Abstract
Photochemistry of 17 aryl alkyl ketones included within cation exchanged zeolites has been examined. In solution five of the 17 ketones undergo intramolecular hydrogen abstraction reaction even in the presence of a chiral amine and the rest are photoreduced to the corresponding alcohol. Within zeolites all 17 ketones yielded in presence of a chiral amine, the corresponding alcohol as the major product. When a chiral amine was used as the coadsorbent within alkali ion exchanged zeolites, enantiomerically enriched alcohol was formed in all cases. The best chiral induction was obtained with phenyl cyclohexyl ketone (enantiomeric excess: 68%). 1H-13C Cross Polarization Magic Angle Spinning (CP-MAS) experiments, with a model ketone (perdeuterated acetophenone) and chiral amine (pseudoephedrine) included within MY zeolites, suggested that the cation brings the reactant and the chiral amine closer. The role of the cation in such a process is also revealed by the computation results. The results presented here highlight the importance of a supramolecular structure in forcing a closer interaction between a reactant and a chiral inductor that could be used to achieve asymmetric induction in photoproducts.
| Original language | English |
|---|---|
| Pages (from-to) | 1561-1571 |
| Number of pages | 11 |
| Journal | Organic and Biomolecular Chemistry |
| Volume | 4 |
| Issue number | 8 |
| DOIs | |
| State | Published - Jun 5 2006 |
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ASJC Scopus subject areas
- Biochemistry, Genetics and Molecular Biology(all)
- Chemistry(all)
Cite this
Asymmetric induction during electron transfer mediated photoreduction of carbonyl compounds : Role of zeolites. / Shailaja, J.; Kaanumalle, Lakshmi S.; Sivasubramanian, Karthikeyan; Natarajan, Arunkumar; Ponchot, Keith J.; Pradhan, Ajit; Ramamurthy, Vaidhyanathan.
In: Organic and Biomolecular Chemistry, Vol. 4, No. 8, 05.06.2006, p. 1561-1571.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Asymmetric induction during electron transfer mediated photoreduction of carbonyl compounds
T2 - Role of zeolites
AU - Shailaja, J.
AU - Kaanumalle, Lakshmi S.
AU - Sivasubramanian, Karthikeyan
AU - Natarajan, Arunkumar
AU - Ponchot, Keith J.
AU - Pradhan, Ajit
AU - Ramamurthy, Vaidhyanathan
PY - 2006/6/5
Y1 - 2006/6/5
N2 - Photochemistry of 17 aryl alkyl ketones included within cation exchanged zeolites has been examined. In solution five of the 17 ketones undergo intramolecular hydrogen abstraction reaction even in the presence of a chiral amine and the rest are photoreduced to the corresponding alcohol. Within zeolites all 17 ketones yielded in presence of a chiral amine, the corresponding alcohol as the major product. When a chiral amine was used as the coadsorbent within alkali ion exchanged zeolites, enantiomerically enriched alcohol was formed in all cases. The best chiral induction was obtained with phenyl cyclohexyl ketone (enantiomeric excess: 68%). 1H-13C Cross Polarization Magic Angle Spinning (CP-MAS) experiments, with a model ketone (perdeuterated acetophenone) and chiral amine (pseudoephedrine) included within MY zeolites, suggested that the cation brings the reactant and the chiral amine closer. The role of the cation in such a process is also revealed by the computation results. The results presented here highlight the importance of a supramolecular structure in forcing a closer interaction between a reactant and a chiral inductor that could be used to achieve asymmetric induction in photoproducts.
AB - Photochemistry of 17 aryl alkyl ketones included within cation exchanged zeolites has been examined. In solution five of the 17 ketones undergo intramolecular hydrogen abstraction reaction even in the presence of a chiral amine and the rest are photoreduced to the corresponding alcohol. Within zeolites all 17 ketones yielded in presence of a chiral amine, the corresponding alcohol as the major product. When a chiral amine was used as the coadsorbent within alkali ion exchanged zeolites, enantiomerically enriched alcohol was formed in all cases. The best chiral induction was obtained with phenyl cyclohexyl ketone (enantiomeric excess: 68%). 1H-13C Cross Polarization Magic Angle Spinning (CP-MAS) experiments, with a model ketone (perdeuterated acetophenone) and chiral amine (pseudoephedrine) included within MY zeolites, suggested that the cation brings the reactant and the chiral amine closer. The role of the cation in such a process is also revealed by the computation results. The results presented here highlight the importance of a supramolecular structure in forcing a closer interaction between a reactant and a chiral inductor that could be used to achieve asymmetric induction in photoproducts.
UR - http://www.scopus.com/inward/record.url?scp=33744484283&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=33744484283&partnerID=8YFLogxK
U2 - 10.1039/b517069a
DO - 10.1039/b517069a
M3 - Article
C2 - 16604225
AN - SCOPUS:33744484283
VL - 4
SP - 1561
EP - 1571
JO - Organic and Biomolecular Chemistry
JF - Organic and Biomolecular Chemistry
SN - 1477-0520
IS - 8
ER -