ISSN 0965-5441, Petroleum Chemistry, 2006, Vol. 46, No. 1, pp. 25–27. © MAIK “Nauka /Interperiodica” (Russia), 2006.
Original Russian Text © G.F. Miralamov, Ch.I. Mamedov, 2006, published in Neftekhimiya, 2006, Vol. 46, No. 1, pp. 28–30.
Catalytic Epoxidation of Olefins
in the Presence of a Vanadyl Porphyrin Complex
1
G. F. Miralamov and Ch. I. Mamedov
OAO Azerbaijani Gas Processing Plant, Baku, Azerbaijan
1
e-mail: ggafar@mail.ru
Received August 31, 2005
Abstract—It was found that vanadyl porphyrin complexes synthesized from petroleum metal porphyrin con-
centrates stimulated epoxidation during the olefin oxygenation process. The yields of obtained oxiranes turned
out to be 38–75%, depending on the olefin structure. An epoxidation mechanism that suggests the formation of
a protonated dioxygen adduct as an intermediate during oxygenation of olefins in the presence of vanadyl por-
phyrin complexes was proposed. An analogy is drawn between the epoxide formation reaction upon the cata-
lytic oxygenation of olefins and the Prilezhaev reaction.
DOI: 10.1134/S0965544106010051
Catalytic epoxidation of olefins, apart from ethyl- on a TND T.S. inert support. The dimensions of the
ene, does not yield a desired oxirane under the severe U-tube column were 3 m × 3.5 mm.
conditions of heterogeneous catalysis. The Prilezhaev
Infrared spectra were measured on a UR-20 spec-
epoxidation of higher olefins is only of preparative
trometer.
interest. The development of industrial-scale processes
for the preparation of oxiranes from higher olefins with
high yields undoubtedly requires the use of low-cost
homogeneous epoxidation catalysts that would a pro-
cess to be conducted under mild conditions [1].
Catalytic Oxygenation Procedure
Dimethylformamide (100 ml), an olefin (0.5 mol), a
vanadyl porphyrin complex (0.05 mol), and glacial acetic
In [2], it was first reported that petroleum metal por- acid (5 ml) were loaded into a 400-ml stainless steel auto-
phyrins catalyzed the epoxidation of olefins during clave designed for a pressure up to 250 atm. The autoclave
their oxygenation.
was mounted in a shaker and connected to an oxygen cyl-
inder through a control unit including a high-sensitivity
pressure gauge. The temperature was adjusted to a neces-
sary level at a constant oxygen supply (3 atm) to the auto-
clave. The end of the reaction was determined as the ces-
sation of oxygen consumption. After completion of the
reaction, the autoclave contents were neutralized with
alkali at room temperature and the solution was filtered
and distilled with a fractionating column in vacuum pro-
duced by a water-jet pump. The yields and physical
parameters of oxiranes prepared are presented in the table.
Vanadyl porphyrin complexes prepared on the basis
of petroleum metal porphyrin concentrates are inexpen-
sive and promising homogeneous catalysts for the
oxirane preparation process by low-temperature oxy-
genation [3]. The advantage of the proposed method of
catalytic oxygenation of olefins is that the method per-
mits the manufacture of oxiranes with high yields and
opens new frontiers to the use of this process in petro-
leum refining. In particular, the octane number of cas-
ing-head gasoline was significantly increased by selec-
tive catalytic oxygenation of hydrocarbons in the pres-
ence of metal porphyrin complexes [4].
The samples of oxiranes 1–12 presented in the table
were also prepared by epoxidation of the corresponding
olefins by the Prilezhaev reaction [2]. cis-2,3-Epoxycy-
clohexan-1-ol (IV) was prepared by epoxidation of
In this paper, we present the results of catalytic
epoxidation of aliphatic and alicyclic olefins.
2
-cyclohexen-1-ol according to a procedure described
in [3]. The reduction of cis-epoxyalcohol IV with lith-
ium aluminum hydride was performed according to the
procedure described in [4].
EXPERIMENTAL
The main portion of obtained oxiranes 1–9 was deter-
We determined the optimum conditions for calalytic
mined by potentiometric titration with a standard 0.05 M epoxidation of olefins. The optimum temperature for the
hydrogen chloride solution. A glass electrode and a stan- epoxide formation reaction upon catalytic oxygenation
dard calomel electrode were used in the titration. The of olefins in the presence of vanadyl porphyrin complex
oxiranes were identified using an LKhM-8MD gas chro- was found to be 60–70°ë. The yields of oxiranes sharply
matograph. The stationary liquid phase was PEG-1000 decrease below this optimum temperature range. When
2
5