Cross-coupling of vinylethylene carbonates with arylboronic acids catalyzed by in situ generated palladium nanoparticles in water

Article abstract of DOI:10.1016/j.tetlet.2016.06.022

A practical and greener method of the cross-coupling of vinylethylene carbonates (VECs) with arylboronic acids has been described. The coupling reaction was catalyzed by in situ generated palladium nanoparticles (PdNPs) without any ligands and additional stabilizers in water under ambient conditions to provide useful 4-hydroxylprenylarenes and their derivatives in good to high yields.

Full text of DOI:10.1016/j.tetlet.2016.06.022

Tetrahedron Letters 57 (2016) 3268–3271
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Tetrahedron Letters
journal homepage: www.elsevier.com/locate/tetlet
Cross-coupling of vinylethylene carbonates with arylboronic acids
catalyzed by in situ generated palladium nanoparticles in water
Yuxue Mao a,y, Xing Zhai a,b,y, Ajmal Khan a,y, Jiong Cheng a, Xue Wu b, Yong Jian Zhang a,
⇑
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, PR China
b Key Laboratory for Organism Resources of the Changbai Mountain and Functional Molecules, Ministry of Education, and Department of Chemistry, Yanbian University, Yanji,
Jilin 133002, PR China
a r t i c l e i n f o
a b s t r a c t
Article history:
Received 12 February 2016
Revised 3 June 2016
Accepted 6 June 2016
Available online 16 June 2016
A practical and greener method of the cross-coupling of vinylethylene carbonates (VECs) with arylboronic
acids has been described. The coupling reaction was catalyzed by in situ generated palladium nanopar-
ticles (PdNPs) without any ligands and additional stabilizers in water under ambient conditions to
provide useful 4-hydroxylprenylarenes and their derivatives in good to high yields.
Ó 2016 Elsevier Ltd. All rights reserved.
Keywords:
Cross-coupling
Allyl–aryl coupling
Palladium nanoparticles
4-Hydroxylprenylarenes
Catalysis in water
Introduction
excess base are required for the process. Therefore, the develop-
ment of practical and greener methods for the synthesis of 4-
The 4-hydroxylprenylarene motif appears in a wide range of
biologically active natural products,1 yet efficient methods for
the introduction of 4-hydroxylprenyl group into aromatic rings
are largely unexplored. The approaches to 4-hydroxylprenylarenes
include selective oxidation of prenylarenes (Scheme 1 Eq. 1a),2 but
the transformation is not effective. 4-Hydroxylprenyl group could
also be introduced by Wittig olefination3 (Eq. 1b) and Stille cou-
pling4 (Eq. 1c). However, multi-steps syntheses are required
whether for arylacetaldehyde or the organostannane reagent. More
practical methods have been accomplished through transition
metal-catalyzed cross coupling of isoprene oxide with arylmetallic
compounds, including arylmercurates,5 arylstannanes,6 aryl-Grig-
nard reagents,7 arylbismuth,8 and arylsiloxanes9 (Scheme 1, Eq.
2). However, those arylmetallic compounds are moisture sensitive
and need to be pre-prepared. In addition, toxic metallic byproducts
are generated for the transformations using some of the arylmetal-
lic compounds. Szabó and co-workers reported only one example
for Pd-catalyzed cross-coupling of vinyl epoxides with arylboronic
acids to form 4-hydroxybut-2-enylarenes in high efficiency.10 Nev-
ertheless, a pre-prepared palladium pincer complex as catalyst and
hydroxylprenylarenes and their derivatives is highly appealing.
Transition metal-catalyzed cross-coupling of allylic elec-
trophiles with arylboronic acids is one of most practical methods
for the formation of valuable allyl–aryl coupling compounds.11,12
Recently, we reported palladium-catalyzed cross-coupling of
allylic donors with arylboronic acids to afford allyl–aryl coupling
products in high efficiency.13 We also demonstrated that the
allyl–aryl coupling could be catalyzed by palladium nanoparticles
(PdNPs) generated in situ from Pd(OAc)2 without any ligands and
additional stabilizers in pure water at ambient conditions.13c On
the other hand, we have recently found that vinylethylene
carbonates (VECs) as readily accessible and stable allylic donors
could be successfully applied to the Pd-catalyzed asymmetric
decarboxylative cycloadditions with unsaturated electrophiles to
construct quaternary stereocenters in very high efficiencies.14,15
Based on our continuous effort to the development of practical
and greener allyl–aryl coupling process, we herein will represent
PdNPs-catalyzed16 allyl–aryl coupling of VECs with arylboronic
acids to form 4-hydroxylprenylarenes and their derivatives
(Scheme 1, Eq. 3).17 The cross-coupling process could be carried
out effectively catalyzed by PdNPs generated in situ from the reac-
tion of arylboronic acids with Pd(OAc)2 in pure water at ambient
conditions.
⇑
Corresponding author.
y
These authors contributed equally to this work.
http://dx.doi.org/10.1016/j.tetlet.2016.06.022
0040-4039/Ó 2016 Elsevier Ltd. All rights reserved.

Y. Mao et al. / Tetrahedron Letters 57 (2016) 3268–3271
General approaches to 4-hydroxylprenylarenes
3269
Wittig olefination
and reduction
oxidation
a
Ar
Ar
PPh3
Ar
CHO
OH
4-hydroxylprenylarenes
+
Br
b
COOEt
(1)
c
Stille coupling
TBSO
Ar
Br
+
SnBu3
Coupling of methylvinylepoxide with arylmetal reagents
cat.
Ar
O
(2)
(3)
+
OH
M
Ar
Coupling of VECs with arylboronic acids (this work)
O
Ar
PdNPs
water
O
OH
+
ArB(OH)2
O
R
R
Scheme 1. Synthetic approaches to 4-hydroxylprenylarenes.
O
Pd(OAc)2
(1 mol%)
Me
Me
Ar
O
O
+
ArB(OH)2
OH
HO
Ar
H2O, 25 oC, 12 h
2
4
3
Me
1a
2a
2e
2b
, Ar = Ph, ; Ar = 4-MeOC6H4;
2c
2d
, Ar = 2-MeOC6H4; , Ar = 2-MeC6H4;
2f
2g 2h
, Ar = 4-BrC6H4; , Ar = 4-MeOOC C6H4; , Ar = 4-CF3C6H4; , Ar = 2,4-diMeO C6H4;
2i, Ar = 2,6-diMeO C6H4; 2j, Ar = 2,6-diMeO-4-(2-phenylethyl)C 6H4;
2k
2l
2m
, Ar = 3,4-OCH2OC6H4; , Ar = 1-naphthyl;
, Ar = 2-naphthyl
Me
Me
OH
OMe
Me
OH
OH
MeO
3aa
85% yield, E/Z = 2.5:1
3ab
3ac
80% yield, E/Z = 2.0:1
90% yield, E/Z = 1.7:1
Me
Me
Me Me
OH
OH
OH
Br
MeOOC
3ad
3ae
3af
78% yield, E/Z = 1.6:1
86% yield, E/Z = 2.7:1
77% yield, E/Z = 1.7:1
Me
OMe
Me
OMe
Me
OH
OH
OH
F3C
MeO
R
OMe
3ai
3ag
3ah
R = H
82% yield, E/Z = 1.7:1
3aj
97% yield, E/Z = 2.8:1
77% yield, E/Z = 2.0:1
R = Ph(CH2)2
95% yield, E/Z = 1.7:1
Me
Me
Me
OH
OH
OH
O
O
3ak
82% yield, E/Z = 2.0:1
3al
3am
95% yield, E/Z = 2.0:1
96% yield, E/Z = 2.4:1
Figure 1. PdNPs-catalyzed cross-coupling of Me-VEC 1a with arylboronic acids 2. Reaction conditions: 1a (0.5 mmol), 2 (0.75 mmol), Pd(OAc)2 (0.005 mmol), H2O (1.0 mL),
25 °C, 12 h. The yields are of isolated materials. The ratios of 3/4 and E/Z were determined by 1H NMR of the crude reaction mixture. All the examples gave linear products 3
predominantly (3:4 > 20:1).

3270
Y. Mao et al. / Tetrahedron Letters 57 (2016) 3268–3271
O
O
O
O
O
O
Pd(OAc)2
(1 mol%)
R
Me
1k
R
Me
OH
1b 1j
-
+
PhB(OH)2
2a
Ph
O
O
H2O, 25 oC, 12 h
O
R1 R2
O
3
O
O
Ph
1l
1m
1b, R = H; 1c, R = Ph(CH2)2; 1d, R = Ph; 1e, R = 3-MeOC6H4; 1f, R = 4-MeOC6H4
t
1g
1h
1i
1j
, R = 4- BuC6H4; , R = 3,4-OCH2OC6H4; , R = 2,6-diFC6H4; , R = 1-naphthyl
Ph
Ph
OH
OH
OH
Ph
Ph
Ph
3bab
3ca
3da
70% yield, E/Z =1.5:1
94% yield, E/Z =1.2:1
96% yield, E/Z =2.6:1
OMe
tBu
OMe
OH
Ph
OH
Ph
OH
Ph
3ea
3fa
3ga
90% yield, E/Z =1.7:1
91% yield, E/Z =2.2:1
97%yield, E/Z =3.0:1
O
O
F
F
OH
Ph
OH
OH
Ph
Ph
3ha
3ia
3ja
92% yield, E/Z =2.5:1
97% yield, E/Z =1.2:1
79% yield, E/Z =2.5:1
OH
Me
Ph
Ph
OH
OH
Ph
Ph
Me
3ka
3la
3ma
91% yield, E/Z =6:1
50% yield, only E
95% yield, only E
Figure 2. PdNPs-catalyzed cross-coupling of VECs 1 with phenylboronic acid (2a). As described for Fig. 1. bThe ratio of linear and branched products is 5:1.
product 3j would be a useful precursor for the synthesis of
natural product, radulanin A.18
Results and discussion
After the successful realization of the formation of 4-hydrox-
ylprenylarenes via cross-coupling of Me-VEC 1a, we subse-
quently turned our attention toward the elaboration of the
cross-coupling of substituted VECs with phenylboronic acid
(2a). As shown Fig. 2, the reaction of H-VEC 1b gave the cou-
pling product 3ba in 70% yield. In this case, the branched pro-
duct was found in an 1:5 ratio to 3ba. The 4-alkyl-substituted
VEC 1c was also tolerated in the reaction conditions to furnished
coupling product 3ca in 94% yield, but the poor E/Z-selectivity
was observed. The cross-coupling reaction of Ph-VEC 1d with
2a proceeded smoothly to afford 3da in 96% yield with a 2.6:1
of E/Z ratio. For the reactions of 4-aryl-substituted VECs 1e-i
bearing different steric and electronic nature, all performed well
giving corresponding coupling products 3ea-ia in high yields
with moderate E/Z selectivities. The reaction efficiency for the
4-(1-naphthyl)-VEC 1j was slightly decreased. 4,5-Dimethyl-VEC
1k could also be converted into the coupling product 3ka in
91% yield with high E/Z-selectivity. However, the reaction of
5,5-dimethyl-4-Ph-VEC 1l gave coupling product 3la in moderate
yield, but only E-isomer was obtained. Significantly, the cross-
coupling of VEC 1m with 2a afforded coupling adduct 3ma in
95% yield with only E-isomer.
Initially, in order to construct of 4-Hydroxylprenylarenes, 4-Me-
VEC 1a was chosen as a standard substrate. To our delight, the cou-
pling reaction of Me-VEC 1a with phenylboronic acid (2a) in the
presence of Pd(OAc)2 (1 mol%) at ambient temperature in pure
water proceeded smoothly to afford coupling product 3aa in 85%
yield with a 2.5:1 of E/Z ratio (Fig. 1), and the branched product
4 was not observed as determined by 1H NMR of the crude reaction
mixture. The reaction mixture turned black after a few minutes.
We find that the reaction in the initial stage produces PdNPs with
an average particle size of 4.6 nm by transmission electron micro-
scopy (TEM) analysis (see Supporting information). The particle
size has no big change after completion of the reaction. These
results indicated that Pd(OAc)2 was reduced to form PdNPs by
homo-coupling of phenylboronic acid, and the PdNPs are likely sta-
bilized by phenylboronic acid.13c These simple and practical
conditions were suitable for various arylboronic acids bearing
different steric and electronic properties at the phenyl ring,
providing 4-Hydroxylprenylarenes 3aa–ak in good to high yields
with 1.6–2.8:1 of E/Z ratios. The reactions with naphthylboronic
acids were also performed well to give coupling product 3l and
3m in excellent yields. All the examples gave linear products 3
predominantly (3:4 > 20:1). Notably, the allyl–aryl coupling

Y. Mao et al. / Tetrahedron Letters 57 (2016) 3268–3271
3271
O
O
O
O
B(OH)2
Pd(OAc)2
(1 mol %)
H2O, 25 oC, 24 h
O
O
O
+
MeO
OH
MeO
1h
5.0 mmol
2n
7.5 mmol
3hn
1.35 g, 91% yield
E/Z, 1.4:1
ref. 19
O
O
MeO
OH
Tenuifolin
Scheme 2. Gram-scale transformation.
3. (a) Meities, S.; Marquez, R. J. Org. Chem. 2008, 73, 5015; (b) Ref. 2a.
The synthetic utility of the present protocol was demonstrated
by the gram-scale transformation. The reaction of VEC 1h with
3-methoxylphenylboronic acid (3n) in 5.0 mmol scale proceeded
smoothly to furnish coupling adduct 3hn in 91% yield (1.35 g)
(Scheme 2). The coupling product 3hn would be a useful precursor
for the synthesis of natural product, tenuifolin.19
4. (a) Brandt, D. R.; Pannone, K. M.; Romano, J. J.; Casillas, E. G. Tetrahedron 2013,
69, 9994; (b) Yamaguchi, S.; Furihata, K.; Miyazawa, M.; Yokoyama, H.; Hirai, Y.
Tetrahedron Lett. 2000, 41, 4787.
5. Larock, R. C.; Ilkka, S. J. Tetrahedron Lett. 1986, 27, 2211.
6. (a) Tueting, D. R.; Echavarren, A. M.; Stille, J. K. Tetrahedron 1989, 45, 979; (b)
Echavarren, A. M.; Tueting, D. R.; Stille, J. K. J. Am. Chem. Soc. 1988, 110, 4039.
7. (a) Taber, D. F.; Mitten, J. V. J. Org. Chem. 2002, 67, 3847; (b) Jung, M. E.;
D’Amico, D. C. J. Am. Chem. Soc. 1995, 117, 7379.
8. Kang, S.-K.; Ryu, H.-C.; Hong, Y.-T.; Kim, M.-S.; Lee, S.-W.; Jung, J.-H. Synth.
Commun. 2001, 31, 2365.
Conclusion
9. (a) Jeganmohan, M.; Bhuvaneswari, S.; Cheng, C.-H. Angew. Chem., Int. Ed. 2009,
48, 391; (b) Herron, J. R.; Russo, V.; Valente, E. J.; Ball, Z. T. Chem. Eur. J. 2009, 15,
8713; (c) Matsuhashi, H.; Asai, S.; Hirabayashi, K.; Hatanaka, Y.; Mori, A.;
Hiyama, T. Bull. Chem. Soc. Jp. 1997, 70, 1943.
10. Kjellgren, J.; Aydin, J.; Wallner, O. A.; Saltanova, I. V.; Szabó, K. J. Chem. Eur. J.
2005, 11, 5260.
In conclusion, we have developed an efficient method for the
cross-coupling of VECs with arylboronic acids catalyzed by in situ
generated PdNPs without any ligands and additional stabilizers in
water at ambient temperature. The useful 4-hydroxylprenylarenes
and their derivatives have been provided under the mild and prac-
tical conditions. Further studies will focus on gaining a better
understanding of the reaction mechanism and finding reaction
conditions for control of the E/Z-selectivity.
11. For a review, see: Pigge, F. C. Synthesis 2010, 1745.
12. For selected recent examples, see: (a) Srinivas, H. D.; Zhou, Q.; Watson, M. P.
Org. Lett. 2014, 16, 3596; (b) Wu, H.-B.; Ma, X.-T.; Tian, S.-K. Chem. Commun.
2014, 50, 219; (c) Li, M.-B.; Wang, Y.; Tian, S.-K. Angew. Chem., Int. Ed. 2012, 51,
2968; (d) Yamada, Y. M. A.; Sarkar, S. M.; Uozumi, Y. J. Am. Chem. Soc. 2012, 134,
3190; (e) Sarkar, S. M.; Uozumi, Y.; Yamada, Y. M. A. Angew. Chem., Int. Ed. 2011,
50, 9437; (f) Ohmiya, H.; Makida, Y.; Li, D.; Tanabe, M.; Sawamura, M. J. Am.
Chem. Soc. 2010, 132, 879; (g) Nishikata, T.; Lipshutz, B. H. J. Am. Chem. Soc.
2009, 131, 12103; (h) Ohmiya, H.; Makida, Y.; Tanaka, T.; Sawamura, M. J. Am.
Chem. Soc. 2008, 130, 17276; (i) Yamada, Y. M. A.; Watanabe, T.; Torii, K.;
Uozumi, Y. Chem. Commun. 2009, 5594; (j) Tsukamoto, H.; Uchiyama, T.;
Suzuki, T.; Kondo, Y. Org. Biomol. Chem. 2008, 6, 3005.
13. (a) Xu, J.; Zhai, X.; Wu, X.; Zhang, Y. J. Tetrahedron 2015, 71, 1712; (b) Ye, J.;
Zhao, J.; Xu, J.; Mao, Y.; Zhang, Y. J. Chem. Commun. 2013, 49, 9761; (c) Zhao, J.;
Ye, J.; Zhang, Y. J. Adv. Synth. Catal. 2013, 355, 491; (d) Li, C.; Xing, J.; Zhao, J.;
Huynh, P.; Zhang, W.; Jiang, P.; Zhang, Y. J. Org. Lett. 2012, 14, 390.
14. (a) Khan, A.; Zhang, Y. J. Synlett 2015, 853; (b) Yang, L.; Khan, A.; Zheng, R.; Jin,
L. Y.; Zhang, Y. J. Org. Lett. 2015, 17, 6230; (c) Khan, A.; Xing, J.; Zhao, J.; Kan, Y.;
Zhang, W.; Zhang, Y. J. Chem. Eur. J. 2015, 21, 120; (d) Khan, A.; Zheng, R.; Kan,
Y.; Ye, J.; Xing, J.; Zhang, Y. J. Angew. Chem., Int. Ed. 2014, 53, 6439; (e) Khan, A.;
Yang, L.; Xu, J.; Jin, L. Y.; Zhang, Y. J. Angew. Chem., Int. Ed. 2014, 53, 11257.
15. Kleij, A. W.; Whiteoak, C. J. ChemCatChem 2015, 7, 51.
Acknowledgments
We gratefully acknowledge the Natural Science Foundation of
China (21572130), the National Key Basic Research Program of
China (2013CB934102), and the Innovation Program of Shanghai
Municipal Education Commission (14ZZ023) for financial supports.
We thank the Instrumental Analysis Center of Shanghai Jiao Tong
University for HRMS analysis.
Supplementary data
Supplementary data associated with this article can be found, in
the online version, at http://dx.doi.org/10.1016/j.tetlet.2016.06.
022.
16. For selected recent reviews for Pd nanocatalysis for the cross-coupling
reaction, see: (a) Pérez-Lorenzo, M. J. Phys. Chem. Lett. 2012, 3, 167; (b) Fihri,
A.; Bouhrara, M.; Nekoueishahraki, B.; Basset, J.-M.; Polshettiwar, V. Chem. Soc.
Rev. 2011, 40, 5181; (c) Balanta, A.; Godard, C.; Claver, C. Chem. Soc. Rev. 2011,
40, 4973; (d) Narayanan, R.; Tabor, C.; El-Sayed, M. A. Top. Catal. 2008, 48, 60;
(e) Durand, J.; Teuma, E.; Gómez, M. Eur. J. Inorg. Chem. 2008, 3577; (f) Astruc,
D. Inorg. Chem. 2007, 46, 1884; (g) Phan, N. T. S.; Van Der Sluys, M.; Jones, C. W.
Adv. Synth. Catal. 2006, 348, 609.
References and notes
1. For selected examples, see: (a) Ito, C.; Itoigawa, M.; Takakura, T.; Ruangrungsi,
N.; Enjo, F.; Tokuda, H.; Nishno, H.; Furukawa, H. J. Nat. Prod. 2003, 66, 200; (b)
Wu, T.-S.; Hsu, M.-Y.; Kuo, P.-C.; Sreenivasulu, B.; Damu, A. G.; Su, C.-R.; Li, C.-
Y.; Chang, H.-C. J. Nat. Prod. 2003, 66, 1207; (c) Góngora, L.; Giner, R.-M.; Máñez,
S.; Recio, M. C.; Ríos, J.-L. J. Nat. Prod. 2001, 64, 1111; (d) Ito, C.; Otsuka, T.;
17. Wang and Li reported independently Rh-catalyzed
a-C-H allylation with
vinylepoxide or H-VEC to form 4-hydroxylbut-2-enylarenes, see: (a) Zhang, S.-
S.; Wum, J.-Q.; Lao, Y.-X.; Lium, X.-G.; Liu, Y.; Lv, W.-X.; Tan, D.-H.; Zeng, Y.-F.;
Wang, H. Org. Lett. 2014, 16, 6412; (b) Yu, S.; Li, X. Org. Lett. 2014, 16, 1200.
18. (a) Stefinovic, M.; Snieckus, V. J. Org. Chem. 1998, 63, 2808; (b) Ref. 4b.
19. E/Z-isomerization was observed during the oxidative biaryl coupling step for
the synthesis of tenuifolin, see: Tang, C.; Li, Z.; Wang, Y.; Xu, J.; Kong, L.; Yao,
H.; Wu, X. Tetrahedron Lett. 2011, 52, 3275.
}
Ruangrungsi, N.; Furukawa, H. Chem. Pharm. Bull. 2000, 48, 334; (e) Tokés, A. L.;
Litkei, G.; Gulácsi, K.; Antus, S.; Baitz-Gács, E.; Szántay, C.; Darkó, L. L.
Tetrahedron 1999, 55, 9283; (f) Chung, M.-I.; Lai, M.-H.; Yen, M.-H.; Wu, R.-R.;
Lin, C.-N. Phychem. 1997, 44, 943.
2. (a) Gulácsi, K.; Litkei, G.; Autus, S.; Szántay, C.; Darkó, L. L.; Szelényi, J.; Haskó,
G.; Vizi, S. E. Arch. Pharm. Pharm. Med. Chem. 2001, 334, 53; (b) Matsuyama, S.;
Kuwahara, Y.; Suzuki, T. Agric. Biol. Chem. 1991, 55, 1409.