excesses were de-
termined by chiral HPLC analysis. The absolute configu-
rations were determined by comparing the sign of the op-
tical rotation with reported values.[10,11,30] Enantiospecific-
ity (es)=eeproduct/eesubstrate ꢂ100%. All of the reactions
gave coupling products with complete chemo-, regio- and
E/Z-selectivities.
action is controlled by the steric differences of the 1- water under ambient temperature prompted us to ex-
and 3-substituents of the allylic carbonates. amine the coupling reaction of more challenging sub-
Based on these studies, a mechanism and stereo- strates such as 1-benzyl-3-phenylallylic carbonate 1g,
chemical mode of the coupling reaction could be pro- which is a largely unexplored substrate even for the
posed as shown in Scheme 3. The active p-allylpalla- allylic substitution reaction. The main reason likely is
dium species is formed via leaching from PdNPs by that its p-allylpalladium complex greatly tends to un-
the oxidative addition to chiral allylic carbonate (S)- dergo b-hydride elimination to form highly conjugat-
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Stereospecific Allyl–Aryl Coupling Catalyzed by in situ Generated Palladium Nanoparticles in Water
Table 3. Allyl–aryl coupling of easily eliminated allylic car-
bonates with arylboronic acids catalyzed by in situ generated
PdNPs.[a]
Scheme 4. PdNPs-catalyzed chemo- and regioselective allyl–
aryl coupling of 1g with 2a.
ed 1,4-diphenyl-1,3-butadiene (5). As shown in
Scheme 4, with our previously reported reaction con-
ditions,[11] the reaction with Pd
ACHTNUGTRENUNG(OAc)2 and PPh3 in
wet THF at 508C for 24 h afforded the eliminated 1,3-
butadiene 5 as a major product as determined by
1H NMR of the crude reaction mixture. Remarkably,
the reaction of allylic carbonate 1g with phenylboron-
ic acid (2a) under our PdNPs-catalyzed reaction con-
ditions gave allyl–aryl coupling product 3o in 99%
isolated yield with complete regio- and E/Z-selectivi-
ties, and no 1,3-diene 5 was observed.
For further investigation on the scope of this type
of substrates for the coupling reaction, various sub-
strates were synthesized and applied to the allyl–aryl
coupling reaction. As shown in Table 3, the reaction
of allylic carbonates 1g–1j with 1-benzyl groups with
different substituents on the phenyl ring with phenyl-
boronic acid (2a) in the presence of 1 mol% of
[a]
Reaction conditions: PdACTHNUTRGNE(UNG OAc)2 (1 mol%), 1 (0.50 mmol),
2 (0.75 mmol), water (1.0 mL), 258C, 12 h.
The yields are of isolated material.
PdACHTUNGTRENNUNG(OAc)2 in water under ambient temperature for
12 h[31] proceeded with full conversion to the corre-
sponding allyl–aryl coupling products in quantitative
yields with complete chemo-, regio- and E/Z selectivi-
ties (entries 1–4). The reaction of 1-carbonylmethyl
allylic carbonates 1k and 1l, which also readily under-
go b-hydride elimination to form a,b,g,d-conjugated
carbonyl compounds, still worked well giving allyl–
aryl coupling products in high yields with excellent
chemo-, regio- and E/Z-selectivities[32] (entries 5 and
[b]
[c]
The reaction was carried out in the presence of 0.1 mol%
of PdACHTUGNTNER(NUNG OAc)2 in water (0.5M) at ambient temperature for
24 h.
[d]
The reaction was carried out in the presence of
0.02 mol% of Pd(OAc)2 in water (0.5M) at ambient tem-
perature for 72 h.
AHCTUNGTRENNUNG
6). Finally, we examined the coupling reaction of 1- steric and electronic properties giving allyl–aryl cou-
allyl-3-phenylallylic carbonate 1m with arylboronic pling products 3v–3y in high yields with complete
acids. Under the standard reaction conditions, the re- chemo-, regio- and E/Z-selectivities (entries 10–13).
action with 2a afforded the allyl–aryl coupling prod- These results demonstrated that this aqueous PdNPs-
uct 3u in almost quantitative yield (entry 7). The reac- catalyzed process is an extraordinarily active catalytic
tion still proceeded well when the catalyst loading system for the allyl–aryl coupling reaction. Notably,
was reduced to 0.1 mol% (entry 8). When further re- these are the first efficient examples for the reaction
ducing the catalyst loading to 0.02 mol% (S/C=5000), of the easily eliminated substrates as allylic partners.
the reaction gave coupling product 3u in 79% yield
The efficiency for the allyl–aryl coupling reaction
with complete selectivities within 72 h (entry 9). The of the easily eliminated substrates prompted asym-
reactions of allylic carbonate 1m were efficiently per- metric synthesis of 1,5-diene using this method of the
formed with arylboronic acids exhibiting different stereospecific allyl–aryl coupling of enantiomerically
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4 or 12 h. Then the mixture was extracted with CH2Cl2
(2.0 mLꢂ4). The organic layer was dried over Na2SO4, fil-
tered, and the filtrate was evaporated under reduced pres-
sure. The residue was purified by flash column chromatogra-
phy (SiO2: ethyl acetate: petroleum ether, 1:100–500) to fur-
nish corresponding allyl-aryl coupling products.
Acknowledgements
Scheme 5. Asymmetric synthesis of 1,5-diene (S)-3u.
This work was supported by Shanghai Pujiang Program
(11PJD012), National Key Basic Research Program of China
(2013CB934102), and Shanghai Jiao Tong University. We
thank Professor Chunai Che, Mr. Zhehao Huang and Chao
Wu for TEM analysis, and the Instrumental Analysis Center
of Shanghai Jiao Tong University for HR-MS analysis.
enriched 1m. 1,5-Dienes are abundant in naturally oc-
curring terpenes,[33] and these compounds have been
proved to be highly versatile intermediates and syn-
thetic building blocks.[34] Although there are some ap-
proaches for the preparation of 1,5-dienes,[35] the
asymmetric synthesis of chiral 1,5-dienes has been
achieved in recent years by the asymmetric allyl–allyl
coupling reaction.[36] As illustrated in Scheme 5, the
chiral 1-allyl-3-phenylallylic alcohol was readily syn-
thesized by Krischeꢀs Ir-catalyzed transfer hydrogena-
tive carbonyl allylation method,[37] and subsequently
underwent carbonation with ethyl chloroformate to
afford enantiomerically enriched allyl carbonate (R)-
1m with 87% ee. The reaction of (R)-1m with phenyl-
boronic acid (2a) in the presence of 0.1 mol% of
References
[1] a) A. Suzuki, Angew. Chem. 2011, 123, 6854; Angew.
Chem. Int. Ed. 2011, 50, 6722; b) G. A. Molander, B.
Canturk, Angew. Chem. 2009, 121, 9404; Angew. Chem.
Int. Ed. 2009, 48, 9240; c) N. Miyaura, Top. Curr. Chem.
2002, 219, 11; d) N. Miyaura, A. Suzuki, Chem. Rev.
1995, 95, 2457.
[2] J. Zhou, G. C. Fu, J. Am. Chem. Soc. 2004, 126, 1340.
[3] For a review of the cross-coupling of secondary alkyl
electrophiles, see: A. Rudolph, M. Lautens, Angew.
Chem. 2009, 121, 2694; Angew. Chem. Int. Ed. 2009, 48,
2656.
PdACHTUNGTRENNUNG(OAc)2 in water under ambient temperature for
24 h afforded chiral 1,5-diene (S)-3u in 91% yield
with complete stereospecificity.
[4] I. D. Hills, M. R. Netherton, G. C. Fu, Angew. Chem.
2003, 115, 5927; Angew. Chem. Int. Ed. 2003, 42, 5749.
[5] For examples of the Pd-catalyzed Suzuki–Miyaura cou-
pling of activated secondary alkyl electrophiles, see:
a) A. Hu, J. R. Falck, J. Am. Chem. Soc. 2010, 132,
2524; b) N. Rodrꢃguez, C. R. de Arellano, G. Asensio,
M. Medio-Simꢄn, Chem. Eur. J. 2007, 13, 4223.
[6] a) S. Norsikian, C.-W. Chang, Curr. Org. Synth. 2009, 6,
264; b) B. M. Trost, D. L. Van Vranken, Chem. Rev.
1996, 96, 395.
[7] a) H. Tsukamoto, T. Uchiyama, T. Suzuki, Y. Kondo,
Org. Biomol. Chem. 2008, 6, 3005; b) D. Bouyssi, V.
Gerusz, G. Balme, Eur. J. Org. Chem. 2002, 2445; c) H.
Chen, M.-Z. Deng, J. Organomet. Chem. 2000, 603,
189; d) Y. Kobayashi, R. Mizojiri, E. Ikeda, J. Org.
Chem. 1996, 61, 5391; e) J. Tsuji, T. Yamakawa, M.
Kaito, T. Mandai, Tetrahedron Lett. 1978, 2075.
[8] Y. Uozumi, H. Danjo, T. Hayashi, J. Org. Chem. 1999,
64, 3384.
Conclusions
In conclusion, we have developed an efficient method
for the highly selective and stereospecific allyl–aryl
coupling of secondary allylic carbonates with arylbor-
onic acids catalyzed by in situ generated PdNPs with-
out any ligands and additional stabilizers in water at
ambient temperature. The in situ generated PdNPs
showed extraordinary catalytic activity even for the
coupling reaction of easily eliminated allylic carbo-
nates under aqueous ambient conditions. The mecha-
nism of the process was investigated by TEM and ki-
netic studies. We believe that this study provides
a new aspect of the practical process for asymmetric
synthesis. Further studies will focus on gaining
a better understanding of the reaction mechanism.
[9] a) Y. M. A. Yamada, S. M. Sarkar, Y. Uozumi, J. Am.
Chem. Soc. 2012, 134, 3190; b) S. M. Sarkar, Y.
Uozumi, Y. M. A. Yamada, Angew. Chem. 2011, 123,
9609; Angew. Chem. Int. Ed. 2011, 50, 9437.
[10] M.-B. Li, Y. Wang, S.-K. Tian, Angew. Chem. 2012, 124,
3022; Angew. Chem. Int. Ed. 2012, 51, 2968.
Experimental Section
[11] C. Li, J. Xing, J. Zhao, P. Huynh, W. Zhang, P. Jiang,
General Procedure for the Allyl–Aryl Coupling
Y. J. Zhang, Org. Lett. 2012, 14, 390.
To 10-mL Schlenck flask equipped with a stir bar, was
[12] For Pd(II)-catalyzed g-selective stereospecific cross-
coupling of chiral secondary allylic acetates with aryl-
boronic acids, see: a) Y. Makida, H. Ohmiya, M. Sawa-
added Pd
ACHTUNGTRENNUNG(OAc)2 (0.005 mmol), 1 (0.5 mmol), 2 (0.75 mmol),
H2O (0.5 mL or 1 mL). The mixture was stirred at 258C for
496
asc.wiley-vch.de
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Adv. Synth. Catal. 2013, 355, 491 – 498

Stereospecific Allyl–Aryl Coupling Catalyzed by in situ Generated Palladium Nanoparticles in Water
mura, Chem. Asian J. 2011, 6, 410; b) D. Li, T. Tanaka,
H. Ohmiya, M. Sawamura, Org. Lett. 2010, 12, 3344;
c) H. Ohmiya, Y. Makida, D. Li, M. Tanabe, M. Sawa-
mura, J. Am. Chem. Soc. 2010, 132, 879; d) H. Ohmiya,
Y. Makida, T. Tanaka, M. Sawamura, J. Am. Chem.
Soc. 2008, 130, 17276.
[21] I. Lyothier, C. Defieber, E. M. Carreira, Angew. Chem.
2006, 118, 6350; Angew. Chem. Int. Ed. 2006, 45, 6204.
[22] P. R. Carlier, W. S. Mungall, G. Sohrçder, K. B. Sharp-
less, J. Am. Chem. Soc. 1988, 110, 2978.
[23] a) K. Bogar, P. H. Vidal, A. R. A. Leon, J.-E. Backvall,
Org. Lett. 2007, 9, 3401; b) A. Ghamen, H. Y. Aboul-
Enein, Tetrahedron: Asymmetry 2004, 15, 3331; c) K.
Faber, Biotransformations in Organic Chemistry, 5th
edn., Springer, Berlin, 2004; d) K. Drauz, H. Wald-
mann, Enzyme Catalysis in Organic Synthesis, Wiley-
VCH, Weinheim, 1995; e) C.-H. Wong, G. M. White-
sides, Enzymes in Organic Chemistry, Pergamon,
Oxford, 1994.
[24] a) K. Sawai, R. Tatumi, T. Nakahodo, H. Fujihara,
Angew. Chem. 2008, 120, 7023; Angew. Chem. Int. Ed.
2008, 47, 6917; b) D. Han, X. Li, H. Zhang, Z. Liu, G.
Hu, C. Li, J. Mol. Catal. A 2008, 283, 15; c) I. Favier,
M. Gomez, G. Muller, M. R. Axet, S. Castillon, C.
Claver, S. Jansat, B. Chaudret, K. Philippot, Adv.
Synth. Catal. 2007, 349, 2459; d) S. Jansat, D. Picurelli,
K. Pelzer, K. Philippot, M. Gomez, G. Muller, P. Le-
cante, B. Chaudret, New J. Chem. 2006, 30, 115; e) G.
Szollosi, A. Mastalir, Z. Kiraly, I. Dekany, J. Mater.
Chem. 2005, 15, 2464; f) S. Jansat, M. Gomez, K. Phil-
ippot, G. Muller, E. Guiu, C. Claver, S. Castillon, B.
Chaudret, J. Am. Chem. Soc. 2004, 126, 1592; g) M.
Tamura, H. Fujihara, J. Am. Chem. Soc. 2003, 125,
15742.
[13] For selected recent reviews, see: a) ꢅ. Molnꢆr, Chem.
Rev. 2011, 111, 2251; b) V. Polshettiwar, A. Decottig-
nies, C. Len, A. Fihri, ChemSusChem 2010, 3, 502;
c) B. H. Lipshutz, A. R. Abela, Z. V. Boskovic, T. Nish-
ikata, C. Duplais, A. Krasovskiy, Top. Catal. 2010, 53,
985; d) B. H. Lipshutz, S. Ghorai, Aldrichimica Acta
2008, 41, 59; e) L. Yin, J. Liebscher, Chem. Rev. 2007,
107, 133.
[14] N. A. Bumagin, V. V. Bykov, I. P. Beletskaya, Bull.
Acad. Sci. USSR Div. Chem. Sci. (Engl. Transl.) 1989,
38, 2206.
[15] For selected recent examples, see: a) J. Qiu, L. Wang,
M. Liu, Q. Shen, J. Tang, Tetrahedron Lett. 2011, 52,
6489; b) C. Liu, Q. Ni, F. Bao, J. Qiu, Green Chem.
2011, 13, 1260; c) W.-J. Zhou, K.-H. Wang, J.-X. Wang,
Z.-R. Gao, Tetrahedron 2010, 66, 7633; d) B. Basu, K.
Biswas, S. Kundu, S. Ghosh, Green Chem. 2010, 12,
1734; e) A. Del Zotto, F. Amoroso, W. Baratta, P. Rigo,
Eur. J. Org. Chem. 2009, 110–116.
[16] a) J. G. de Vries, Dalton Trans. 2006, 421; b) M. T.
Reetz, J. G. de Vries, Chem. Commun. 2004, 1559;
c) A. Alimardanov, L. Schmieder-van de Vondervoort,
A. H. M. de Vries, J. G. de Vries, Adv. Synth. Catal.
2004, 346, 1812; d) J. G. de Vries, A. H. M. de Vries,
Eur. J. Org. Chem. 2003, 799; e) M. T. Reetz, E. West-
ermann, Angew. Chem. 2000, 112, 170; Angew. Chem.
Int. Ed. 2000, 39, 165.
[25] Mixing PdACTHNUTRGNEUNG(OAc)2 (5 mmol) and phenylboronic acid
(0.75 mmol) in an organic solvent (0.5 mL) such as
THF and MeOH still formed PdNPs with an average
particle size of 3.0 and 2.9 nm, respectively, (see the
Supporting Information).
ˇ
[26] M. Moreno-Manas, M. Pꢇrez, R. Pleixats, J. Org.
[17] For selected recent reviews on Pd nanocatalysis for the
cross-coupling reaction, see: a) M. Pꢇrez-Lorenzo, J.
Phys. Chem. Lett. 2012, 3, 167; b) A. Fihri, M. Bouh-
rara, B. Nekoueishahraki, J.-M. Basset, V. Polshettiwar,
Chem. Soc. Rev. 2011, 40, 5181; c) A. Balanta, C.
Godard, C. Claver, Chem. Soc. Rev. 2011, 40, 4973;
d) R. Narayanan, C. Tabor, M. A. El-Sayed, Top. Catal.
2008, 48, 60; e) J. Durand, E. Teuma, M. Gꢄmez, Eur.
J. Inorg. Chem. 2008, 3577; f) D. Astruc, Inorg. Chem.
2007, 46, 1884; g) N. T. S. Phan, M. Van Der Sluys,
C. W. Jones, Adv. Synth. Catal. 2006, 348, 609.
Chem. 1996, 61, 2346.
[27] a) R. Narayanan, M. A. El-Sayed, J. Phys. Chem. B
2004, 108, 8572; b) R. Narayanan, M. A. El-Sayed, J.
Am. Chem. Soc. 2003, 125, 8340.
[28] For the TEM images for monitoring of the coupling re-
action, see the Supporting Information.
[29] a) ref.[17]; b) P.-P. Fang, A. Jutand, Z.-Q. Tian, C. Ama-
tore, Angew. Chem. 2011, 123, 12392; Angew. Chem.
Int. Ed. 2011, 50, 12184; c) A. V. Gaikwad, A. Holui-
gue, M. B. Thathagar, J. E. ten Elshof, G. Rothenberg,
Chem. Eur. J. 2007, 13, 6908.
[18] For PdNPs-catalyzed Suzuki–Miyaura couplings under
ambient temperature, see: a) Z. Du, W. Zhou, F. Wang,
J.-X. Wang, Tetrahedron 2011, 67, 4914; b) W. Han, C.
Liu, Z. Jin, Adv. Synth. Catal. 2008, 350, 501; c) A. K.
Diallo, C. Ornelas, L. Salmon, J. R. Aranzaes, D.
Astruc. Angew. Chem. 2007, 119, 8798; Angew. Chem.
Int. Ed. 2007, 46, 8644; d) R. Tatumi, T. Akita, H. Fuji-
hara, Chem. Commun. 2006, 3349; e) F. Lu, J. Ruiz, D.
Astruc, Tetrahedron Lett. 2004, 45, 9443.
[19] a) I. Sato, N. Asakura, T. Iwashita, Tetrahedron: Asym-
metry 2007, 18, 2638; b) D. Tomita, R. Wada, M. Kanai,
M. Shibasaki, J. Am. Chem. Soc. 2005, 127, 4138;
c) J. L. von dem Bussche-Hꢈnnefeld, D. Seebach, Tetra-
hedron 1992, 48, 5719; d) W. Oppolzer, R. N. Radinov,
Tetrahedron Lett. 1988, 29, 5645.
[30] L. K. Thalꢇn, A. Sumic, K. Bogꢆr, J. Norinder, A. K. A.
Persson, J.-E. Bꢉckvall, J. Org. Chem. 2010, 75, 6842.
[31] The reaction time was not optimized.
[32] The reaction of 1k with 2a (entry 5 of Table 3) gave
a trace amount of the elimination product (4%) as de-
termined by 1H NMR of the crude mixture.
[33] a) K. C. Nicolaou, T. Montagnon, Molecules that
Changed the World, Wiley-VCH, Weinheim, 2008;
b) E. Breitmaier, Terpenes – Flavors, Fragrances, Phar-
maca, Pheromones, Wiley-VCH, Weinheim, 2006.
[34] For selected examples of organic synthesis by using 1,5-
dienes, see: a) J. A. Feducia, M. R. Gagnꢇ, J. Am.
Chem. Soc. 2008, 130, 592; b) Y.-J. Zhao, S.-S. Chng, T.-
P. Loh, J. Am. Chem. Soc. 2007, 129, 492; c) T. J. Dono-
hoe, S. Butterworth, Angew. Chem. 2003, 115, 978;
Angew. Chem. Int. Ed. 2003, 42, 948; d) H. Nakamura,
Y. Yamamoto, in: Handbook of Organopalladium
[20] N. Arai, K. Azuma, N. Nii, T. Ohkuma, Angew. Chem.
2008, 120, 7567; Angew. Chem. Int. Ed. 2008, 47, 7457.
Adv. Synth. Catal. 2013, 355, 491 – 498
ꢁ 2013 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
asc.wiley-vch.de
497

Jingming Zhao et al.
FULL PAPERS
Chemistry for Organic Synthesis, Vol. ,2 (Eds.: E.-i. Ne-
gishi, A. de Meijere), Wiley-Interscience, West Lafay-
ette, 2002, p 2919; e) R. C. D. Brown, J. F. Keily,
Angew. Chem. 2001, 113, 4628; Angew. Chem. Int. Ed.
2001, 40, 4496; f) L. E. Overman, F. M. Knoll, J. Am.
Chem. Soc. 1980, 102, 865.
[36] a) L. A. Brozek, M. J. Ardolino, J. P. Morken, J. Am.
Chem. Soc. 2011, 133, 16778; b) P. Zhang, H. Le, R. E.
Kyne, J. P. Morken, J. Am. Chem. Soc. 2011, 133, 9716;
c) P. Zhang, L. A. Brozek, J. P. Morken, J. Am. Chem.
Soc. 2010, 132, 10686.
[37] a) I. S. Kim, M.-Y. Ngai, M. J. Krische, J. Am. Chem.
Soc. 2008, 130, 6340; b) I. S. Kim. M.-Y. Ngai, M. J. Kri-
sche, J. Am. Chem. Soc. 2008, 130, 14891.
[35] a) A. Jimꢇnez-Aquino, E. F. Flegeau, U. Schneider, S.
Kobayashi, Chem. Commun. 2011, 47, 9456; b) E. F.
Flegeau, U. Schneider, S. Kobayashi, Chem. Eur. J.
2009, 15, 12247; and references cited therein.
498
asc.wiley-vch.de
ꢁ 2013 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Adv. Synth. Catal. 2013, 355, 491 – 498