Rapid Photoracemization of Chiral Alkyl Aryl Sulfoxides.
J Org Chem
; 86(23): 17249-17256, 2021 Dec 03.
Article
em En
| MEDLINE
| ID: mdl-34806388
ABSTRACT
The photoracemization of chiral alkyl aryl sulfoxides with a photosensitizer has not been sufficiently investigated thus far. Therefore, in this study, a rapid photoracemization reaction of enantiopure alkyl aryl sulfoxides using 1 mol % 2,4,6-triphenylpyrylium tetrafluoroborate (TPT+) was developed. Various substitution patterns were tolerated and every racemization reaction proceeded extremely fast (k2 = 1.77 × 104-6.08 × 101 M-1 s-1, t1/2 = 0.4-114 s). Some chiral sulfoxides with easily oxidizable functional groups are not appropriate for this photoisomerization. The electrochemical potentials of the functional groups, determined via cyclic voltammetry, are useful for predicting the reactive or nonreactive groups in this photoracemization reaction. A theoretical study was conducted to clarify the sp2-like nature of S of the sulfoxide cation radical, which makes photoracemization easier.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Idioma:
En
Ano de publicação:
2021
Tipo de documento:
Article