Enantiospecific 6π-photocyclization of atropisomeric α-substituted acrylanilides in the solid-state: role of crystalline confinement on enantiospecificity.
نویسندگان
چکیده
Direct irradiation of optically-pure axially-chiral α-substituted acrylanilides in the crystalline state leads to 3,4-dihydro-2-quinolin-2-one photoproduct with an enantiomeric ratio of 85 : 15 while a racemic mixture of photoproduct is observed in solution.
منابع مشابه
Reactive spin state dependent enantiospecific photocyclization of axially chiral α-substituted acrylanilides.
The enantiomeric ratio (e.r.) in the 3,4-dihydroquinolin-2-one photoproduct during 6π-photocyclization of α-substituted axially chiral ortho-tert-butyl-acrylanilides depends on the nature of the reactive spin state (singlet or triplet), where the singlet-spin state reactivity gives a racemic mixture and the triplet reactivity gives an e.r. value >95 : 5.
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Direct irradiation of atropisomeric α-substituted acrylanilides in the presence of alkali metal ions gave high ee values in the 3,4-dihydro-2-quinolin-2-one photoproduct, while in the absence of alkali metal ions, racemic photoproduct was observed. The heavy atom effect leading to enhanced triplet yields alters the reactive pathway leading to the observed enantioselectivity in the photoproduct.
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عنوان ژورنال:
- Photochemical & photobiological sciences : Official journal of the European Photochemistry Association and the European Society for Photobiology
دوره 10 9 شماره
صفحات -
تاریخ انتشار 2011