Cyanosilylation of aldehydes and ketones catalyzed by nanocrystalline magnesium oxide

Article abstract of DOI:10.1080/00397910802238791

Cyanosilylation of various aldehydes and ketones with TMSCN proceeded smoothly under mild conditions to give the corresponding cyanohydrin trimethylsilyl ethers in the presence of nanocrystalline magnesium oxide. The cyanohydrin trimethylsilyl ethers of aldehydes produced cyanohydrins in good to high yields on treatment with 2 N HCl. 29Si NMR spectral evidence proved that the reaction proceeds through the hypervalent silicate species by coordination to O2-/O- (Lewis basic site) of nanocrystalline magnesium oxide. Copyright Taylor & Francis Group, LLC.

Full text of DOI:10.1080/00397910802238791

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Cyanosilylation of Aldehydes
and Ketones Catalyzed by
Nanocrystalline Magnesium
Oxide
M. Lakshmi Kantam a , Koosam Mahendar a , Bojja
Sreedhar a , K. Vijay Kumar a & B. M. Choudary b
a Inorganic and Physical Chemistry Division, Indian
Institute of Chemical Technology , Hyderabad , India
b Ogene Systems (I) Pvt. Ltd , Hyderabad , India
Published online: 20 Oct 2008.
To cite this article: M. Lakshmi Kantam , Koosam Mahendar , Bojja Sreedhar , K. Vijay
Kumar & B. M. Choudary (2008) Cyanosilylation of Aldehydes and Ketones Catalyzed
by Nanocrystalline Magnesium Oxide, Synthetic Communications: An International
Journal for Rapid Communication of Synthetic Organic Chemistry, 38:22, 3919-3936,
DOI: 10.1080/00397910802238791
To link to this article: http://dx.doi.org/10.1080/00397910802238791
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Synthetic Communications1, 38: 3919–3936, 2008
Copyright # Taylor & Francis Group, LLC
ISSN: 0039-7911 print=1532-2432 online
DOI: 10.1080/00397910802238791
Cyanosilylation of Aldehydes and Ketones
Catalyzed by Nanocrystalline Magnesium Oxide
M. Lakshmi Kantam,1 Koosam Mahendar,1 Bojja Sreedhar,1
K. Vijay Kumar,1 and B. M. Choudary2
1Inorganic and Physical Chemistry Division, Indian Institute of Chemical
Technology, Hyderabad, India
2Ogene Systems (I) Pvt. Ltd, Hyderabad, India
Abstract: Cyanosilylation of various aldehydes and ketones with TMSCN
proceeded smoothly under mild conditions to give the corresponding cyanohydrin
trimethylsilyl ethers in the presence of nanocrystalline magnesium oxide. The
cyanohydrin trimethylsilyl ethers of aldehydes produced cyanohydrins in good
to high yields on treatment with 2 N HCl. 29Si NMR spectral evidence proved
that the reaction proceeds through the hypervalent silicate species by coordina-
tion to O2ꢀ=Oꢀ (Lewis basic site) of nanocrystalline magnesium oxide.
Keywords: Aldehydes, cyanohydrins, cyanohydrin trimethylsilyl ethers, cyano-
silylation, ketones, nanocrystalline magnesium oxide, trimethylsilyl cyanide
INTRODUCTION
The cyanation reaction of carbonyl compounds is one of the most impor-
tant methods to obtain polyfunctional molecules in organic synthesis.[1]
Cyanohydrins or cyanohydrin trimethylsilyl ethers are highly versatile
synthetic intermediates, which can be easily converted into a-hydroxy
carbonyl derivatives, b-amino alcohols, and a-amino acids[2] for their
application in pharmaceuticals and agrochemicals.[3]
Received April 18, 2008.
Address correspondence to M. Lakshmi Kantam, Inorganic and Physical
Chemistry Division, Indian Institute of Chemical Technology, Hyderabad
500 007, India. E-mail: mlakshmi@iict.res.in
3919

3920
M. L. Kantam et al.
Generally, cyanohydrins are prepared by the interaction of carbonyl
compounds with a cyanide source serving as nucleophile. Several useful
cyanating reagents have been reported in the literature;[4] among them,
trimethylsilyl cyanide (TMSCN) seems to be one of the most effective,
safe, and easy to handle cyanating sources for the nucleophilic addition
to carbonyl compounds. A variety of catalysts have been used to promote
the cyanosilylation reactions, such as Lewis acids;[5] Lewis bases;[6]
nonionic bases;[7] N-heterocyclic carbenes;[8] V-, Mn-, Al-, and Ti-salen
complexes;[9] and organic=inorganic salts.[10] In recent years, many
researchers have developed various catalysts[11] such as oxazaboro-
lidinium ion, amino-thiourea, chiral Ti-TADDOLs that have been suc-
cessfully applied in asymmetric cyanosilylation reactions. Shibasaki
et al. designed Ti, Al-phosphine oxide bifunctional catalysts[12] using
carbohydrate or binaphthol as scaffolds, and Feng et al. developed Ti,
Al-N-oxide bifunctional catalysts[13] using various chiral ligands includ-
ing proline, pyrrolidine and 1,2-diamino compounds for the asymmetric
cyanosilylation reactions. However, there are some reports of cyanosily-
lation reaction using reusable solid acid, solid base catalysts and ionic
liquids as heterogeneous catalysts.[14]
Nanocrystalline metal oxides find excellent applications as active
adsorbents for gases, for destruction of hazardous chemicals,[15] and as
catalysts for various organic transformations.[16] These high reactivities
are due to high surface area combined with unusually reactive morphol-
ogies. In continuation of our work on nanomaterials, herein we report an
effective cyanosilylation of aldehydes and ketones to give cyanohydrins
by using nanocrystalline magnesium oxide (NAP-MgO) catalyst. The
cyanohydrin trimethylsilyl ethers of aldehydes afforded cyanohydrins in
good to high yields on treatment with 2 N HCl (Scheme 1).
Scheme 1. NAP-MgO catalyzed cyanosilylation reaction between aldehydes or
ketones and TMSCN. 3a with TMSCN catalyzed by NAP-MgO. Reaction con-
ditions: benzaldehyde 1a or acetophenone 3a (1 mmol), TMSCN (1.5 mmol for
1a, 2 mmol for 3a), NAP-MgO (0.1 g), and solvent (3 mL) at room temperature.

Cyanosilylation of Aldehydes and Ketones
RESULTS AND DISCUSSION
3921
To understand the relationship between structure and reactivity, various
forms of magnesium oxide crystals CM-MgO (commercial MgO, SSA:
30 m2=g), NA-MgO (NanoActive MgO, conventionally prepared MgO,
SSA: 250 m2=g), NAP-MgO (NanoActive plus MgO, aerogel-prepared
MgO, SSA: 590 m2=g)] were initially evaluated in the cyanosilylation
reaction between acetophenone 3a and TMSCNat room temperature.
All these MgO crystals catalyze the cyanosilylation reaction in quantita-
tive yields. However, NAP-MgO was more active than NA-MgO and
CM-MgO in the cyanosilylation reaction (Table 1, entry 1).
Initially, we optimized the reaction with benzaldehyde 1a and
acetophenone 3a as model substrates with TMSCN using NAP-MgO
at room temperature (Table 1). Various solvents such as CH2Cl2, N,N-
dimethylformamide (DMF), tetrahydrofuran (THF), CHCl3, MeOH,
and toluene were screened for the reaction between acetophenone 3a
Table 1. Optimization of cyanosilylation reaction of benzaldehyde 1a or
acetophenone 3a with TMSCN catalyzed by NAP-MgO
Entry
Substrate
Solvent
THF
Time (h)
Yield (%)a
1
2
3
3a
1a
3a
1a
3a
1a
3a
3a
3a
4,7b, 12,c 8,d 5e 12f
92, 87,b 85,c 81,d 88,e 0f
2
5
3
6
3
8
10
12
93
89
86
86
81
78
71
N.R
CH2Cl2
DMF
4
5
6
CHCl3
PHCH3
CH3OH
aIsolated yield.
bNA-MgO.
cCM-MgO.
dSil-NAP-MgO.
eFourth cycle.
fWithout catalyst.

3922
M. L. Kantam et al.
and TMSCN. A study on the solvent effect showed that THF provided
the best yields of cyanohydrin trimethylsilyl ether 4a (entry 1), whereas
no product was observed with MeOH (entry 6). When the reaction
between benzaldehyde 1a and TMSCN was carried out in THF in the
presence of NAP-MgO, the product cyanohydrin trimethylsilyl ether 2a
was obtained in higher yields than in CH2Cl2, DMF (Table 1, entries
1–3).
The cyanosilylated products obtained from aldehydes and TMSCN
in the presence of NAP-MgO were further treated with 2 N HCl and
afforded the corresponding cyanohydrins 5 as summarized in Table 2.
As can be seen from Table 2, benzaldehyde, benzaldehydes bearing
electron-withdrawing as well as electron-donating substituents, furfural-
dehyde, and naphthaldehyde gave their corresponding cyanohydrins in
good to high yields (entries 1–9), whereas 4-N,N-dimethyl benzaldehyde
gave its cyanohydrin product in 72% of isolated yields (entry 14). Cinna-
maldehyde produced the 1,2-addition product regioselectively, without
formation of any 1,4-adduct (entry 10). The reaction of aliphatic alde-
hydes with TMSCN formed the corresponding cyanohydrins in good
yields (entries 11–13).
As shown in Table 3, the reaction of aromatic, aliphatic, and hetero-
cyclic ketones with TMSCN in the presence of NAP-MgO proceeded
smoothly at room temperature to give the corresponding cyanohydrin tri-
methylsilyl ethers 4 in good to high yields. Highly conjugated naphthones
gave their cyanosilylated products in yields comparable to other aromatic
compounds (entries 7 and 8). Similar to aldehydes, a,b-unsaturated
ketone (benzylideneacetone) reacted with TMSCN in the presence of
NAP-MgO and afforded the 1,2-addition product regioselectively, rather
than the 1,4-adduct (entry 9). It is noteworthy that ketones such as cyclo-
hexanone, benzophenone, and a-tetralone took longer times for comple-
tion of the reaction under the optimized conditions (entries 10–12). This
may be due to the steric hindrance of their reactive keto group.
As to the mechanism, there was no reaction between 1 or 3 and
TMSCN without an NAP-MgO catalyst, which indicates that the catalyst
is essential for the reaction (Table 1, entry 1). It was suggested that on the
basis of proposed mechanism in our previous work,[16g] we assume that
the cyanation of carbonyl compounds 1 or 3 with TMSCN proceeds
through the formation of an active intermediate, hypervalent silicate I
coordinated with the NAP-MgO in the present system as illustrated in
Scheme 2.[6d,7b,16g,17] Trimethylsilyl cyanide is activated by O2ꢀ=Oꢀ
(Lewis base) of NAP-MgO catalyst to form a hypervalent silicate I and
coordinates with O2ꢀ=Oꢀ of the catalyst, polarizing the cyanide group
to become more reactive. Meanwhile, carbonyl compound 1 or 3 is
activated by Mg2þ=Mgþ (Lewis acid) of NAP-MgO. The highly reactive

Cyanosilylation of Aldehydes and Ketones
3923
Table 2. Synthesis of various cyanohydrins by using NAP-MgOa
Entry
1
R
Product 5
Time (h)
2
Yield (%)b
90
Ph
2
4-OCH3-Ph
3
89
3
4
4-CH3-Ph
3
4
81
82
3,4,5-OCH3-Ph
5
6
4-Cl-Ph
3
2
82
76
4-CN-Ph
7
8
3-CF3-Ph
Furfuryl
4
3
84
86
(Continued )

3924
M. L. Kantam et al.
Table 2. Continued
Entry
R
Product 5
Time (h)
Yield (%)b
9
2-Naphthyl
4
3
88
10
Cinnamyl
82
11
12
Cyclohexyl
CH3-(CH2)5
5
4
79
84
ꢀ
ꢀ
13
14
Ph-(CH2)2
4
3
84
72
4-N(CH3)2ꢀPh
aReaction conditions: (i) aldehyde 1 (1 mmol), TMSCN (1.5 mmol), NAP-MgO
(0.1 g), and THF (3 mL) at room temperature; (ii) 2N HCl (2 mL) at room tem-
perature.
bIsolated yield.
cyanide ion attacks the carbonyl carbon and the trimethylsilyl group
attacks the carbonyl oxygen, resulting in the formation of the silylated
product 2 or 4.
To confirm the hypothesis of hypervalent silicate intermediate I, 29Si
[17]
NMR (400-MHz) analyses were carried out at 25 ꢁC in CDCl3
using
tetramethylsilane as an internal standard. All the experiments were
performed in CDCl3, as detailed in the experimental procedure. As
illustrated in Table 4, entry 1, TMSCN affords a signal at d ¼ ꢀ11.45 ppm

Cyanosilylation of Aldehydes and Ketones
3925
Table 3. Cyanosilylation reaction of various ketones with TMSCN catalyzed by
NAP-MgOa
Time Yield
(%)b
Entry
1
R1, R2
Product 4
(h)
Ph, CH3
4
92
2
4-OCH3-Ph, CH3
6
88
3
4
4-CH3-Ph, CH3
4-NO2-Ph, CH3
5
4
87
91
5
6
4-Cl-Ph, CH3
Furfuryl, CH3
4
6
85
81
7
8
2-Naphthyl, CH3
4
5
90
89
(6-OMe)-2-Naphthyl, CH3
(Continued )

3926
M. L. Kantam et al.
Table 3. Continued
Time Yield
(%)b
Entry
9
R1, R2
Product 4
(h)
Cinnamyl, CH3
5
85
ꢀ
10
11
ꢀ(CH2)5
8
7
81
89
Ph, Ph
12
a-Tetralone
8
86
aReaction conditions: acetophenone 3 (1 mmol), TMSCN (2 mmol), NAP-
MgO (0.1 g), and THF (3 mL) at room temperature.
bIsolated yield.
(lit.[17]: d ¼ ꢀ11.5). When TMSCN is added to the solution of
NAP-MgO, another signal was found at d ¼ 7.07 ppm (lit.[17]
:
d ¼ 7.1 ppm) (Table 4, entry 2). The spectral changes strongly indicate
Scheme 2. Plausible mechanism for the cyanosilylation reaction using
NAP-MgO.

Cyanosilylation of Aldehydes and Ketones
3927
Table 4. 29Si NMR chemical shifts of several systemsa
Entry
Components
d (ppm)
1
2
3
4
TMSCN
TMSCN þ NAP-MgO
ꢀ11.45
7.07, ꢀ11.45
7.05, ꢀ11.43
7.28, ꢀ11.52
TMSCN þ Sil-NAP-MgO
TMSCN þ NAP-MgO þ acetophenone
aReaction conditions: acetophenone 3a (0.1 mmol), TMSCN (0.2 mmol), cata-
lyst (0.01 g), and CDCl3 (0.5 mL) at 25 ꢁC.
that the environments around the silicon atoms of some TMSCN species
are changed because of NAP-MgO. It is possible that these silicon atoms
of TMSCN could form five- or six-coordinated hypervalent silicate
species by coordination to O2ꢀ=Oꢀ (Lewis basic site) of NAP-MgO,
but not the Brønsted basic site (Scheme 2).[18] This is proven, when
TMSCN is added to the solution of Sil-NAP-MgO; an identical spectrum
is observed with a signal at d ¼ 7.05 ppm as in NAP-MgO (Table 5, entry
3). When acetophenone is added to the solution of NAP-MgO and
TMSCN, an almost identical spectrum is observed (Table 4, entry 4),
which clearly suggests that the hypervalent silicate also exists. The little
difference observed between its transition state and that of entry 2,
according to the chemical shift, may be due to the coordination involve-
ment of the carbonyl oxygen of ketone.
To understand the relationship between structure and reactivity of
the catalyst in the cyanosilylation reaction, it is important to know the
structure and nature of the reactive sites of NAP-MgO. NAP-MgO has
a single-crystallite, three-dimensional polyhedral structure, which poses-
ses high surface concentrations of edge=corner and various exposed crys-
tal planes (such as 002, 001, 111), leading to inherently high surface
reactivity per unit area. Thus, NAP-MgO indeed displayed the highest
activity compared to that of NA-MgO and CM-MgO. Besides this, the
NAP-MgO has Lewis acid sites Mg2þ, Lewis basic sites O2ꢀ and Oꢀ,
lattice-bound and isolated Brønsted hydroxyls, and anionic and cationic
vacancies.[18] Cyanosilylation reactions are known to be driven by base
catalysts,[6] and accordingly, the surface –OH, O2ꢀ, and Oꢀ sites of these
oxide crystals are expected to trigger these reactions. To examine the role
of –OH, the Sil-NAP-MgO[18e] devoid of free –OH were tested in cyano-
silylation reactions. It was found that the rate of the reaction was slow
and required longer reaction time (Table 1, entry 1). Although both
NAP-MgO and NA-MgO possess defined shapes and the same average
concentrations of surface –OH groups, a possible rationale for the

3928
M. L. Kantam et al.
display of higher reactivity to cyanohydrin trimethylsilyl ethers by the
NAP-MgO is that the presence of more surface Lewis acid sites Mg2þ
ions (21%) and –OH groups present on the edge and corner sites on
the NAP-MgO, which are stretched in three-dimensional space, are more
isolated and accessible for the reactants. Thus, NAP-MgO displays the
highest activity compared to NA-MgO and CM-MgO. In the cyanosilyla-
tion reaction, O2ꢀ=Oꢀ (Lewis base) of NAP-MgO activates the trimethyl-
silyl cyanide, which forms a hypervalent silicate, and coordinates with
O2ꢀ=Oꢀ of the NAP-MgO. The cyanosilylation reaction proceeds via
dual activation of both substrates (electrophiles and nucleophiles) by
NAP-MgO. Thus, the Lewis base moiety (O2ꢀ=Oꢀ) of the catalyst acti-
vates the TMSCN, and the Lewis acid moiety (Mg2þ=Mgþ) activates
the aldehyde or ketone (Scheme 2).[12,13]
The NAP-MgO was reused for four cycles with consistent activity
(Table 1, entry 1). After completion of the reaction, the catalyst was
centrifuged and washed properly several times. The recovered catalyst
was activated at 250ꢁC for 1 h under a nitrogen atmosphere, before reuse.
In conclusion, nanocrystalline MgO is demonstrated to be an effective
catalyst for the cyanation of aldehydes as well as ketones to afford the cor-
responding cyanohydrin trimethylsilyl ethers in good to high yields.
Further, the cyanohydrin trimethylsilyl ethers obtained from aldehydes
on treatment with 2 N HCl afforded cyanohydrins in good to high yields.
EXPERIMENTAL
General Remarks
Nanocrystalline MgO samples were obtained from Nanoscale Materials,
Inc. (formerly Nantek, Inc.), Manhattan, Kansas, USA. All catalysts are
calcined at 400 ꢁC for 4 h before use. All chemicals were purchased from
Aldrich Chemicals and S.D. Fine Chemicals, Pvt. Ltd., India, and used as
received. All solvents were used laboratory reagent (LR) grade and used
as received from S.D. Fine Chemicals Pvt. Ltd, India. ACME silica gel
(100–200 mesh) was used for column chromatography, and thin-layer
chromatography (TLC) was performed on Merck precoated silica gel
60-F254 plates. Melting points were measured in open capillary tubes
and are uncorrected. The IR spectra of all compounds were recorded
on a Nexus 670 Fourier transform infrared (FTIR) spectrometer (Necolet
Corporation Ltd., USA) using KBr pellets or neat. The IR values are
reported in reciprocal centimeters (cmꢀ1). The 1H and 13C NMR spectra
were recorded on Varian-Gemini 200-MHz and Bruker-Avance 300-MHz
spectrometers. The 29Si NMR spectra were recorded on a Varian-Unity

Cyanosilylation of Aldehydes and Ketones
3929
400-MHz spectrometer. Chemical shifts (d) are reported in parts per
million (ppm), using TMS (d ¼ 0) as an internal standard in CDCl3. All
the mass spectra were recorded on a GC-MS QP 2010 Plus (Shimadzu
Corporation, Japan) and QSTAR XL high resolution mass spectrometer
(Applied Biosystems, Foster City, USA).
Typical Procedure for the Synthesis of Cyanohydrins from Aldehydes
TMSCN (1.5 mmol) was added in one portion to a stirred solution of
NAP-MgO (0.1 g) in THF (3 mL) at ambient temperature. After 5 min,
aldehyde 1 (1 mmol) was added to the reaction mixture and stirred at
room temperature. After completion of the reaction (as monitored by
TLC), the reaction mixture was centrifuged to separate the catalyst.
The catalyst was washed with THF (3 ꢂ 4 mL), and 2 mL of 2 N HCl
was added to the combined THF solution and stirred for 1 h at room
temperature. Ethyl acetate and water were added to this, and the product
was extracted with ethyl acetate and washed with saturated sodium bicar-
bonate solution, followed by brine solution and water. The combined
organic phase was removed under reduced pressure, and the crude pro-
duct was purified by column chromatography on silica gel (60–120 mesh)
using hexane=ethyl acetate in varying proportions as an eluent to afford
the pure cyanohydrin product 5. The spectroscopic data including IR,
NMR, and mass spectra of the products were identical to those of
authentic samples. The physical data and the spectroscopic data of
selected cyanohydrins reported in Table 2 are given here.
Typical Procedure for the Synthesis of Cyanohydrin Trimethylsilyl
Ethers from Ketones
TMSCN (2 mmol) was added to a stirred solution of NAP-MgO (0.1 g) in
THF (3 mL) in one portion at ambient temperature. After 5 min, ketone 3
(1 mmol) was added to the reaction mixture and stirred at room tempera-
ture. After completion of the reaction (as monitored by TLC), the reac-
tion mixture was centrifuged, and the catalyst was washed several times
with ethyl acetate. The centrifugate was concentrated under reduced pres-
sure to afford the crude product, which after flash chromatography on
silica gel (60–120 mesh) using hexane=ethyl acetate (9:1) afforded the pure
product 4. The spectroscopic data including NMR and mass spectra of
the products were identical to those of authentic samples. The physical
data and the spectroscopic data of selected cyanohydrin trimethylsilyl
ethers reported in Table 3 are given here.

3930
M. L. Kantam et al.
DATA
2-Hydroxy-2-(3,4,5-trimethoxy Phenyl) Acetonitrile (Entry 4, Table 2)
Brown solid; mp 93–95 ꢁC; IR (KBr): 2248, 3359 cmꢀ1; 1H NMR (CDCl3,
200 MHz): d 3.2 (d, J ¼ 7.4 Hz, 1H), 3.8 (s. 3H), 3.86 (s, 6H), 5.39 (d,
J ¼ 7.4 Hz, 1H), 6.65 (s, 2H); 13C NMR (CDCl3, 75 MHz): d 56.1, 60.8,
63.4, 103.5, 118.9, 131.2, 138.2, 153.3; EI-MS: Mþ. (%): 223 (8), 196
(100), 181 (50), 165 (8).
2-Hydroxy-4-phenyl-3-butenenitrile (Entry 10, Table 2)
1
Pale yellow solid; mp 73–74 ꢁC; IR (KBr): 3360, 2250, cmꢀ1; H NMR
(CDCl3, 300 MHz): d 2.74 (s, br, 1H), 5.12 (s, br, 1H), 6.24 (dd, J ¼ 5.3,
15.9 Hz, 1H), 6.91 (d, J ¼ 15.9 Hz, 1H), 7.29–7.42 (m, 5H); 13C NMR
(CDCl3, 75 MHz): d 61.8, 118.2, 122.2, 127.0, 128.8, 129.0, 134.7, 135.3;
EI-MS: Mþ (%): 159 (38), 132 (27), 131 (75), 115 (39), 103 (60), 77 (78).
2-Cyclohexyl-2-hydroxy Acetonitrile (Entry 11, Table 2)
Colorless oil; IR (neat): 3440, 2246 cmꢀ1; 1H NMR (CDCl3, 300 MHz): d
1.07–1.38 (m, 5H), 1.7–1.91 (m, 6H), 3.38 (s, br, 1H), 4.24 (d, J ¼ 6.0 Hz,
1H); 13C NMR (CDCl3, 75 MHz): d 25.3, 25.8, 27.8, 28.1, 42.1, 66.1,
119.4; ESI-MS: m=z 157 [M þ NH4]þ.
2-Hydroxy-4-phenyl-butyronitrile (Entry 13, Table 2)
Colorless oil; IR (neat): 3477, 2245 cmꢀ1; 1H NMR (CDCl3, 300 MHz): d
2.06–2.2 (m, 2H), 2.81 (t, J ¼ 8.3 Hz, 2H), 3.38 (s, br, 1H), 4.34 (q, 1H),
7.15–7.29 (m, 5H); 13C NMR (CDCl3, 75 MHz): d 30.5, 36.4, 60.1, 120.0,
126.4, 128.4, 128.6, 139.5; EI-MS: Mþ (%): 161 (6), 134 (19), 105 (38), 91
(100), 77 (35).
(4-N,N-Dimethylamino-phenyl)-hydroxy-acetonitrile (Entry 14, Table 2)
Brown solid; mp 110–112 ꢁC; IR (KBr): 3433, 2251 cmꢀ1 1H NMR
;
(CDCl3, 300 MHz): d 2.16 (d, J ¼ 6.4 Hz, 1H), 2.98 (s, 6H), 5.38 (d,
J ¼ 6.4 Hz, 1H), 6.69 (d, J ¼ 8.9 Hz, 2H), 7.35 (d, J ¼ 8.9 Hz, 2H); 13C
NMR (CDCl3, 75 MHz): d 40.3, 63.7, 112.4, 119.1, 122.8, 128.1, 151.4;
ESI-MS: m=z 177 [M þ H]þ; HRMS (ESI): Anal. calcd. for
C10H13N2O: 177.1027, found : 177.1034.

Cyanosilylation of Aldehydes and Ketones
3931
2-Trimethyl Silyloxy-2-(40-methyl Phenyl)propanenitrile (Entry 3, Table 3)
Colorless oil; 1H NMR (CDCl3, 300 MHz): d 0.19 (s, 9H), 1.84 (s, 3H), 2.4
(s, 3H), 7.19 (d, J ¼ 8.3 Hz, 2H), 7.42 (d, J ¼ 8.3 Hz, 2H); 13C NMR
(CDCl3, 75 MHz): d 1.0, 21.0, 33.5, 71.5, 121.7, 124.5, 129.2, 138.5, 139.0;
EI-MS: Mþ (%): 233 (82), 218 (100), 207 (13), 161 (18), 146 (35), 119 (35).
2-Trimethylsilyloxy-2-(furan-2-yl)-propanenitrile (Entry 6, Table 3)
1
Colorless oil; H NMR (CDCl3, 300 MHz): d 0.19 (s, 9H), 2.09 (s, 3H),
6.4 (dd, J ¼ 2.3, 3.8 Hz, 1H), 6.6 (d, J ¼ 3.8 Hz, 1H), 7.53 (s, 1H); 13C
NMR (CDCl3, 75 MHz): 0.5, 28.9, 65.9, 108.1, 110.7, 120.2, 143.1,
151.6; EI-MS: Mþ (%): 209 (12), 194 (100), 167 (32), 110 (32).
2-Trimethylsilyloxy-2-(6-methoxy-2-naphthyl)-propanenitrile
(Entry 8, Table 3)
White solid; mp 79–81 ꢁC; 1H NMR (CDCl3, 300 MHz): d ¼ 0.16 (s, 9H),
1.91 (s, 3H), 3.92 (s, 3H), 7.08 (d, J ¼ 2.3 Hz, 1H), 7.15 (dd, J ¼ 2.3,
9.1 Hz, 1H), 7.53 (dd, J ¼ 2.3, 9.1 Hz, 1H), 7.73 (t, J ¼ 8.3 Hz, 2H), 7.91
(s, 1H);13C NMR (CDCl3, 75 MHz): 1.1, 33.4, 55.3, 71.8, 105.6, 119.5,
121.7, 122.9, 123.6, 127.5, 128.2, 129.8, 134.4, 136.9, 158.4; EI-MS: Mþ
(%): 299 (26), 284 (35), 200 (4), 185 (100).
2-Trimethylsilyloxy-2-methyl-4-phenyl-but-3-enenitrile (Entry 9, Table 3)
1
Colorless oil; H NMR (CDCl3, 300 MHz): d 0.24 (s, 9H), 1.73 (s, 3H),
6.02 (d, J ¼ 15.9 Hz, 1H), 6.85 (d, J ¼ 15.9 Hz, 1H), 7.24–7.39 (m, 5H);
13C NMR (CDCl3, 75 MHz):1.3, 30.8, 69.9, 120.6, 126.8, 128.5, 128.7,
129.5, 130.9, 135.0; EI-MS: Mþ (%): 245 (36), 230 (44), 146 (37), 131
(96), 115 (50), 103 (76).
ACKNOWLEDGMENTS
K. M. thanks Council of Scientific and Industrial Research, India, for the
award of his senior research fellowship. The authors thank Dr. A. V. S.
Sharma, NMR Division, Indian Institute of Chemical Technology, for
providing the 29Si NMR.

3932
M. L. Kantam et al.
REFERENCES
1. (a) Geregory, R. J. H. Cyanohydrins in nature and the laboratory: Biology,
preparations, and synthetic applications. Chem. Rev. 1999, 99, 3649–3682;
(b) Brunel, J.-M.; Holmes, I. P. Chemically catalyzed asymmetric cyanohy-
drin syntheses. Angew. Chem. Int. Ed. 2004, 43, 2752–2778; (c) Effenberger,
F. Synthesis and reactions of optically active cyanohydrins. Angew. Chem.
Int. Ed. 1994, 33, 1555–1564; (d) North, M. Synthesis and applications of
non-racemic cyanohydrins. Tetrahedron: Asymmetry 2003, 14, 147–176.
2. (a) North, M. Catalytic asymmetric cyanohydrin synthesis. Synlett 1993,
807–820; (b) Furin, G. G.; Vyazankin, O. A.; Gostevsky, B. A., Vyazankin,
N. S. Tetrahedron report number 234: Synthetic aspects of the use of organo-
silicon compounds under nucleophilic catalysis conditions. Tetrahedron 1988,
44, 2675–2749; (c) Rasmussen, J. K.; Hielmann, S. M.; Krepski, L. R. In
Advances in Silicon Chemistry; G. L. Larson (Ed.); JAI Press: London,
1991; vol. 1, p. 65; (d) Matthews, B. R.; Gountzos, H.; Jackson, W. R.;
Watson, K. G. Synthesis of threo-3-aryl-2,3-dihydroxypropanoic acid deriva-
tives with high optical purity. Tetrahedron Lett. 1989, 30, 5157–5158; (e)
Ziegler, T.; Horsch, B.; Effenberger, F. A convenient route to (R)-a-hydroxy
carboxylic acids and (2R)-1-amino-2-alkanols from (R)-cyanohydrins.
Synthesis 1990, 575–578; (f) Jackson, W. R.; Jacobs, H. A.; Matthews,
B. R.; Jayatilake, G. S.; Watson, K. G. Stereoselective syntheses of ephedrine
and related 2-aminoalcohols of high optical purity from protected cyanohy-
drins. Tetrahedron Lett. 1990, 31, 1447–1450; (g) Effenberger, F.; Stelzer,
U. Synthesis and stereoselective reactions of (R)-a-sulfonyl oxynitriles.
Angew. Chem. Int. Ed. 1991, 31, 873–874.
3. (a) Kusumoto, T.; Hanamoto, T.; Hiyama, Takehera, S.; Shoji, T.; Osawa,
T.; Kuriyama, T.; Nakamura, K.; Fujisawa, T. Optically active O-acyl
cyanohydrins as chiral dopants for ferro electric liquid crystals. Chem. Lett.
1990, 1615–1618; (b) Kruse, C. G. In Chirality in Industry; A. N. Collins,
G. Sheldrake, and J. Crosby (Eds.); Wiley: Chichester, 1992; chapter 14.
4. (a) Groutas, W. C.; Felker, D. Synthetic applications of cyanotrimethylsilane,
lodotrimethylsilane, azidotrimethylsilane, and methylthiotrimethylsilane.
Synthesis 1980, 861–868, and references cited therein; (b) Fujji, A.; Sakagu-
chi, S.; Ishii, Y. An efficient synthesis of dinitrile derivatives by the reaction
of oxime esters or acid anhydrides with cyanotrimethylsilane catalyzed by
La(Oi Pr)3. J. Org. Chem. 2000, 65, 6209–6212; (c) Kawasaki, Y.; Fujii, A.;
Nakano, Y.; Sakaguchi, S.; Ishii, Y. Acetylcyanation of aldehydes with acet-
one cyanohydrin and isopropenyl acetate by Cpꢃ Sm(thf)2. J. Org. Chem.
2
1999, 64, 4214–4216.
5. (a) Saravanan, P.; Anand, R. V.; Singh, V. R. Cu(OTf)2 catalyzed trimethyl-
silyl cyanide addition to carbonyl compounds. Tetrahedron Lett. 1998, 39,
3823–3824; (b) Yang, Y.; Wang, D. The addition of trimethylsilyl cyanide
to carbonyl compounds using Yb(OTf)3 as Lewis acid catalyst. Synlett
1997, 1379–1380; (c) Surya, K. D.; Richard, A. G. Vanadyl triflate as an effi-
cient and recyclable catalyst for trimethylsilyl cyanide addition to carbonyl
compounds. J. Mol. Catal. A: Chem. 2005, 232, 123–125; (d) Gassman, P. G.;

Cyanosilylation of Aldehydes and Ketones
3933
Talley, J. J. Cyanohydrins—A general synthesis. Tetrahedron Lett. 1978, 19,
3773–3776; (e) Curini, M.; Epifanio, M. C.; Rosati, O.; Rossi, M. Potassium
exchanged zirconium hydrogen phosphate as heterogenous catalyst in
cyanosilylation of carbonyl compounds. Synlett 1999, 315–316. (f) Greenlee,
W. J.; Hangauer, D. G. Addition of trimethylsilyl cyanide to a-
substituted ketones: Catalyst efficiency. Tetrahedron Lett. 1983, 24, 4559–
4560.
6. (a) Tian, S.-K.; Deng, L. A highly enantioselective chiral Lewis base–
catalyzed asymmetric cyanation of ketones. J. Am. Chem. Soc. 2001, 123,
6195–6196; (b) Tian, S.-K.; Hong, R.; Deng, L. Catalytic asymmetric cyano-
silylation of ketones with chiral Lewis base. J. Am. Chem. Soc. 2003, 125,
9900–9901; (c) Denmark, S. E.; Chung, W. Lewis base catalyzed addition
of trimethylsilyl cyanide to aldehydes. J. Org. Chem. 2006, 71, 4002–4005;
(d) Kobayashi, S.; Tsuchiya, Y.; Mukaiyama, T. A facile synthesis of cyano-
hydrin trimethylsilys ethers by the addition reaction of trimethylsilyl cyanide
with aldehydes under basic conditions. Chem. Lett. 1991, 537–540.
7. (a) Fetterly, B. M.; Verkade, J. G. P(RNCH2CH2)N: Efficient catalysts
for the cyanosilylation of aldehydes and ketones. Tetrahedron Lett. 2005,
46, 8061–8066; (b) Wang, Z.; Fetterly, B. M.; Verkade, J. G.
P(MeNMCH2CH2)3N: An effective catalyst for trimethylsilycyanation of
aldehydes and ketones. J. Org. Met. Chem. 2002, 646, 161–166.
8. (a) Song, J. J.; Gallou, F.; Reeves, J. T.; Tan, Z.; Yee, N. K.; Senanayake, C.
H. Activation of TMSCN by N-heterocyclic carbenes for facile cyanosilyla-
tion of carbonyl compounds. J. Org. Chem. 2006, 71, 1273–1276; (b) Suzuki,
Y.; Bakar, A.; Kazuyuki Muramastsu, M. D.; Sato, M. Cyanosilylation of
aldehydes catalyzed by N-heterocyclic carbenes. Tetrahedron 2006, 62,
4227–4231.
9. (a) Baleizao, C.; Gigante, B.; Garcia, H.; Corma, A. Vanadyl salen complexes
covalently anchored to an imidazolium ion as catalysts for the cyanosilylation
of aldehydes in ionic liquids. Tetrahedron Lett. 2003, 44, 6813–6816; (b)
Baleizao, C.; Gigante, B.; Garcia, H.; Corma, A. Ionic liquids as green
solvents for the asymmetric synthesis of cyanohydrins catalysed by VO(salen)
complexes. Green Chem. 2002, 4, 272–274; (c) Kim, S. S.; Lee, S. H.; Kwak,
J. M. Enantioselective cyanosilylation of ketones catalyzed by Mn(salen)=
Ph3PO. Tetrahedron: Asymmetry 2006, 17, 1165–1169; (d) Kim, S. S.; Song,
D. H. Asymmetric cyanohydrin synthesis catalyzed by Al(salen)=triphenyl-
phosphine oxide. Eur. J. Org. Chem. 2005, 1777–1780; (e) Belokon, Y. N.;
Green, B.; Ikonnikov, N. S.; North, M.; Tararov, V. I. The asymmetric
addition of trimethylsilyl cyanide to ketones catalysed by a bimetallic, chiral
(salen)titanium complex. Tetrahedron Lett. 1999, 40, 8147–8150.
10. (a) Jenner, G. Addition of trimethylsilyl cyanide to aromatic ketones pro-
moted by organic solutions of lithium salts. Tetrahedron Lett. 1999, 40,
491–494; (b) Kurono, N.; Yamaguchi, M.; Suzuki, K.; Ohkuma, T.
Lithium chloride: An active and simple catalyst for cyanosilylation of alde-
hydes and ketones. J. Org. Chem. 2005, 70, 6530–6532; (c) Amurrio, I.;
Cordoba, R.; Csaky, A. G.; Plumet, J. Tetrabutylammonium cyanide

3934
M. L. Kantam et al.
catalyzed diasteroselective cyanosilylation of chiral a-hydroxyketones. Tet-
rahedron 2004, 60, 10521–10524; (d) Raj, I. V. P.; Suryavanshi, G.;
Sudalai, A. Organocatalytic activation of TMSCN by basic ammonium
salts for efficient cyanation of aldehydes and imines. Tetrahedron Lett.
2007, 48, 7211–7214; (e) Liu, X.; Qin, B.; Zhou, X.; He, B.; Feng, X.
Catalytic asymmetric cyanosilylation of ketones by a chiral amino acid
salt. J. Am. Chem. Soc. 2005, 127, 12224–12225; (f) Wang, X.; Tian,
S.-K. Catalytic cyanosilylation of ketones with simple phosphonium salt.
Tetrahedron Lett. 2007, 48, 6010–6013.
11. (a) Ryu, D. H.; Corey, E. J. Highly enantioselective cyanosilylation of alde-
hydes catalyzed by a chiral oxazaborolidinium ion. J. Am. Chem. Soc. 2004,
126, 8106–8107; (b) Ryu, D. H.; Corey, E. J. Enantioselective cyanosilylation
of ketones catalyzed by a chiral oxazaborolidinium ion. J. Am. Chem. Soc.
2005, 127, 5384–5387; (c) Fuerst, D. E.; Jacobsen, E. N. Thiourea-catalyzed
enantioselective cyanosilylation of ketones. J. Am. Chem. Soc. 2005, 127,
8964–8965; (d) Zuend, S. J.; Jacobsen, E. N. Cooperative catalysis by tertiary
amino-thioureas: Mechanism and basis for enantioselectivity of ketone cya-
nosilylation. J. Am. Chem. Soc. 2007, 129, 15872–15883; (e) Brunel, J.-M.;
Legrand, O.; Buono, G. Enantioselective trimethylsilylcyanation of aromatic
aldehydes catalyzed by titanium alkoxide–chiral o-hydroxyarylphosphine
oxides complexes. Tetrahedron: Asymmetry 1999, 10, 1979–1984; (f) Kim,
S. S.; Kwak, J. M.; Rajagopal, G. Asymmetric cyanosilylation of aldehydes
by chiral Ti-TADDOL complex. Bull. Korean Chem. Soc. 2006, 27,
1638–1640.
12. (a) Kanai, M.; Hamashima, Y.; Shibasaki, M. Design of a new bifunctional
asymmetric catalyst from carbohydrates: Application to catalytic asymmetric
cyanosilylation of aldehydes and acetophenone. Tetrahedron Lett. 2000, 41,
2405–2409; (b) Mita, T.; Sasaki, K.; Kanai, M.; Shibasaki, M. Catalytic enan-
tioselective conjugate addition of cyanide to a,b-unsaturated N-acylpyrroles.
J. Am. Chem. Soc. 2005, 127, 514–515; (c) Hamashima, Y.; Sawada, D.;
Nogami, H.; Kanai, M.; Shibasaki, M. Highly enantioselective cyanosilyla-
tion of aldehydes catalyzed by a Lewis acid–Lewis base bifunctional catalyst.
Tetrahedron 2001, 57, 805–814; (d) Hamashima, Y.; Sawada, D.; Kanai, M.;
Shibasaki, M. A new bifunctional asymmetric catalysis: An efficient catalytic
asymmetric cyanosilylation of aldehydes. J. Am. Chem. Soc. 1999, 121,
2641–2642; (e) Hamashima, Y.; Kanai, M.; Shibasaki, M. Catalytic enantio-
selective cyanosilylation of ketones. J. Am. Chem. Soc. 2000, 122, 7412–7413.
13. (a) Shen, K.; Liu, X.; Li, Q.; Feng, X. Highly enantioselective cyanosilylation
of ketones catalyzed by a bifunctional Ti(IV) complex. Tetrahedron 2008, 64,
147–153; (b) Qin, B.; Liu, X.; Shi, J.; Zheng, K.; Zhao, H.; Feng, X. Enantio-
selective cyanosilylation of a,a-dialkoxy ketones catalyzed by proline-derived
in-situ-prepared N-oxide as bifunctional organocatalyst. J. Org. Chem. 2007,
72, 2374–2378; (c) Xiong, Y.; Huang, X.; Gou, S.; Huang, J.; Wen, Y.; Feng,
X. Enantioselective cyanosilylation of ketones catalyzed by a nitrogen-
containing bifunctional catalyst. Adv. Synth. Catal. 2006, 348, 538–544; (d)
Shen, Y.; Feng. X.; Li, Y.; Zhang, G.; Jiang, Y. A mild and efficient

Cyanosilylation of Aldehydes and Ketones
3935
cyanosilylation of ketones catalyzed by a Lewis acid–Lewis base bifunctional
catalyst. Tetrahedron 2003, 59, 5667–5675; (e) Chen, F.; Qin, B.; Feng, X.;
Zhang, G.; Jiang, Y. Enantioselective cyanosilylation of ketones catalyzed
by double-activation catalysts with N-oxides. Tetrahedron 2004, 60, 10449–
10460; (f) Chen, F.; Feng, X.; Qin, B.; Zhang, G.; Jiang, Y. Enantioselective
cyanosilylation of ketones by a catalytic double-activation method employing
chiral Lewis acid and achiral N-oxide catalysts. Org. Lett. 2003, 5, 949–952;
(g) Chen, F.; Zhou, H.; Liu, X.; Qin, B.; Feng, X.; Zhang, G.; Jiang, Y. Enan-
tioselective cyanosilylation of ketones by a catalytic double-activation
method with an aluminium complex and an N-oxide. Chem. Eur. J. 2004,
10, 4790–4797; (h) Shen, Y.; Feng, X.; Li, Y.; Zhang, G.; Jiang, Y. Asym-
metric cyanosilylation of ketones catalyzed by bifunctional chiral N-oxide
titanium complex catalysts. Eur. J. Org. Chem. 2004, 129–137.
14. (a) Kantam, M. L.; Sreekanth, P.; Santhi, P. L. Cyanosilylation of carbonyl
compounds catalyzed by a diamino-functionalised mesoporous catalyst.
Green Chem. 2000, 2, 47–48; (b) Shen, Z.-L.; Ji, S.-J.; Loh, T.-P. Ionic liquid
[omim][PF6] as an efficient and recyclable reaction media for the cyanosilyla-
tion of aldehydes without Lewis acid or any special activation. Tetrahedron
Lett. 2005, 46, 3137–3139; (c) Onaka, M.; Higuchi, K.; Suguta, K.; Izumi,
Y. Efficient solid catalyst system for cyanosilylation of carbonyl compounds
with cyano trimethylsilane. Chem. Lett. 1989, 1393–1396; (d) Higuchi, K.;
Onaka, M.; Izumi, Y. Efficient and regioselective cyanosilylation of cyclo-
hex-2-enone and other unsaturated ketones over solid acid and base catalysts.
J. Chem. Soc., Chem. Commun. 1991, 1035–1036; (e) Karimi, B.; Mani, L. M.
A highly efficient and recyclable silica-based scandium(III) interphase
catalyst for cyanosilylation of carbonyl compounds. Org. Lett. 2004, 6,
4813–4815; (f) Baleizao, C.; Gigante, B.; Garcia, H.; Corma. A. Vanadyl
salen complexes covalently anchored to single-wall carbon nanotubes as
heterogeneous catalysts for the cyanosilylation of aldehydes. J. Catal. 2004,
221, 77–84.
15. (a) Lucas, E.; Decker, S.; Khaleel, A.; Seitz, A.; Fultz, S.; Ponce, A.; Li, W.;
Carnes, C.; Klabunde, K. J. Nanocrystalline metal oxides as unique chemical
reagents=sorbents. Chem. Eur. J. 2001, 7, 2505–2510; (b) Schlogl, R.; Abd
Hamid, S. B. Nanocatalysis: Mature science revisited or something really
new? Angew. Chem. Int. Ed. 2004, 43, 1628–1637; (c) Bell, A. T. The impact
of nanoscience on heterogeneous catalysis. Science 2003, 299, 1688–1691; (d)
Carnes, C. L.; Klabunde, K. J.; Synthesis, isolation, and chemical reactivity
studies of nanocrystalline zinc oxide. Langmuir 2000, 16, 3764–3772;
(e) Klabunde, K. J.; Mulukutla, R. S. Nanoscale Materials in Chemistry;
Wiley Interscience: New York, 2001; chapter 7, p. 223.
16. (a) Choudary, B. M.; Kantam, M. L.; Ranganath, K. V. S.; Mahendar, K.;
Sreedhar, B. Bifunctional nanocrystalline MgO for chiral epoxy ketones via
Claisen–Schmidt condensation–asymmetric epoxidation reactions. J. Am.
Chem. Soc. 2004, 126, 3396–3397; (b) Choudary, B. M.; Ranganath, K. V.
S.; Pal, U.; Kantam, M. L.; Sreedhar, B. Nanocrystalline MgO for asym-
metric Henry and Michael reactions. J. Am. Chem. Soc. 2005, 127, 13167;

3936
M. L. Kantam et al.
(c) Choudary, B. M.; Ranganath, K. V. S.; Yadav, J.; Kantam, M. L. Synth-
esis of flavanones using nanocrystalline MgO. Tetrahedron Lett. 2005, 46,
1369–1371; (d) Choudary, B. M.; Mahendar, K.; Ranganath, K. V. S. Wads-
worth–Emmons reactions catalyzed by nanocrystalline MgO. J. Mol. Catal.
A: Chem. 2005, 234, 25–27; (e) Choudary, B. M.; Mahendar, K.; Kantam,
M. L.; Ranganath, K. V. S.; Athar, T. The one-pot Wittig reaction: A facile
synthesis of a,b-unsaturated esters and nitriles by using nanocrystalline
magnesium oxide. Adv. Synth. Catal. 2006, 348, 1977–1985; (f) Kantam, M.
L.; Ranganath, K. V. S.; Mahendar, K.; Chakrapani, L.; Choudary, B. M.
Asymmetric Michael addition of malonates to enones catalyzed by
nanocrystalline MgO. Tetrahedron Lett. 2007, 48, 7646–7649; (g) Kantam,
M. L.; Mahendar, K.; Sreedhar, B.; Choudary, B. M.Synthesis of a-amino
nitriles through Strecker reaction of aldimines and ketoimines by using nano-
crystalline magnesium oxide. Tetrahedron 2008, 64, 3351–3360.
17. Jiao, Z.; Feng, X.; Liu, B.; Chen., F.; Zhang, G.; Jiang, Y. Enantioselective
Strecker reactions between aldimines and trimethylsilyl cyanide promoted
by chiral N,N0-dioxides. Eur. J. Org. Chem. 2003, 3818–3826.
18. (a) Jeevanandam, P.; Klabunde, K. J. A study on adsorption of surfactant
molecules on magnesium oxide nanocrystals prepared by an aerogel route.
Langmuir 2002, 18, 5309–5313; (b) Richards, R.; Li, W.; Decker, S.; David-
son, C.; Koper, O.; Zaikovski, V.; Volodin, A.; Rieker, T.; Klabunde, K. J.
Consolidation of metal oxide nanocrystals: Reactive pellets with controllable
pore structure that represent a new family of porous, inorganic materials. J.
Am. Chem. Soc. 2000, 122, 4921–4925; (c) Utamapanya, S.; Klabunde, K. J.;
Schlup, J. R. Nanoscale metal oxide particles=clusters as chemical reagents:
Synthesis and properties of ultrahigh surface area magnesium hydroxide
and magnesium oxide. Chem. Mater. 1991, 3, 175–181; (d) Klabunde, K.
J.; Stark, J.; Koper, O.; Mohs, C.; Park, D. G.; Decker, S.; Jiang, Y.;
Lagadic, I.; Zhang, D. Nanocrystals as stoichiometric reagents with unique
surface chemistry. J. Phys. Chem. 1996, 100, 12142–12153; (e) Choudary,
B. M.; Mulukutla, R. S.; Klabunde, K. J. Benzylation of aromatic com-
pounds with different crystallites of MgO. J. Am. Chem. Soc. 2003, 125,
2020–2021.