Inorganica Chimica Acta
Research paper
Cyanosilylation of aldehydes catalyzed by mixed ligand copper(II)
complexes
Atash V. Gurbanov a,b, Ghodrat Mahmoudi , M. Fátima C. Guedes da Silva , Fedor I. Zubkov ,
Kamran T. Mahmudov
a
c
a
d
a,b,
⇑
a,
⇑
, Armando J.L. Pombeiro
Centro de Química Estrutural, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049–001 Lisbon, Portugal
Department of Chemistry, Baku State University, Z. Xalilov Str. 23, Az 1148 Baku, Azerbaijan
Department of Chemistry, Faculty of Science, University of Maragheh, P.O. Box 55181-83111, Maragheh, Iran
Organic Chemistry Department, RUDN University, 6 Miklukho-Maklaya str., Moscow 117198, Russian Federation
b
c
d
a r t i c l e i n f o
a b s t r a c t
Article history:
The new mixed ligand copper(II) complexes [Cu(HL)(H O)(A)]Á2H O (1, NaH L = sodium (Z)-2-(2-(1,3-
2
2
2
Received 21 September 2017
Received in revised form 29 October 2017
Accepted 31 October 2017
dioxo-1-(phenylamino)butan-2-ylidene)hydrazinyl)benzenesulfonate, A = dimethylsulfoxide, [Cu(HL)
(H
2
O)(B)] (2, B = 1,3,4-thiadiazol-2-amine), [Cu(HL)(H
2
O)(Y)]Á1/2CH
3
OH (3, C = hexamethylenetetramine)
and [Cu(HR) (H O) ](H L) (4, HR = methyl picolinimidate derived from 2-cyanopyridine) were synthe-
2
2
2
2
2
sized and characterized by IR and ESI-MS spectroscopies, elemental and X-ray crystal structural analyses.
These compounds act as homogenous catalysts for the cyanosilylation reaction of a variety of both aro-
matic and aliphatic aldehydes with trimethylsilyl cyanide affording the corresponding cyanohydrin
trimethylsilyl ethers in high yields (up to 85–99 %) in methanol and at room temperature.
Ó 2017 Elsevier B.V. All rights reserved.
Keywords:
Arylhydrazones of acetoacetanilide
Mixed ligand Cu complexes
Cyanosilylation reaction of aldehydes with
trimethylsilyl cyanide
II
1
. Introduction
Catalytic hydrocyanation and cyanosilylation of aldehydes or
harmful solvents, etc. Therefore, the development of a new
homogeneous catalytic system, which is inexpensive, commonly
available, easy to handle and time resolved, is highly desirable.
On the other hand, the design and synthesis of mixed ligand
complexes have received considerable attention due to their struc-
tural diversity as well as their potential applications as functional
materials in various fields such as catalysis, pharmacology, molec-
ular recognition, molecular switches, etc. [41–44]. Up to now, a
great number of mixed ligand copper(II) complexes with interest-
ing structures and properties have been obtained by selecting the
appropriate hydrazone (main) and auxiliary ligands [45]. However,
the controllable synthesis of mixed ligand copper(II) complexes
with desired catalytic properties is still a great challenge because
there are many chemical and physical factors playing important
roles in the synthetic operation, such as the molecular structures
of the main ligands, acid-base properties of auxiliary ligands,
reaction condition, etc.
ketones are among the most important strategies for synthesis of
cyanohydrin trimethylsilyl ethers in synthetic chemistry
(
Scheme 1) [1]. The cyanohydrin trimethylsilyl ethers are industri-
ally valuable and important intermediates for the synthesis of
many valuable molecules such as -hydroxy aldehydes, -hydroxy
a
a
acids and b-amino alcohols and other biologically active
compounds [1]. Hence, a number of catalysts such as Lewis acids
[
2–4], Lewis bases [5–7], N-heterocyclic carbenes [8,9], amino-
thiourea [10,11], organic–inorganic salts [12–16], nonionic bases
17,18], oxazaborolidinium ion [19,20], V-, Mn-, Al-, and Ti-salen
complexes [21–24], chiral Ti- -1,3-dioxolane-tetraaryl-4,5-
[
a,a,a,a
dimethanols [25,26], Ti,Al-phosphine oxide bifunctional catalysts
with carbohydrate or binaphthol scaffolds [27–29], Ti,Al-N-oxide
bifunctional catalysts with proline, pyrrolidine and 1,2-diamino
ligands [30–32], metal organic frameworks [33–36], Cu(II) and Co
Therefore, the two main objectives of the current work are as
follows: i) to synthesize of mixed ligand copper(II) complexes by
using known sodium (Z)-2-(2-(1,3-dioxo-1-(phenylamino)butan-
(
II/III) hydrazone complexes [37–40], etc. have been utilized. Based
on the existing methods, it is clear that most of these protocols
have many disadvantages, such as low yield, long reaction time,
2
2-ylidene)hydrazinyl)benzenesulfonate (NaH L) [46] and axulliary
components such as dimethylsulfoxide, 1,3,4-thiadiazol-2-amine,
hexamethylenetetramine and 2-cyanopyridine; ii) to apply the
derived mixed ligand copper(II) complexes as the homogeneous
⇑
Corresponding authors.
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020-1693/Ó 2017 Elsevier B.V. All rights reserved.
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