INVESTIGADORES
BONESI Sergio Mauricio
artículos
Título:
Photosensitized eletron transfer oxidation of sulfides: A steady-state study
Autor/es:
SERGIO M. BONESI, MAURIZIO FAGNONI, ANGELO ALBINI
Revista:
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
Editorial:
Wiley-VCH Verlag GmbH and Co
Referencias:
Lugar: Weinheim; Año: 2008 p. 2612 - 2620
ISSN:
1434-193X
Resumen:
The photosensitized electron-transfer oxidation of a series of
ethyl sulfides RSEt (1, R = C12H25; 2, PhCH2CH2; 3, PhCH2;1, R = C12H25; 2, PhCH2CH2; 3, PhCH2;
4, PhCMe2; 5, Ph2CH) has been examined in acetonitrile and
the product distribution discussed on the basis of the mechanisms
proposed. In nitrogen-flushed solutions, cleaved
alcohols and alkenes are formed, whereas under oxygen, in
reactions that are 1070 times faster, sulfoxides and cleaved
aldehydes and ketones are formed in addition to the aforementioned
products. Two sensitizers are compared, 9,10-dicyanoanthracene
(DCA) and 2,4,6-triphenylpyrylium tetrafluoroborate
(TPP+BF4
), the former giving a higher proportion
of the sulfoxide, the latter of cleaved carbonyls. The
sulfoxidation is due to the contribution of the singlet oxygen
path with DCA. Oxidative cleavage, on the other hand, occurs
both with DCA and with TPP+ which is known to produce
neither singlet oxygen nor the superoxide anion. This
process involves deprotonation from the á position of the sulfide
radical cation, but the TPP+ results suggest that O2
radical cation, but the TPP+ results suggest that O2
neither singlet oxygen nor the superoxide anion. This
process involves deprotonation from the á position of the sulfide
radical cation, but the TPP+ results suggest that O2
radical cation, but the TPP+ results suggest that O2
sulfoxidation is due to the contribution of the singlet oxygen
path with DCA. Oxidative cleavage, on the other hand, occurs
both with DCA and with TPP+ which is known to produce
neither singlet oxygen nor the superoxide anion. This
process involves deprotonation from the á position of the sulfide
radical cation, but the TPP+ results suggest that O2
radical cation, but the TPP+ results suggest that O2
neither singlet oxygen nor the superoxide anion. This
process involves deprotonation from the á position of the sulfide
radical cation, but the TPP+ results suggest that O2
radical cation, but the TPP+ results suggest that O2
sulfoxidation is due to the contribution of the singlet oxygen
path with DCA. Oxidative cleavage, on the other hand, occurs
both with DCA and with TPP+ which is known to produce
neither singlet oxygen nor the superoxide anion. This
process involves deprotonation from the á position of the sulfide
radical cation, but the TPP+ results suggest that O2
radical cation, but the TPP+ results suggest that O2
neither singlet oxygen nor the superoxide anion. This
process involves deprotonation from the á position of the sulfide
radical cation, but the TPP+ results suggest that O2
radical cation, but the TPP+ results suggest that O2
neither singlet oxygen nor the superoxide anion. This
process involves deprotonation from the á position of the sulfide
radical cation, but the TPP+ results suggest that O2
radical cation, but the TPP+ results suggest that O2
radical cation, but the TPP+ results suggest that O2
· is
not necessarily involved and non-activated oxygen forms a
weak adduct with the radical cation promoting á-hydrogen
transfer, particularly with benzylic derivatives.
(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim,
Germany, 2008)
transfer, particularly with benzylic derivatives.
(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim,
Germany, 2008)
not necessarily involved and non-activated oxygen forms a
weak adduct with the radical cation promoting á-hydrogen
transfer, particularly with benzylic derivatives.
(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim,
Germany, 2008)
transfer, particularly with benzylic derivatives.
(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim,
Germany, 2008)
is
not necessarily involved and non-activated oxygen forms a
weak adduct with the radical cation promoting á-hydrogen
transfer, particularly with benzylic derivatives.
(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim,
Germany, 2008)
transfer, particularly with benzylic derivatives.
(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim,
Germany, 2008)
á-hydrogen
transfer, particularly with benzylic derivatives.
(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim,
Germany, 2008)
of the sulfoxide, the latter of cleaved carbonyls. The
sulfoxidation is due to the contribution of the singlet oxygen
path with DCA. Oxidative cleavage, on the other hand, occurs
both with DCA and with TPP+ which is known to produce
neither singlet oxygen nor the superoxide anion. This
process involves deprotonation from the á position of the sulfide
radical cation, but the TPP+ results suggest that O2
radical cation, but the TPP+ results suggest that O2
neither singlet oxygen nor the superoxide anion. This
process involves deprotonation from the á position of the sulfide
radical cation, but the TPP+ results suggest that O2
radical cation, but the TPP+ results suggest that O2
sulfoxidation is due to the contribution of the singlet oxygen
path with DCA. Oxidative cleavage, on the other hand, occurs
both with DCA and with TPP+ which is known to produce
neither singlet oxygen nor the superoxide anion. This
process involves deprotonation from the á position of the sulfide
radical cation, but the TPP+ results suggest that O2
radical cation, but the TPP+ results suggest that O2
neither singlet oxygen nor the superoxide anion. This
process involves deprotonation from the á position of the sulfide
radical cation, but the TPP+ results suggest that O2
radical cation, but the TPP+ results suggest that O2
sulfoxidation is due to the contribution of the singlet oxygen
path with DCA. Oxidative cleavage, on the other hand, occurs
both with DCA and with TPP+ which is known to produce
neither singlet oxygen nor the superoxide anion. This
process involves deprotonation from the á position of the sulfide
radical cation, but the TPP+ results suggest that O2
radical cation, but the TPP+ results suggest that O2
neither singlet oxygen nor the superoxide anion. This
process involves deprotonation from the á position of the sulfide
radical cation, but the TPP+ results suggest that O2
radical cation, but the TPP+ results suggest that O2
neither singlet oxygen nor the superoxide anion. This
process involves deprotonation from the á position of the sulfide
radical cation, but the TPP+ results suggest that O2
radical cation, but the TPP+ results suggest that O2
radical cation, but the TPP+ results suggest that O2
· is
not necessarily involved and non-activated oxygen forms a
weak adduct with the radical cation promoting á-hydrogen
transfer, particularly with benzylic derivatives.
(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim,
Germany, 2008)
transfer, particularly with benzylic derivatives.
(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim,
Germany, 2008)
not necessarily involved and non-activated oxygen forms a
weak adduct with the radical cation promoting á-hydrogen
transfer, particularly with benzylic derivatives.
(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim,
Germany, 2008)
transfer, particularly with benzylic derivatives.
(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim,
Germany, 2008)
is
not necessarily involved and non-activated oxygen forms a
weak adduct with the radical cation promoting á-hydrogen
transfer, particularly with benzylic derivatives.
(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim,
Germany, 2008)
transfer, particularly with benzylic derivatives.
(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim,
Germany, 2008)
á-hydrogen
transfer, particularly with benzylic derivatives.
(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim,
Germany, 2008)
), the former giving a higher proportion
of the sulfoxide, the latter of cleaved carbonyls. The
sulfoxidation is due to the contribution of the singlet oxygen
path with DCA. Oxidative cleavage, on the other hand, occurs
both with DCA and with TPP+ which is known to produce
neither singlet oxygen nor the superoxide anion. This
process involves deprotonation from the á position of the sulfide
radical cation, but the TPP+ results suggest that O2
radical cation, but the TPP+ results suggest that O2
neither singlet oxygen nor the superoxide anion. This
process involves deprotonation from the á position of the sulfide
radical cation, but the TPP+ results suggest that O2
radical cation, but the TPP+ results suggest that O2
sulfoxidation is due to the contribution of the singlet oxygen
path with DCA. Oxidative cleavage, on the other hand, occurs
both with DCA and with TPP+ which is known to produce
neither singlet oxygen nor the superoxide anion. This
process involves deprotonation from the á position of the sulfide
radical cation, but the TPP+ results suggest that O2
radical cation, but the TPP+ results suggest that O2
neither singlet oxygen nor the superoxide anion. This
process involves deprotonation from the á position of the sulfide
radical cation, but the TPP+ results suggest that O2
radical cation, but the TPP+ results suggest that O2
sulfoxidation is due to the contribution of the singlet oxygen
path with DCA. Oxidative cleavage, on the other hand, occurs
both with DCA and with TPP+ which is known to produce
neither singlet oxygen nor the superoxide anion. This
process involves deprotonation from the á position of the sulfide
radical cation, but the TPP+ results suggest that O2
radical cation, but the TPP+ results suggest that O2
neither singlet oxygen nor the superoxide anion. This
process involves deprotonation from the á position of the sulfide
radical cation, but the TPP+ results suggest that O2
radical cation, but the TPP+ results suggest that O2
neither singlet oxygen nor the superoxide anion. This
process involves deprotonation from the á position of the sulfide
radical cation, but the TPP+ results suggest that O2
radical cation, but the TPP+ results suggest that O2
radical cation, but the TPP+ results suggest that O2
· is
not necessarily involved and non-activated oxygen forms a
weak adduct with the radical cation promoting á-hydrogen
transfer, particularly with benzylic derivatives.
(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim,
Germany, 2008)
transfer, particularly with benzylic derivatives.
(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim,
Germany, 2008)
not necessarily involved and non-activated oxygen forms a
weak adduct with the radical cation promoting á-hydrogen
transfer, particularly with benzylic derivatives.
(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim,
Germany, 2008)
transfer, particularly with benzylic derivatives.
(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim,
Germany, 2008)
is
not necessarily involved and non-activated oxygen forms a
weak adduct with the radical cation promoting á-hydrogen
transfer, particularly with benzylic derivatives.
(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim,
Germany, 2008)
transfer, particularly with benzylic derivatives.
(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim,
Germany, 2008)
á-hydrogen
transfer, particularly with benzylic derivatives.
(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim,
Germany, 2008)
of the sulfoxide, the latter of cleaved carbonyls. The
sulfoxidation is due to the contribution of the singlet oxygen
path with DCA. Oxidative cleavage, on the other hand, occurs
both with DCA and with TPP+ which is known to produce
neither singlet oxygen nor the superoxide anion. This
process involves deprotonation from the á position of the sulfide
radical cation, but the TPP+ results suggest that O2
radical cation, but the TPP+ results suggest that O2
neither singlet oxygen nor the superoxide anion. This
process involves deprotonation from the á position of the sulfide
radical cation, but the TPP+ results suggest that O2
radical cation, but the TPP+ results suggest that O2
sulfoxidation is due to the contribution of the singlet oxygen
path with DCA. Oxidative cleavage, on the other hand, occurs
both with DCA and with TPP+ which is known to produce
neither singlet oxygen nor the superoxide anion. This
process involves deprotonation from the á position of the sulfide
radical cation, but the TPP+ results suggest that O2
radical cation, but the TPP+ results suggest that O2
neither singlet oxygen nor the superoxide anion. This
process involves deprotonation from the á position of the sulfide
radical cation, but the TPP+ results suggest that O2
radical cation, but the TPP+ results suggest that O2
sulfoxidation is due to the contribution of the singlet oxygen
path with DCA. Oxidative cleavage, on the other hand, occurs
both with DCA and with TPP+ which is known to produce
neither singlet oxygen nor the superoxide anion. This
process involves deprotonation from the á position of the sulfide
radical cation, but the TPP+ results suggest that O2
radical cation, but the TPP+ results suggest that O2
neither singlet oxygen nor the superoxide anion. This
process involves deprotonation from the á position of the sulfide
radical cation, but the TPP+ results suggest that O2
radical cation, but the TPP+ results suggest that O2
neither singlet oxygen nor the superoxide anion. This
process involves deprotonation from the á position of the sulfide
radical cation, but the TPP+ results suggest that O2
radical cation, but the TPP+ results suggest that O2
radical cation, but the TPP+ results suggest that O2
· is
not necessarily involved and non-activated oxygen forms a
weak adduct with the radical cation promoting á-hydrogen
transfer, particularly with benzylic derivatives.
(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim,
Germany, 2008)
transfer, particularly with benzylic derivatives.
(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim,
Germany, 2008)
not necessarily involved and non-activated oxygen forms a
weak adduct with the radical cation promoting á-hydrogen
transfer, particularly with benzylic derivatives.
(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim,
Germany, 2008)
transfer, particularly with benzylic derivatives.
(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim,
Germany, 2008)
is
not necessarily involved and non-activated oxygen forms a
weak adduct with the radical cation promoting á-hydrogen
transfer, particularly with benzylic derivatives.
(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim,
Germany, 2008)
transfer, particularly with benzylic derivatives.
(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim,
Germany, 2008)
á-hydrogen
transfer, particularly with benzylic derivatives.
(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim,
Germany, 2008)
the product distribution discussed on the basis of the mechanisms
proposed. In nitrogen-flushed solutions, cleaved
alcohols and alkenes are formed, whereas under oxygen, in
reactions that are 1070 times faster, sulfoxides and cleaved
aldehydes and ketones are formed in addition to the aforementioned
products. Two sensitizers are compared, 9,10-dicyanoanthracene
(DCA) and 2,4,6-triphenylpyrylium tetrafluoroborate
(TPP+BF4
), the former giving a higher proportion
of the sulfoxide, the latter of cleaved carbonyls. The
sulfoxidation is due to the contribution of the singlet oxygen
path with DCA. Oxidative cleavage, on the other hand, occurs
both with DCA and with TPP+ which is known to produce
neither singlet oxygen nor the superoxide anion. This
process involves deprotonation from the á position of the sulfide
radical cation, but the TPP+ results suggest that O2
radical cation, but the TPP+ results suggest that O2
neither singlet oxygen nor the superoxide anion. This
process involves deprotonation from the á position of the sulfide
radical cation, but the TPP+ results suggest that O2
radical cation, but the TPP+ results suggest that O2
sulfoxidation is due to the contribution of the singlet oxygen
path with DCA. Oxidative cleavage, on the other hand, occurs
both with DCA and with TPP+ which is known to produce
neither singlet oxygen nor the superoxide anion. This
process involves deprotonation from the á position of the sulfide
radical cation, but the TPP+ results suggest that O2
radical cation, but the TPP+ results suggest that O2
neither singlet oxygen nor the superoxide anion. This
process involves deprotonation from the á position of the sulfide
radical cation, but the TPP+ results suggest that O2
radical cation, but the TPP+ results suggest that O2
sulfoxidation is due to the contribution of the singlet oxygen
path with DCA. Oxidative cleavage, on the other hand, occurs
both with DCA and with TPP+ which is known to produce
neither singlet oxygen nor the superoxide anion. This
process involves deprotonation from the á position of the sulfide
radical cation, but the TPP+ results suggest that O2
radical cation, but the TPP+ results suggest that O2
neither singlet oxygen nor the superoxide anion. This
process involves deprotonation from the á position of the sulfide
radical cation, but the TPP+ results suggest that O2
radical cation, but the TPP+ results suggest that O2
neither singlet oxygen nor the superoxide anion. This
process involves deprotonation from the á position of the sulfide
radical cation, but the TPP+ results suggest that O2
radical cation, but the TPP+ results suggest that O2
radical cation, but the TPP+ results suggest that O2
· is
not necessarily involved and non-activated oxygen forms a
weak adduct with the radical cation promoting á-hydrogen
transfer, particularly with benzylic derivatives.
(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim,
Germany, 2008)
transfer, particularly with benzylic derivatives.
(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim,
Germany, 2008)
not necessarily involved and non-activated oxygen forms a
weak adduct with the radical cation promoting á-hydrogen
transfer, particularly with benzylic derivatives.
(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim,
Germany, 2008)
transfer, particularly with benzylic derivatives.
(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim,
Germany, 2008)
is
not necessarily involved and non-activated oxygen forms a
weak adduct with the radical cation promoting á-hydrogen
transfer, particularly with benzylic derivatives.
(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim,
Germany, 2008)
transfer, particularly with benzylic derivatives.
(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim,
Germany, 2008)
á-hydrogen
transfer, particularly with benzylic derivatives.
(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim,
Germany, 2008)
of the sulfoxide, the latter of cleaved carbonyls. The
sulfoxidation is due to the contribution of the singlet oxygen
path with DCA. Oxidative cleavage, on the other hand, occurs
both with DCA and with TPP+ which is known to produce
neither singlet oxygen nor the superoxide anion. This
process involves deprotonation from the á position of the sulfide
radical cation, but the TPP+ results suggest that O2
radical cation, but the TPP+ results suggest that O2
neither singlet oxygen nor the superoxide anion. This
process involves deprotonation from the á position of the sulfide
radical cation, but the TPP+ results suggest that O2
radical cation, but the TPP+ results suggest that O2
sulfoxidation is due to the contribution of the singlet oxygen
path with DCA. Oxidative cleavage, on the other hand, occurs
both with DCA and with TPP+ which is known to produce
neither singlet oxygen nor the superoxide anion. This
process involves deprotonation from the á position of the sulfide
radical cation, but the TPP+ results suggest that O2
radical cation, but the TPP+ results suggest that O2
neither singlet oxygen nor the superoxide anion. This
process involves deprotonation from the á position of the sulfide
radical cation, but the TPP+ results suggest that O2
radical cation, but the TPP+ results suggest that O2
sulfoxidation is due to the contribution of the singlet oxygen
path with DCA. Oxidative cleavage, on the other hand, occurs
both with DCA and with TPP+ which is known to produce
neither singlet oxygen nor the superoxide anion. This
process involves deprotonation from the á position of the sulfide
radical cation, but the TPP+ results suggest that O2
radical cation, but the TPP+ results suggest that O2
neither singlet oxygen nor the superoxide anion. This
process involves deprotonation from the á position of the sulfide
radical cation, but the TPP+ results suggest that O2
radical cation, but the TPP+ results suggest that O2
neither singlet oxygen nor the superoxide anion. This
process involves deprotonation from the á position of the sulfide
radical cation, but the TPP+ results suggest that O2
radical cation, but the TPP+ results suggest that O2
radical cation, but the TPP+ results suggest that O2
· is
not necessarily involved and non-activated oxygen forms a
weak adduct with the radical cation promoting á-hydrogen
transfer, particularly with benzylic derivatives.
(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim,
Germany, 2008)
transfer, particularly with benzylic derivatives.
(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim,
Germany, 2008)
not necessarily involved and non-activated oxygen forms a
weak adduct with the radical cation promoting á-hydrogen
transfer, particularly with benzylic derivatives.
(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim,
Germany, 2008)
transfer, particularly with benzylic derivatives.
(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim,
Germany, 2008)
is
not necessarily involved and non-activated oxygen forms a
weak adduct with the radical cation promoting á-hydrogen
transfer, particularly with benzylic derivatives.
(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim,
Germany, 2008)
transfer, particularly with benzylic derivatives.
(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim,
Germany, 2008)
á-hydrogen
transfer, particularly with benzylic derivatives.
(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim,
Germany, 2008)
), the former giving a higher proportion
of the sulfoxide, the latter of cleaved carbonyls. The
sulfoxidation is due to the contribution of the singlet oxygen
path with DCA. Oxidative cleavage, on the other hand, occurs
both with DCA and with TPP+ which is known to produce
neither singlet oxygen nor the superoxide anion. This
process involves deprotonation from the á position of the sulfide
radical cation, but the TPP+ results suggest that O2
radical cation, but the TPP+ results suggest that O2
neither singlet oxygen nor the superoxide anion. This
process involves deprotonation from the á position of the sulfide
radical cation, but the TPP+ results suggest that O2
radical cation, but the TPP+ results suggest that O2
sulfoxidation is due to the contribution of the singlet oxygen
path with DCA. Oxidative cleavage, on the other hand, occurs
both with DCA and with TPP+ which is known to produce
neither singlet oxygen nor the superoxide anion. This
process involves deprotonation from the á position of the sulfide
radical cation, but the TPP+ results suggest that O