Zinc acetate as a catalyst for the hydroacylation reaction of azodicarboxylates with aldehydes

Article abstract of DOI:10.2174/157017812800233741

Abstract: Zn(OAc)2.2H2O is found to be an effective catalyst for the hydroacylation reaction of azodicarboxylates with aldehydes. A wide range of aldehydes, including aliphatic, aromatic and heterocyclic compounds, was considered. Most of the hydroacylati

Full text of DOI:10.2174/157017812800233741

Letters in Organic Chemistry, 2012, 9, 267-272
267
Zinc Acetate as a Catalyst for the Hydroacylation Reaction of
Azodicarboxylates with Aldehydes
Yuancheng Qin*, Dan Zhou and Mingjun Li
School of Environmental and Chemical Engineering, Nanchang Hangkong University, Nanchang, 330063, P. R. China
Received August 22, 2011: Revised December 15, 2011: Accepted January 18, 2012
Abstract: Zn(OAc)2·2H2O is found to be an effective catalyst for the hydroacylation reaction of azodicarboxylates with
aldehydes. A wide range of aldehydes, including aliphatic, aromatic and heterocyclic compounds, was considered. Most
of the hydroacylation reactions afforded the hydroacylation products in good to excellent yields. The overall system is
simple, economical and has practical advantages for construction of carbon-nitrogen bonds.
Keywords: Aldehydes, azo compounds, C-N bond formation, hydroacylation, zinc catalyst.
INTRODUCTION
has been no general study on the hydroacylation reaction
between aldehydes and azodicarboxylates catalyzed by zinc
catalysts. We wish to report here that zinc-catalyzed
hydroacylation between azodicarboxylates and aldehydes
provides the hydrazine under mild and ligand-free
conditions.
Carbon-nitrogen bond-forming reactions have great
importance in organic chemistry, since an overwhelming
number of biologically active compounds, natural as well as
nonnatural, are amino compounds or derivatives thereof [1].
Dialkyl azodicarboxylates, with a central azo functionality
flanked by two carboalkoxy groups, are excellent
electrophiles. They are commercially available. So, over the
last few decades, a very efficient reaction, which involves
the use of azodicarboxylates as electrophiles, has been
successfully used for such carbon-nitrogen bond formation
[2]. Hydroacylation reaction with direct functionalization of
the aldehydic C-H to form a variety of hydrazine imides is a
highly efficient synthetic methodology to form a carbon-
nitrogen bond. The hydroacylation reaction with aldehydes
has been studied under several conditions [3, 4]. However,
the reaction results in relatively low yields and requires long
times when aromatic aldehydes are used as the substrates. In
addition, very costly precious metals are used. Therefore,
there is the quest for newer and more efficient methods to
develop simple and efficient reaction conditions, while
increaseing the scope of the substrates without the use of
expensive metal catalyst.
RESULTS AND DISCUSSION
Initially, the hydroacylation reaction between diisopropyl
azodicarboxylate with benzaldehyde was selected as a model
reaction for optimizing the reaction conditions. Firstly, we
studied the effect of various solvents for the hydroacylation
reaction (Table 1). The reaction proceeded smoothly in
conventional organic solvents. The isolated yields were
significantly influenced by the solvent employed. Among the
solvents tested, MeCN was proven to be the best compared
to the others (Table 1, entry 1). EtOAc, Methanol, CH2Cl2,
DMF and 1,4-Dioxane could also provide relatively good
yields of the desired products (Table 1, entries 2, 5, 6 and 7).
Other solvents, EtOH and THF gave lower yields (Table 1,
entries 3 and 8).
The effect of catalyst loading on the hydroacylation
reaction is shown in Table 1. Poor yields were also obtained
without the use of a catalyst (Table 1, entries 9). The amount
of the zinc acetate dihydrate catalyst employed in the
reaction is important. When the catalyst loading was less
than 15 mol%, the yield of the corresponding product was
relatively lower (Table 1, entries 10 and 11). A yield of 80%
was obtained when 20 mol% Zn was applied (Table 1, entry
1), and the yield did not apparently improve further when the
Zn loading was more than 25 mol%. Only different reaction
rates were observed for the reaction (Table 1, entry 12). The
effect of the ratio of benzaldehyde to diisopropyl
azodicarboxylate was investigated. Lower ratio of
benzaldehyde to diisopropyl azodicarboxylate led to a
reduction of reaction yield (Table 1, entry 13 and 14).
Zinc stands out as a convenient alternative to costly
precious metals, because zinc salts are often cheap and
environmentally benign. Zinc-based catalyts can be applied
in many reactions. Mimoun et al. reported an excellent
achievement of economical reduction method with zinc
catalysts [5]. The zinc-catalyzed reduction of ketones was
followed by Carpentier [6], de Parrodi [7], Mikami [8], and
Riant [9]. Recently, zinc acetate proved to be an efficient
catalyst for hydrosilylation of ketones and aldehydes in the
combination with (EtO)2MeSiH [10]. Chakraborty et al. have
demonstrated that Zn(OAc)2·2H2O is a potent catalyst
towards the ring-opening polymerization of cyclic esters and
lactide [11].
Under our optimized reaction conditions, the scope of
this hydroacylation reaction was explored. A variety of
aldehydes were examined for the hydroacylation reactions.
As shown in Table 2, most of the hydroacylation reactions
afforded the hydroacylation products in good to excellent
yields. Aromatic aldehydes were good substrates for this
reaction and afforded the hydroacylation products in good
Zinc catalysts have proved to be active and versatile in
many types of reactions. To the best of our knowledge, there
*Address correspondence to this author at the School of Environmental and
Chemical Engineering, Nanchang Hangkong University, Nanchang, 330063,
P. R. China; Tel/Fax: +86-0791-83953373;
E-mail: qinyuancheng@yahoo.com.cn
1875-6255/12 $58.00+.00
© 2012 Bentham Science Publishers

268 Letters in Organic Chemistry, 2012, Vol. 9, No. 4
Qinet al.
Table 1. Optimization Reaction of Benzaldehyde with Diisopropyl Azodicarboxylatea
O
O
Zn(OAc)2
2H2O
O
N
O
CHO
N
O
+
O
N
solvent, r.t., 48 h
O
N
H
O
O
Entry
Solvent
Zn (mol%)
Yield (%)b
1
2
MeCN
EtOAc
MeOH
EtOH
20
20
20
20
20
20
20
20
0
80
54
51
38
52
56
61
42
<5
47
50
80
30c
54d
80e
3
4
5
CH2Cl2
DMF
6
7
1,4-Dioxane
THF
8
9
MeCN
MeCN
MeCN
MeCN
MeCN
MeCN
MeCN
10
11
12
13
14
15
10
15
25
20
20
20
aReaction conditions: diisopropyl azodicarboxylate (0.5 mmol), benzaldehyde (1 mmol), catalyst, solvent (3 mL), r.t., 48 h. bIsolated by silica gel column chromatography and based
on diisopropyl azodicarboxylate. cthe ratio of benzaldehyde to diisopropyl azodicarboxylate was 1.2:1. dthe ratio of benzaldehyde to diisopropyl azodicarboxylate was 1.5:1. ethe ratio
of benzaldehyde to diisopropyl azodicarboxylate was 2.5:1.
EXPERIMENTAL
yields. The hydroacylation reactions with benzaldehyde
obtained the desired products 1 in high yields (Table 2, entry
1). The electronic nature of the substituents, either electron-
withdrawing or electron-donating groups on the aromatic
aldehydes was affording hydroacylation products 2-5 in high
yields (Table 2, entries 2-5). To broaden the scope of the
reaction, heterocyclic compounds aldehydes were used in the
reaction and also gave the desired products in good yields
(50-64 %, Table 2, entries 6-8). The aldehydes with
unsaturation also provided the desired products in good
yields (Table 2, entry 9). The aliphatic saturated aldehydes,
with either linear or branched substituents when used in the
reaction with diisopropyl azodicarboxylate, afforded the
desired products in good to excellent yields (86-97%, Table
2, etries 10-13).
All chemicals were obtained from commercial sources
and used as received. H NMR and 13C NMR spectra were
1
recorded on a Bruker NMR spectrophotometer (400 MHz) in
CDCl3 solution at room temperature. Mass spectra were
obtained using Finnigan LCQ Advantage MAX
spectrometer.
General Procedure for the Hydroacylation Reaction of
Aldehydes and Azodicarboxylates Catalyzed by Zinc
acetate dihydrate
Aldehyde (1 mmol), azodicarboxylate (0.5 mmol) and
Zinc acetate dihydrate (0.1 mmol) were mixed in acetonitrile
(5 mL). The mixture was stirred at room temperature. When
the reaction was complete, the solution was evaporated and
the residue purified by column chromatography on silica gel
using hexane:ethyl acetate (5:1) as the eluent to afford the
product diisopropyl 1-acylhydrazine-1,2-dicarboxylate.
CONCLUSION
In conclusion, Zn(OAc)2·2H2O is found to be an effective
catalyst for the hydroacylation reaction of azodicarboxylates
with aldehydes. The corresponding target products were
obtained in good to excellent yields, and an array of
functional groups was tolerated under the mild conditions
with respect to aldehydes. The protocol used inexpensive
zinc acetate dihydrate as the catalyst, no additional ligand
and additive were required, so the overall system is simple,
economicals and has practical advantages for construction of
carbon-nitrogen bonds.
1
Hydroacylation Product 1: H NMR (400 MHz, CDCl3):
δ = 7.68-7.26 (m, 5H), 6.86 (s, 1H), 5.01-4.87 (m, 2H), 1.29
(d, J = 6 Hz, 6H), 0.99 (d, J = 6.8 Hz, 6H); 13C NMR (100
MHz, CDCl3): δ = 171.2, 155.3, 152.9, 135.2, 133.5, 131.8,
130.1, 128.4, 128.1, 72.4, 70.6, 22.9, 21.9, 21.6, 21.3; MS
(ESI) calcd for C15H20N2O5 M- 307.13, found: 307.17.
1
Hydroacylation Product 2: H NMR (400 MHz, CDCl3):
δ = 7.72 (s, 2H), 6.95-6.90 (m, 3H), 5.03-4.97 (m, 1H), 4.95-

Zinc Acetate as a Catalyst for the Hydroacylation Reaction
Letters in Organic Chemistry, 2012, Vol. 9, No. 4 269
Table 2. Hydroacylation Reaction of Aldehydes with Azobicarboxylatesa
O
R
O
O
Zn(OAc)2
2H2O
O
N
O
R
CHO
N
O
+
O
N
MeCN, r.t.,
O
N
H
O
Entry
Aldehyde
Time (h)
Product
Yield (%)b
O
O
1
CHO
48
80
O
N
N
H
O
O
1
H3CO
O
O
2
H3CO
CHO
32
83
O
N
N
O
H
O
2
O2N
O
O
O2N
CHO
3
96
62
O
N
N
O
H
O
3
Br
O
O
4
Br
CHO
52
67
O
N
N
O
H
O
4
N
O
O
5
N
CHO
96
54
O
N
N
O
H
O
5
S
O
O
6
70
64
O
N
CHO
S
N
H
O
O
6

270 Letters in Organic Chemistry, 2012, Vol. 9, No. 4
Qinet al.
(Table 2). Contd…..
Entry
Aldehyde
CHO
Time (h)
Product
Yield (%)b
63
7
18
S
O
O
S
O
N
N
H
O
O
7
8
46
n-C12H25
50
n-C12H25
CHO
S
S
O
O
O
N
N
O
H
O
8
9
CHO
48
70
O
O
O
N
NH
O
O
9
10
11
n-C11H23 CHO
18
22
n-C11H23
O
93
97
O
O
N
N
H
O
O
10
CHO
O
O
O
O
O
N
N
H
O
O
O
O
11
O
12
13
CHO
12
16
86
88
O
N
N
H
O
12
n-C6H13 CHO
n-C6H13
O
O
N
N
H
O
13
a
b
Reaction conditions: diisopropyl azodicarboxylate (0.5 mmol), aldehyde (1 mmol), Zinc acetate dihydrate (0.1 mmol), MeCN (5 mL), r.t. Isolated by silica gel column
chromatography and based on diisopropyl azodicarboxylate.
1
4.89 (m, 1H), 3.88 (s, 3H), 1.29 (d, J = 5.2 Hz, 6H), 1.13 (d,
J = 4.8 Hz, 6H); 13C NMR (100 MHz, CDCl3): δ = 170.6,
162.9, 155.4, 153.2, 132.2, 131.0, 126.9, 113.6, 113.4, 55.4,
21.9, 21.4; MS (ESI) calcd for C16H22N2O6 M- 337.14,
found: 337.04.
Hydroacylation Product 3: H NMR (400 MHz, CDCl3): δ =
8.29 (d, J = 8.4 Hz, 2H), 7.82 (d, J = 6.8 Hz, 2H), 5.05- 4.91
(m, 2H), 1.27, (d, J = 6 Hz, 6H), 1.15, (d, J = 5.2 Hz, 6H);
13C NMR (100 MHz, CDCl3): δ = 169.4, 155.2, 152.3, 149.2,
141.2, 130.5, 128.6, 124.3, 123.4, 73.2, 71.0, 21.9, 21.7,

Zinc Acetate as a Catalyst for the Hydroacylation Reaction
Letters in Organic Chemistry, 2012, Vol. 9, No. 4 271
21.4; MS (ESI) calcd for C15H19N3O7 M- 352.12, found:
352.16.
1.33-1.28 (m, 12H), 1.18-1.13 (m, 3H); 13C NMR (100 MHz,
CDCl3): δ = 174.7, 155.1, 152.6, 72.1, 70.3, 30.5, 21.8, 21.7,
8.9; MS (ESI) calcd for C11H20N2O5 M- 259.13, found:
259.15.
Hydroacylation Product 13: 1H NMR (400 MHz, CDCl3):
δ = 6.61 (s, 1H), 5.05-4.95 (m, 2H), 2.89 (s, 2H), 1.67-1.64
(m, 4H), 1.32-1.30 (m, 20H), 0.87 (b, J = 6.4 Hz, 5H); 13C
NMR (100 MHz, CDCl3): δ = 173.5 155.1, 152.5, 71.1, 69.9,
36.8, 31.7, 31.3, 28.6, 24.5, 22.5, 22.3, 22.1, 21.6, 21.2, 13.8;
MS (ESI) calcd for C15H28N2O5 M- 315.19, found: 315.17.
1
Hydroacylation Product 4: H NMR (400 MHz, CDCl3):
δ = 7.58 (d, J = 11.2 Hz, 4H), 7.04 (s, 1H), 5.03-4.97 (m,
1H), 4.94-4.88, (m, 1H), 1.27 (d, J = 13.2 Hz, 6H), 1.12 (d, J
= 5.2 Hz, 6H); 13C NMR (100 MHz, CDCl3): δ = 170.4,
155.2, 152.7, 133.9, 131.8, 131.6, 131.4, 129.7, 126.7, 72.7,
70.8, 21.9, 21.4; MS (ESI) calcd for C15H19BrN2O5 M-
385.04, found: 385.22.
1
Hydroacylation Product 5: H NMR (400 MHz, CDCl3):
δ = 7.76-7.70 (m, 2H), 6.90 (d, J = 7.2 Hz, 1H), 6.61 (t, J =
6.2 Hz, 1H), 6.38 (s, 1H), 5.05-4.92 (m, 2H), 3.09 (s, 6H),
1.26 (d, J = 6.4 Hz, 12H); 13C NMR (100 MHz, CDCl3): δ =
156.4, 153.7, 153.4, 112.1, 111.4, 110.9, 110.3, 72.2, 71.7,
40.0, 21.9, 21.7, 21.5; MS (ESI) calcd for C17H25N3O5 M-
350.17, found: 350.17.
CONFLICT OF INTEREST
Declared none.
ACKNOWLEDGEMENTS
The work was financially supported by Scientific
Research Foundation of Nanchang Hangkong University
(Grant EA201102178).
1
Hydroacylation Product 6: H NMR (400 MHz, CDCl3):
δ = 7.90 (t, J = 1.2 Hz, 1H), 7.61 (d, J = 4.8 Hz, 1H), 7.27 (d,
J = 2.4 Hz, 1H), 7.09 (d, J = 4.8 Hz, 1H), 6.95 (s, 1H), 5.08-
5.01 (m, 2H), 1.30 (d, J = 5.2 Hz, 12H); 13C NMR (100
MHz, CDCl3): δ = 162.7, 155.5, 152.7, 135.6, 134.7, 133.7,
127.2, 72.6, 70.8, 21.9, 21.6, 21.5; MS (ESI) calcd for
C13H18N2O5S M- 313.09, found: 313.13.
Hydroacylation Product 7: 1H NMR (400 MHz, CDCl3):
δ = 7.97 (s, 1H), 7.37 (s, 1H), 7.29-7.27 (m, 1H), 5.01-5.95
(m, 2H), 1.26 (d, J = 6.4 Hz, 6H), 1.19 (d, J = 5.6 Hz, 1H);
13C NMR (100 MHz, CDCl3): δ = 165.3, 155.3, 152.9, 136.0,
131.7, 127.6, 125.4, 72.4, 70.7, 21.9, 21.7, 21.4; MS (ESI)
calcd for C13H18N2O5S M- 313.09, found: 312.99.
REFERENCES
[1]
(a) Nair, V.; Menon, R. S.; Sreekanth, A. R.; Abhilash, N.; Biju, A.
T. Engaging Zwitterions in Carbon-Carbon and Carbon-Nitrogen
Bond-Forming Reactions: A Promising Synthetic Strategy. Acc.
Chem. Res. 2006, 39, 520; (b) Long, Y. H.; Zeng, H. P.; Yang, D.
Q. Highly Efficient Rhodium-Catalyzed Asymmetric Ring-
Opening Reactions of Oxabenzonorbornadiene with Amine
Nucleophiles. Catal. Lett. 2010, 138, 124. (c) Vargas, C.; Balu, A.
M.; Campelo, J. M.; Gonzalez-Arellano, C.; Luque, R.; Romero, A.
A. Towards Greener and More Efficient C-C and C-Heteroatom
Couplings: Present and Future. Curr. Org. Synth. 2010, 7, 568.
Nair, V.; Biju, A. T.; Mathew, S. C.; Babu, B. P. Carbon–Nitrogen
1
[2]
[3]
Hydroacylation Product 8: H NMR (400 MHz, CDCl3):
Bond-Forming Reactions of Dialkyl Azodicarboxylate:
A
δ = 7.71 (t, J = 6.4 Hz, 1H), 7.55-7.52 (m, 1H), 6.82 (s, 1H),
5.08-4.98 (m, 2H), 2.84 (t, J = 7.6 Hz, 2H), 1.71-1.65 (m,
2H), 1.32-1.13 (m, 26H), 0.99-0.86 (m, 7H), 13C NMR (100
MHz, CDCl3): δ = 173.5, 155.9, 135.2, 130.9, 128.8, 125.5,
72.3, 72.0, 31.9, 31.3, 30.5, 29.6, 29.5, 29.3, 29.2, 29.0, 27.7,
22.6, 21.9, 21.7, 19.1, 14.1; MS (ESI) calcd for C25H42N2O5S
M- 481.27, found: 481.37.
Promising Synthetic Strategy. Chem. Asian J. 2008, 3, 810.
(a) Schenck, G. O.; Formaneck, H. Zur Strahlenchemie des
Azodicarbonesters. Angew. Chem. 1958, 70, 505. (b) Huisgen, R.;
Jakob, F. Additionsreaktionen Der NN-Doppelbindung. 2. Der
Chemismus Einiger Weiterer Reaktionen Des Azodicarbonesters.
Justus Liebigs Ann. Chem. 1954, 590, 37. (c) González-Rosende,
M. E.; Lozano-Lucia, O.; Zaballos-Garcia, E.; Sepúlveda-Arques,
J. ChemInform Abstract: Reaction of N-Substituted 2-
Formylpyrroles with Azodicarbonylic Compounds. J. Chem. Res.,
Synop. 1995, 260. (d) Zaballos-García, E.; González-Rosende, M.
E.; Jorda-Gregori, J. M.; Sepúlveda-Arques, J.; Jennings, W. B.;
O’Leary, D.; Twomey, S. Ring transformation of furfural into an
unusual bicyclic system: Characterisation and dynamic
1
Hydroacylation Product 9: H NMR (400 MHz, CDCl3):
δ = 8.10 (d, J = 7.2 Hz, 1H), 7.81-7.29 (m, 7H), 5.09-4.99
(m, 2H), 1.31 (m, 12H); 13C NMR (100 MHz, CDCl3): δ =
170.5, 152.9, 145.8, 131.8, 130.9, 129.2, 128.9, 128.8, 128.6,
118.8, 72.3, 71.8, 21.8, 21.7, 21.2; MS (ESI) calcd for
C17H22N2O5 (M+Na)+ 357.14, found: 357.10.
Hydroacylation Product 10: 1H NMR (400 MHz, CDCl3):
δ = 6.67 (s, 1H), 5.05-4.94 (m, 2H), 2.89 (s, 2H), 1.65 (d, J =
6.8 Hz, 2H), 1.32-1.25 (m, 21H), 0.88 (t, J = 6.6 Hz, 3H); 13C
NMR (100 MHz, CDCl3): δ = 174.0, 155.1, 152.6, 72.1,
70.4, 31.9, 29.6, 29.4, 29.3, 29.2, 29.1, 29.0, 24.7, 24.6, 22.6,
21.8, 21.7, 14.1; MS (ESI) calcd for C20H38N2O5 (M+Na)+
409.27, found: 409.18.
Hydroacylation Product 11: 1H NMR (400 MHz, CDCl3):
δ = 6.79 (s, 1H), 5.07-4.94 (m, 2H), 3.66-3.60 (m, 1H), 1.32
(d, J = 6 Hz, 6H), 1.20 (d, J = 6.8 Hz, 12H); 13C NMR (100
MHz, CDCl3): δ = 178.3, 155.2, 152.5, 72.1, 70.3, 33.7,
21.8, 21.6, 19.3, 18.8; MS (ESI) calcd for C12H22N2O5 M-
273.15, found: 273.25.
stereochemistry
of
6,7-diethoxycarbonyl-6,7-diaza-8-
oxabicyclo[3,2,1]oct-3-en-2-one. Tetrahedron 1997, 53, 9313.
(a) Lee, D.; Otte, R. D. Transition-Metal-Catalyzed Aldehydic C-H
Activation by Azodicarboxylates. J. Org. Chem. 2004, 69, 3569.
(b) Kim, Y. J.; Lee, D. Use of N-N Bond Stereodynamics in Ring-
Closing Metathesis to Form Medium-Sized Rings and
Macrocycles. Org. Lett. 2004, 6, 4351. (c) Ni, B.; Zhang, Q.; Garre,
S.; Headley, A. D. Ionic Liquid (IL) as an Effective Medium for the
Highly Efficient Hydroacylation Reaction of Aldehydes with
Azodicarboxylates. Adv. Synth. Catal. 2009, 351, 875. (d) Zhang,
Q.; Parker, E.; Headley, A. D.; Ni, B. A Practical and Highly
Efficient Hydroacylation Reaction of Azodicarboxylates with
Aldehydes in Water. Synlett. 2010, 2453. (e) Qin, Y.; Peng, Q;
Song, J.; Zhou, D. Highly efficient copper-catalyzed
hydroacylation reaction of aldehydes with azodicarboxylates.
Tetrahedron Lett. 2011, 52, 5880. (f) Chudasama, V.; Ahern, J. M.;
Dhokia, D. V.; Fitzmaurice, R. J.; Caddick, S. Functionalisation of
aldehydes via aerobic hydroacylation of azodicarboxylates ‘on’
water. Chem. Commun. 2011, 47, 3269.
[4]
[5]
(a) Mimoun, H. Selective Reduction of Carbonyl Compounds by
Polymethylhydrosiloxane in the Presence of Metal Hydride
Catalysts. J. Org. Chem. 1999, 64, 2582. (b) Mimoun, H.; de Saint
Hydroacylation Product 12: 1H NMR (400 MHz, CDCl3):
δ = 6.73, (s, 1H), 5.07-4.93 (m, 2H), 2.92 (d, J = 6 Hz, 2H),

272 Letters in Organic Chemistry, 2012, Vol. 9, No. 4
Qinet al.
Laumer, J. Y.; Giannini, K.; Scopelliti, R.; Floriani, C.
[8]
[9]
Ushio, H.; Mikami, K. Asymmetric reduction of ortho-
multisubstituted benzophenones catalyzed by diamine–Zn–diol
complexes. Tetrahedron Lett. 2005, 46, 2903.
Gérard, S.; Pressel, Y.; Riant, O. Application of N,S-chelating
chiral ligands and zinc complexes in catalytic asymmetric
hydrosilylation using polymethylhydrosiloxane Tetrahedron:
Asymmetry 2005, 16, 1889.
Inagaki, T.; Yamada, Y.; Phong, L. T.; Furuta, A.; Ito, J.;
Nishiyama, H. Catalytic Hydrosilylation of Carbonyl Compounds
with Zinc(II) Acetate: Asymmetric Induction Collaborated with
N2S2 Ligands. Synlett., 2009, 253.
Gowda, R. R.; Chakraborty, D. Zinc acetate as a catalyst for the
bulk ring opening polymerization of cyclic esters and lactide.
Journal of Molecular Catalysis A: Chemical 2010, 333, 167.
Enantioselective
Reduction
of
Ketones
by
Polymethylhydrosiloxane in the Presence of Chiral Zinc Catalysts.
J. Am. Chem. Soc. 1999, 121, 6158
[6]
[7]
(a) Bette, V.; Mortrex, A.; Lehmann, C. W.; Carpentier, J.-F.
Direct Zn–diamine promoted reduction of C O and C N bonds
by polymethylhydrosiloxane in methanol. Chem. Commun. 2003,
332. (b) Bette, V.; Mortorex, A.; Savoia, D.; Carpentier, J.-F. New
developments in zinc-catalyzed asymmetric hydrosilylation of
ketones with PMHS. Tetrahedron 2004, 60, 2837.
Mastranzo, V. M.; Quintero, K.; de Parrodi, C. A.; Juaristi, E.;
Walsh, P. J. Use of diamines containing the α-phenylethyl group as
chiral ligands in the asymmetric hydrosilylation of prochiral
ketones. Tetrahedron 2004, 60, 1781.
[10]
[11]