Organocatalytic synthesis of cyanohydrin trimethylsilyl ethers by potassium 4-benzylpiperidinedithiocarbamate under solvent-free conditions

Article abstract of DOI:10.1002/aoc.1600

Potassium 4-benzylpiperidinedithiocarbamate was found to be an efficient organocatalyst for facile addition of trimethylsilyl cyanide to a wide variety of aldehydes and ketones to afford corresponding cyanohydrin trimethylsilyl ethers in high to quantitat

Full text of DOI:10.1002/aoc.1600

Full Paper
Received: 2 October 2009
Revised: 2 November 2009
Accepted: 2 November 2009
Published online in Wiley Interscience: 17 December 2009
(www.interscience.com) DOI 10.1002/aoc.1600
Organocatalytic synthesis of cyanohydrin
trimethylsilyl ethers by potassium
4-benzylpiperidinedithiocarbamate under
solvent-free conditions
Mohammad G. Dekamin∗†, Roghieh Alizadeh and M. Reza Naimi-Jamal
Potassium 4-benzylpiperidinedithiocarbamate was found to be an efficient organocatalyst for facile addition of trimethylsilyl
cyanide to a wide variety of aldehydes and ketones to afford corresponding cyanohydrin trimethylsilyl ethers in high to
quantitative yields. The reaction proceeded smoothly by employing 2.0 mol% PBPDC loading under mild conditions at room
c
temperature within a very short reaction time. Copyright ꢀ 2009 John Wiley & Sons, Ltd.
Keywords: cyanosilylation; organocatalysis; potassium 4-benzylpiperidinedithiocarbamate; carbonyl compounds; solvent-free condi-
tions
Introduction
organocatalysts are inert towards moisture and oxygen. Because
of these unique features, demanding reaction conditions like in-
ert atmosphere, low temperature, absolute solvents, etc., are in
many instances not required. Because of the absence of tran-
sition metals, organocatalytic methods seem to be especially
attractive for the preparation of compounds that do not toler-
ate metal contamination, e.g. pharmaceuticals. Therefore, they
have a high industrial and also ecological potential to be ap-
plied in many branches of chemical science and industry.[42–46]
Although some organocatalytic protocols have been described
for cyanosilylation of carbonyl compounds,[47–71] development
of new methods which are catalytic in nature, cost-effective and
simple to use is a very active research effort. The bidentate
dithiocarbamate ligand has proved to be an extremely versatile
and robust motif in coordination chemistry. Its ease of forma-
tion and wide ranging coordination chemistry have received a
great deal of attention from both academia and industry. Ex-
amples are metal-directed self-assembly,[72,73] speciation of trace
elements using non-chromatographic methods,[74–77] biological
studies[78,79] and catalysis by transition metals.[80–83] However,
there are very few reports available in the literature regarding the
use of pure dithiocarbamate (DTC) anions as nucleophilic catalysts
in organic transformations. We have previously reported sodium
or potassium piperidinedithiocarbamate as effective catalysts for
the efficient cyclotrimerization of aryl and alkyl isocyanates under
The addition of cyanide to carbonyl compounds is one of the
most powerful strategies for the synthesis of cyanohydrins as
poly-functionalized organic molecules. Cyanohydrins are highly
versatile synthetic blocks in organic synthesis as they may be easily
converted into other functional groups such as α-hydroxy acids,
α-hydroxy aldehydes or ketones, α-amino acids, β-amino alcohols,
1,2-diols, etc. Because of their importance in the pharmaceutical,
agrochemical and other industrial applications, a large body
of work has been devoted to the development of cyanohydrin
synthesis.[1–5] Various cyanide sources, such as HCN, NaCN, KCN
and different trialkylsilyl cyanides have been reported for the
nucleophilic addition of cyanide to carbonyl compounds. In
particular, the use of trimethylsilyl cyanide (TMSCN) in organic
synthesis has proven valuable from the standpoints of improving
of the reaction yield, safety and simplicity in the hydrolysis of the
products under mild conditions. However, this compound is only
effective in the transfer of the CN group to the carbonyl group of
aldehydes or ketones under the action of activators.[6–12]
Many different catalytic systems including Lewis acids[8–22]
and inorganic Lewis bases[23–26] have been developed for the
addition of TMSCN to carbonyl compounds. Furthermore, double
activating[3,27–35] orbifunctional[36–41] catalyticsystemshavebeen
described for asymmetric synthesis of cyanohydrin trimethylsilyl
ethers. However, many of these procedures suffer from many
disadvantages, such as the requirement for relatively expensive
heavy metal catalysts, anhydrous toxic solvents, inert atmosphere
and drastic reaction conditions with tedious work-up procedures.
On the other hand, organocatalytic protocols for organic synthe-
sis have received considerable attention in recent years because
they provide a platform for catalyzing reactions in the absence
of precious or toxic transition metals. Many organocatalysts are
simple molecules that show excellent selectivity and afford good
yield. Organocatalysts have several advantages. They are usu-
ally robust, inexpensive, readily available and non-toxic. Many
∗
Correspondenceto:Mohammad G. Dekamin,PharmaceuticalandBiologically-
Active Compounds Research Laboratory, Department of Chemistry, Iran
University of Science and Technology, Tehran 16846-13114, Iran.
E-mail: mdekamin@iust.ac.ir
†
Previous name: Mohammad G. Dakamin.
Pharmaceutical and Biologically-Active Compounds Research Laboratory,
Department of Chemistry, Iran University of Science and Technology, Tehran
16846-13114, Iran
c
Appl. Organometal. Chem. 2010, 24, 229–235
Copyright ꢀ 2009 John Wiley & Sons, Ltd.

M. G. Dekamin, R. Alizadeh and M. Reza Naimi-Jamal
General Procedure for Cyanosilylation of Carbonyl Com-
pounds
S
S
S
S
S
S
N
N
N
K
Na
Ph
Na
TMSCN (1.2 mmol, 0.15 ml) was added to a mixture of 1.0 mmol
of carbonyl compound and PBPDC (1, 0.02 mmol, 5.8 mg). The
resulting mixture was stirred at room temperature for time
indicated in Table 2. The reaction was monitored by TLC. After
completion,thereactionmixturewasquenchedwithwater(1.0 ml)
and the organic materials were extracted with EtOAc (2 × 1.5 ml).
The organic phase was washed with brine followed by water
(1.5 ml) and dried over MgSO4. The solvent was evaporated
under reduced pressure to afford the desired products which
in some cases were essentially pure cyanohydrin TMS ethers.
Further purification of the products could be performed by silica
gel column chromatography (EtOAc–hexane, 1 : 10). The isolated
yieldswereingoodagreementwiththoseobtainedbyGCanalysis.
1
2
3
Figure 1. Different dithiocarbamate anions used for catalyst survey.
solvent-free conditions.[84] Furthermore, considerable advance-
ment has been made during the past few years for the Lewis
base-catalyzed reactions, using silylated reagents.[23,50] In contin-
uation of our research for new efficient organocatalysts,[48–51,57]
we decided to investigate the possibility of using different nu-
cleophilic dithiocarbamate anions 1–3 (Fig. 1) to catalyze the
cyanosilylation of carbonyl compounds with TMSCN. Herein,
we wish to report potassium 4-benzylpiperidinedithiocarbamate
(PBPDC, 1) as an efficient catalyst for the rapid cyanosilylation of
carbonyl compounds with TMSCN under solvent-free conditions
(Scheme 1).
Results and Discussion
To examine the catalytic activity of the dithiocarbamate anions
1–3 for cyanosilylation of carbonyl compounds, the reaction
of 4-cholorobenzaldehyde 4a and TMSCN was carried out in
the presence of potassium 4-benzylpiperidinedithiocarbamate
(PBPDC, 1), sodium pyrrolidinedithiocarbamate (SPIDC, 2) and
sodium diethyldithiocarbamate (SDEDC, 3) (2 mol %), respectively
(Table 1, entries 1–3). As shown in Table 1, the catalytic ability of
dithiocarbamate anions is tightly associated with lipophilicity and
rigidity of the anion moiety as well as bulkiness of the counter
cation (entries 1–3). As can be seen, PBPDC 1 was found to be
the best catalyst for this reaction at room temperature. On further
increase of catalyst loading from 2 to 3 mol%, the reaction yield
and time did not alter remarkably (entry 4). On the other hand,
decreasing the catalyst loading to 1 mol% required longer time
for completion of the reaction (entry 5). In addition, no reaction
was observed in the absence of any dithiocarbamate anions 1–3
(entry 6). Accordingly, 2 mol% catalyst loading under solvent-free
conditions at room temperature was found to be the optimal
S
N
K
S
Ph
(2 mol%)
O
OSiMe3
1
CN
R'
R
R'
R
1.2 equiv. TMSCN
Solvent-Free, r.t.
R = Aryl, Alkenyl, Alkyl
R' = H, Alkyl
Scheme 1. Cyanosilylation of carbonyl compounds catalyzed by PBPDC.
Experimental
Materials and Instruments
Sodium diethyldithiocarbamate (SDEDC, 2) and sodium pyrro-
lidinedithiocarbamate (SPIDC, 3) were purchased from Merck. The
catalysts were powdered and dried at 70 ◦C for 1 h under reduced
pressure prior to use. Other chemicals were supplied by Merck,
Aldrich or Fluka and used as received except for benzaldehyde,
for which a fresh distilled sample was used. Analytical TLC was
carried out using Merck 0.2 mm silica gel 60 F-254 Al-plates. FT IR
spectra were recorded as KBr pellets on a Shimadzu FT IR-8400S
spectrometer. 1H NMR (500 MHz) and 13C NMR (125 MHz) spectra
were obtained using a Bruker DRX-500 Avance spectrometer. All
NMR spectra were determined in CDCl3 at ambient temperature.
GC chromatograms were recorded on Shimadzu 2010 and Perkin-
Elmer 8420 instruments. Melting points were determined using an
Electrothermal 9100 apparatus and are uncorrected.
Table 1. Optimization of cyanosilylation of 4-cholorobenzaldehyde
4a catalyzed by different dithiocarbamate anions under solvent-free
conditions and ambient temperaturea
O
OSiMe3
1-3
CN
H
H
Cl
1.2 equiv. TMSCN
Solvent-Free, r.t.
Cl
4a
5a
Time
Yieldb
(%)
TOFd
Entry
Catalyst
(Mol%)
(min)
TONc
(h−1
)
1
2
3
4
5
6
PBPDC, 1
SPIDC, 2
SDEDC, 3
PBPDC, 1
PBPDC, 1
–
2
2
2
3
1
–
10
25
40
6
98
88
84
95
93
0
49
44
42
32
93
0
294
106
63
PreparationofPotassium4-Benzylpiperidinedithiocarbamate
(PBPDC, 1)
To a 50 ml round-bottom flask equipped with a magnetic
stirrer and a condenser were added stoichiometric amounts
of 4-benzylpiperidine (10 mmol in 10 ml of diethyl ether), KOH
(10 mmol in 10 ml of distilled water) and CS2 (10 mmol). The
mixturewasstirredfor1 hatroomtemperature.Afterseparationof
phases, the resulting yellow precipitate was collected by filtration.
Thewaterphasewasalsoevaporatedandthesolidresiduewashed
with diethyl ether. The combined solids were powdered and dried
at 70 ◦C for 1 h under reduced pressure prior to use.[75–77]
317
124
0
45
180
a A 1.2 mmol aliquot of TMSCN was added to a mixture of 1.0 mmol of
4-cholorobenzaldehyde and 0.02 mmol of PBPDC.
b Determined by GC analysis.
c Turnover number: moles of product per mole of catalyst.
d Turnover frequency: moles of product per mole of catalyst per hour.
c
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Copyright ꢀ 2009 John Wiley & Sons, Ltd.
Appl. Organometal. Chem. 2010, 24, 229–235

Organocatalytic synthesis of cyanohydrin trimethylsilyl ethers
Table 2. Addition of TMSCN to aldehydes and ketones mediated by potassium 4-benzylpiperidinedithiocarbamate (PBPDC) at optimal conditionsa
Time
(min)
Conversion
(%)c
Entry
1
Carbonyl compound
Productb
OSIMe3
CN
10
98
O
H
H
Cl
4a
4b
Cl
5a
5b
2
3
15
100
O
O
OSIMe3
H
H
CN
H
Br
Br
5
99
OSIMe3
CN
H
O2N
O2N
4c
5c
4
5
6
5
10
7
99
98
99
NO2
O
NO2 OSIMe3
H
CN
H
4d
5d
O
OSIMe3
O2N
O2N
H
CN
H
4e
5e
O
OSIMe3
H
CN
H
NC
NC
5f
4f
7
8
15
15
100
96
OSIMe3
CN
O
H
H
4g
5g
OSIMe3
O
CN
H
H
Me
Me
5h
4h
4i
9
15
10
95
96
O
OSIMe3
CN
H
H
MeO
MeO
5i
10
OMe O
OMe OSIMe3
CN
H
H
5j
4j
11
12
15
20
100
92
O
OSiMe3
O
S
O
CN
H
H
4k
4l
5k
O
OSiMe3
S
CN
H
H
5l
c
Appl. Organometal. Chem. 2010, 24, 229–235
Copyright ꢀ 2009 John Wiley & Sons, Ltd.
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M. G. Dekamin, R. Alizadeh and M. Reza Naimi-Jamal
Table 2. (Continued)
Time
(min)
Conversion
Entry
13
Carbonyl compound
Productb
(%)c
25
98
OSiMe3
CN
O
H
H
5m
5n
4m
14
35
100
O
OSiMe3
CN
H
H
O
4n
15
16
17
60
180
120
98
94
97
OSiMe3
CN
H
H
4o
5o
O
OSiMe3
CN
4p
Me
5p
OSiMe3
O
NC
5q
4q
Me
O
18
19
180
150
62
O
OSIMe3
CN
Me
5r
4r
100
OSIMe3
CN
CH3
CH3
O2N
O2N
4s
5s
20
21
22
240
180
150
75
94
96
OSIMe3
CN
O
Ph
Ph
5t
4t
OSIMe3
O
CN
Ph
Ph
F
F
4u
5u
O
OSIMe3
CN
Ph
Ph
O2N
O2N
4v
5v
a A 1.2 mmol aliquot of TMSCN was added to a mixture of 1.0 mmol of carbonyl compound and 0.02 mmol of PBPDC under solvent-free conditions at
room temperature.
b All products are known and were well-characterized by IR and NMR spectral data as compared with those obtained from authentic samples or
reported in the literature.[9,12,17,18,20,21,35,50,54,70]
c Determined by GC analysis.
conditions in terms of obtained turnover number (TON) and
turnover frequency (TOF).
may be employed in the PBPDC-catalyzed process to afford the
corresponding cyanohydrin trimethylsilyl ethers in 92–100%
yields (entries 1–15). Upon completion of the reactions, the
catalyst was removed from the reaction mixture simply by
extraction to the aqueous phase used for quenching of any
intact TMSCN. Aldehydes bearing electron-withdrawing groups
such as NO2 –or CN–(entries 3–6), were more active than those
The optimized reaction conditions were applicable for a wide
range of representative carbonyl compounds with excellent to
quantitative yields and short reaction times. The results have
been summarized in Table 2. The data illustrated in Table 2
clearly demonstrates that a variety of aryl and alkyl aldehydes
c
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Copyright ꢀ 2009 John Wiley & Sons, Ltd.
Appl. Organometal. Chem. 2010, 24, 229–235

Organocatalytic synthesis of cyanohydrin trimethylsilyl ethers
Me
Me Si CN
Me
S
M
S
S
M
Me
Si
N
C
Me
Si
N
C
Me
CN
Me
CN
S
Me
Me
I
II
S
S
M
N
C
O
R
R'
1-3
Penta-Coordinated
Intermediates
Hexa-Coordinated
Intermediates
4
OSiMe3
S
CN
R'
R
Me
N
C
M
Me
Me
S
Si
O
M
Me
Si
N
S
C
Me
Me
5
R
R'
S
O
CN
R
R'
CN
IV
Scheme 2. Plausible mechanism for cyanosilylation of carbonyl compounds catalyzed by PBPDC.
III
Table 3. Comparison of some of the results obtained by cyanosilylation of aldehydes ketones with TMSCN in the presence of PBPDC (1), with some
of those reported by imidazolium-carbodithioate zwitterions (2), K2CO3 (3), triethanolamine N-oxide combined with dibenzyldimethylammonium
bromide (4), monobenzyloctahydropyrimido(1,2:a)azepinium bromide (5) and different lanthanide–nitrogen complexes (6) at room temperature
Method [equivalent of TMSCN : TOF (h−1)]
Entry
Substrate
1a
2[52]b
3[24]c
4[47]b
5[56]b
6[17]b
1
2
3
4
5
6
7
Benzaldehyde
4-Chlorobenzaldehyde
4-Methoxylbenzaldehyde
Cinnamaldehyde
1.2 : 200
1.2 : 294
1.2 : 190
1.2 : 118
1.2 : 86
2.0 : 0.62
1.2 : 55
1.2 : 110
1.2 : 5.2
1.2 : 9.1
–
–
1.2 : 4.2
–
2.2 : 0.62
–
–
2.2 : 0.61
2.0/0.15
–
–
1.2 : 4.3
1.2 : 12
1.2 : 16
–
–
–
–
–
–
–
3-Phenylpropanal
Acetophenone
–
–
2.2 : 0.26
–
1.2 : 10
1.2 : 0.13
1.2 : 0.55
2.0 : 2.5
2.0 : 2.5
Cyclohexanone
1.2 : 24
–
a The reactions were carried out under solvent-free conditions.
b The reactions were carried out in CH2Cl2 as solvent.
c The reactions were carried out in Et2O as solvent.
with electron-donating groups (entries 8–12). Interestingly, this
catalytic system well tolerated acid-labile substrates such as
the furfural, thiophen-2-carbaldehyde and cinnamaldehyde to
provide the corresponding products in excellent yields (entries
11–13). In addition, only 1,2-addition product was observed for
α,β-unsaturated aldehyde (entry 13).[10–12] The reaction with
aromatic and heterocyclic aldehydes afforded the corresponding
products in shorter reaction times compared with aliphatic
aldehydes (entries 13–15). It is of particular interest to note
that by-products such as those which could be produced by
desilylation or benzoin condensation were not observed in all of
the reactions studied.[58,59]
quired longer reaction times compared with aldehydes due to
increasing the steric hindrance around the carbonyl functional
group.[20,21]
The following Lewis basic mechanism may be proposed for
cyanosilylation of carbonyl compounds with TMSCN catalyzed
by different dithiocarbamate nucleophiles as organocatalysts
(Scheme 2). Therefore, the bidentate dithiocarbamate organocat-
alyst can interact with TMSCN to produce the pentacoordinate
intermediate I. It is noteworthy that the catalytic activity of differ-
ent nucleophilic catalytic systems, such as fluoride ion,[25,26] as well
as oxygen-containing[47–51] or sulfur-containing nucleophiles,[52]
can be correlated with the dissociation energies of the formed
bonds between Si and the nucleophilic centers to produce
pentacoordinate silicon complexes.[5,65] The catalytic activity of
dithiocarbamate anions may be intensified by the presence of
second nucleophilic centers to form hexacoordinated silicon com-
In the next step, the procedure was further explored by con-
version of aliphatic or aromatic ketones into their corresponding
cyanohydrin trimethylsilyl ethers (5p–v) in high yields within
short reaction time (entries 16–22). In general, ketones re-
c
Appl. Organometal. Chem. 2010, 24, 229–235
Copyright ꢀ 2009 John Wiley & Sons, Ltd.
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M. G. Dekamin, R. Alizadeh and M. Reza Naimi-Jamal
plexes analogous to that suggested by Olah and co-workers for
carbonateanion(intermediateII).[23] Interestingly,formationofthe
later silicon complex could be facilitated by the presence of the
nitrogen atom in the proximity of the second nucleophilic sulfur
atoms. This pattern of reactivity could be attributed to the vacant
3d-orbitalinsiliconatom.[57] Thecyanidenucleophilecanthenadd
to the carbonyl compound, and the resulting alkoxide anion can
coordinate to the silicon atom of the coordination sphere. Again
a penta- or hexacoordinated intermediate (III or IV) is possible.
Collapsing the later intermediates affords the desired cyanohydrin
trimethylsilyl ethers (5) with the regeneration of the catalysts.
To illustrate the efficiency of the new method, Table 3 compares
ourresultswithsomeofthosereportedintheliterature.[17,24,47,52,56]
[20] N. H. Khan, S. Agrawal, R. Kureshy, S. H. R. Abdi, S. Singh, R. V. Jasra,
J. Organomet. Chem. 2007, 692, 4361.
[21] B. Karimi, L. Ma’Mani, Org. Lett. 2004, 6, 4813.
[22] M. Bandini, P. G. Cozzi, P. Melchiorre, A. V. Ronchi, Tetrahedron Lett.
2001, 42, 3041.
[23] G. K. S. Prakash, H. Vaghoo, C. Panja, V. Surampudi, R. Kultyshev,
T. Mathew, G. A. Olah, Proc. Natl Acad. Sci. USA 2007, 104, 3026.
[24] B. He, Y. Li, X. Feng, G. Zhang, Synlett 2004, 1776.
[25] S. S. Kim, J. Rajagopal, D. H. Song, J. Organomet. Chem. 2004, 689,
1734.
[26] S. S. Kim, J. T. Lee, S. H. Lee, Bull. Korean Chem. Soc. 2005, 26, 993.
[27] D. H. Ryu, E. J. Corey, J. Am. Chem. Soc. 2005, 127, 5384.
[28] D. H. Ryu, E. J. Corey, J. Am. Chem. Soc. 2004, 126, 8106.
[29] H. Deng, M. P. Isler, M. L. Snapper, A. H. Hoveyda, Angew. Chem. Int.
Ed. 2002, 41, 1009.
[30] B. M. Trost, S. Martinez-Sanchez, Synlett. 2005, 627.
[31] Q. Li, X. Liu, J. Wang, K. Shen, X. Feng, Tetrahedron Lett. 2006, 47,
4011.
[32] Y. Xiong, X. Huang, S. H. Gou, Y. H. Weng, X. Feng, Adv. Synth. Catal.
2006, 348, 538.
Conclusion
[33] Z. Zeng, G. Zhao, P. Gao, H. Tang, B. Chen, Z. Zhou, C. Tang, Catal.
Commun. 2007, 8, 1443.
[34] G. J. Rowlands, Synlett 2003, 326.
[35] G. Rajagopal, S. S. Kim, S. C. George, Appl. Organomet. Chem. 2007,
21, 198.
[36] M. Kanai, N. Kato, E. Ichikawa, M. Shibasaki, Synlett 2005, 1491.
[37] S. Masumoto, M. Suzuki, M. Kanai, M. Shibasaki, Tetrahedron Lett.
2002, 43, 8647.
In conclusion, potassium 4-benzylpiperidinedithiocarbamate
(PBPDC) was found to be a mild and efficient nucleophilic
organocatalyst for promoting cyanosilylation of carbonyl com-
pounds under solvent-free conditions. The excellent functional
group tolerance, high to quantitative yields, availability of in-
expensive starting materials together with the simplicity of the
reaction and green methodology provide a convenient and practi-
calmethodforthepreparationofcyanohydrintrimethylsilylethers
after short reaction time.
[38] K. Yabu, S. Masumoto, M. Kanai, D. P. Curran, M. Shibasaki,
Tetrahedron Lett. 2002, 43, 2923.
[39] Y. Hamashima, M. Kanai, M. Shibasaki, J. Am. Chem. Soc. 2000, 122,
7412.
[40] C. Baleiza˜o, B. Gigante, H. García, A. Corma, Tetrahedron 2004, 60,
10461.
Acknowledgments
[41] K. Shen, X. Liu, Q. Li, X. Feng, Tetrahedron 2008, 64, 147.
[42] D. W. C. MacMillan, Nature 2008, 455, 304.
[43] P. I. Dalko, L. Moisan, Angew. Chem. Int. Ed. 2004, 43, 5138.
[44] M. T. Reetz, B. List, S. Jaroch, H. Weinmann (Eds.), Organocatalysis,
Springer: Berlin, 2008.
[45] J. Seayad, B. List, Org. Biomol. Chem. 2005, 3, 719.
[46] P. I. Dalko, L. Moisan, Angew. Chem. Int. Ed. 2001, 40, 3726.
[47] H. Zhou, F. X. Chen, B. Qin, X. Feng, Synlett 2004, 1077.
[48] M. G. Dekamin, S. Sagheb-Asl, M. R. Naimi-Jamal, Tetrahedron Lett.
2009, 50, 4063.
The partial financial support of this work by The Research
Council of Iran University of Science and Technology, Iran
(grant no. 160/5295) is gratefully acknowledged. We also thank
Dr Mohammad R. Jamali (Payame Noor University, Behshahr
Branch, Iran) for a gift of PBPDC.
References
[49] M. G. Dekamin, J. Mokhtari, M. R. Naimi-Jamal, Catal. Commun.
2009, 10, 582.
[1] J. M. Brunel, I. S. Holmes, Angew. Chem. Int. Ed. 2004, 43, 2752.
[2] R. J. H. Gregory, Chem. Rev. 1999, 99, 3649.
[3] N. H. Khan, R. I. Kureshy, S. H. R. Abdi, S. Agrawal, R. V. Jasra, Coord.
Chem. Rev. 2008, 252, 593.
[50] M. G. Dekamin, S. Javanshir, M. R. Naimi-Jamal, R. Hekmatshoar,
J. Mokhtari, J. Mol. Cat. A: Chem. 2008, 283, 29.
[51] M. G. Dekamin, M. Farahmand, S. Javanshir, M. R. Naimi-Jamal,
Catal. Commun. 2008, 9, 1352.
[52] A. Blanrue, R. Wilhelm, Synlett 2004, 2621.
[53] X. Wang, S. K. Tian, Tetrahedron Lett. 2007, 48, 6010.
[54] S. E. Denmark, W. Chung, J. Org. Chem. 2006, 71, 4002.
[55] S. K. Tian, R. Hong, L. Deng, J. Am. Chem. Soc. 2003, 125, 9900.
[56] I. V. P. Raj, G. Suryavanshi, A. Sudalai, Tetrahedron Lett. 2007, 48,
7211.
[57] M. G. Dekamin, Z. Karimi, J. Organomet. Chem. 2009, 694, 1789.
[58] B. M. Fetterly, J. G. Verkade, Tetrahedron Lett. 2005, 46, 8061.
[59] Z. Wang, B. M. Fetterly, J. G. Verkade, J. Organomet. Chem. 2002,
646, 161.
[60] I. Amurrio, R. Co´rdoba, A. G. Csa´ky, J. Plumet, Tetrahedron. 2004, 60,
10521.
[4] M. North, Tetrahedron 2004, 60, 10383.
[5] J. Gawronski, N. Wascinska, J. Gajewy, Chem. Rev. 2008, 108, 5227.
[6] W. P. Weber, Silicon Reagents for Organic Synthesis, Springer: Berlin,
1983.
[7] E. W. Colvin, Silicon Reagents in Organic Synthesis, Academic Press:
London, 1981.
[8] A. Heydari, L. Ma’Mani, Appl. Organomet. Chem. 2008, 22, 12.
[9] A. Majhi, S. S. Kim, H. S. Kim, Appl. Organomet. Chem. 2008, 22, 407.
[10] N. Azizi, M. R. Saidi, J. Organomet. Chem. 2003, 688, 283.
[11] H. Firouzabadi, N. Iranpoor, A. A. Jafari, J. Organomet. Chem. 2005,
690, 1556.
[12] N. Kurono, M. Yamaguchi, K. Suzuki, T. Ohkuma, J. Org. Chem. 2005,
70, 6530.
[13] J. Wang, Y. Masui, K. Watanabe, M. Onaka, Adv. Synth. Catal. 2009,
351, 553.
[61] J. J. Song, F. Gallou, J. T. Reeves, Z. Tan, N. K. Yee, C. H. Senanyake,
J. Org. Chem. 2006, 71, 1273.
[62] Y. Suzuki, M. D. Abu Bakar, K. Muramatsu, M. Sato, Tetrahedron
2006, 62, 4227.
[63] Y. Fukuda, Y. Maeda, S. Ishii, K. Kondo, T. Aoyama, Synthesis 2006,
589.
[64] X. Wang, S. K. Tian, Synlett 2007, 1416.
[65] For a recent review on Lewis base catalysis, see: S. E. Denmark,
G. L. Beutner, Angew. Chem. Int. Ed. 2008, 47, 1560.
[66] S. T. Kadam, S. S. Kim, Catal. Commun. 2008, 9, 1342.
[67] L. Wang, X. Huang, J. Jiang, X. Liu, X. Feng, Tetrahedron Lett. 2006,
47, 1581.
[14] M. L. Kantam, S. Laha, J. Yadav, B. M. Choudary, B. Sreedhar, Adv.
Synth. Catal. 2006, 348, 867.
[15] S. Kataoka, A. Endo, A. Harada, Y. Inagi, T. Ohmori, Appl. Catal. A:
Gen. 2008, 342, 107.
[16] S. K. De, R. A. Gibbs, J. Mol. Catal. A: Chem. 2005, 232, 123.
[17] L. Mei, S. W. Wong, H. K. Liang, W. S. Xuan, Appl. Organomet. Chem.
2008, 22, 181.
[18] S. C. George, S. S. Kim, S. T. Kadam, Appl. Organomet. Chem. 2007,
21, 994.
[19] W. K. Cho, J. K. Lee, S. M. Kang, Y. S. Chi, H. Lee, I. S. Choi, H. S. Lee,
Chem. Eur. J. 2007, 13, 6351.
[68] S. J. Zuend, E. N. Jacobsen, J. Am. Chem. Soc. 2007, 129, 15872.
c
www.interscience.wiley.com/journal/aoc
Copyright ꢀ 2009 John Wiley & Sons, Ltd.
Appl. Organometal. Chem. 2010, 24, 229–235

Organocatalytic synthesis of cyanohydrin trimethylsilyl ethers
[69] R. M. Steele, C. Monti, C. Gennari, U. Piarulli, F. Andreoli,
N. Vanthuyne, C. Roussel, Tetrahedron: Asymmetry 2006, 17, 999.
[70] S. C. George, S. S. Kim, G. Rajagopal, Appl. Organomet. Chem. 2007,
21, 798.
[71] X. Liu, B. Qin, X. Zhou, B. He, X. Feng, J. Am. Chem. Soc. 2005, 127,
12224.
[77] M. Andac, A. Asan, I. Isildak, H. Cesur, Anal. Chim. Acta 2001, 434,
143.
[78] Y. Liu, W. Bao, Tetrahedron Lett. 2007, 48, 4785.
[79] S. Sharma, F. Rashid, B. Bano, J. Agric. Food Chem. 2005, 53, 6027.
[80] J. A. Vale, W. M. Faustino, P. H. Menezes, G. F. de Sa´, Chem.Commun.
2006, 3340.
[72] J. Cookson, P. D. Beer, Dalton Trans. 2007, 1459.
[73] A. Donzelli, P. G. Potvin, Inorg. Chem. 2009, 48, 4171.
[81] J. A. Vale, W. M. Faustino, P. H. Menezes, G. F. de Sa´, J. Braz. Chem.
Soc. 2006, 17, 829.
[74] For
a
review, see: A. Gonzalvez, M. L. Cervera, S. Armenta,
[82] F. A. Nasirov, Petrol. Chem. 2001, 41, 369.
[83] P. J. Nieuwenhuizen, A. W. Ehlers, J. G. Haasnoot, S. R. Janse,
J. Reedijk, E. J. Baerends, J. Am. Chem. Soc. 1999, 121, 163.
[84] M. S. Khajavi, M. G. Dakamin, H. Hazarkhani, J. Chem. Res. (S) 2000,
145.
M. Guardia, Anal. Chim. Acta 2009, 636, 129.
[75] M. R. Jamali, Y. Assadi, F. Shemirani, Separat. Sci. Technol. 2007, 42,
3503.
[76] E. Z. Jahromi, A. Bidari, Y. Assadi, M. R. Millani Hosseini, Anal. Chim.
Acta 2007, 585, 305.
c
Appl. Organometal. Chem. 2010, 24, 229–235
Copyright ꢀ 2009 John Wiley & Sons, Ltd.
www.interscience.wiley.com/journal/aoc