PMID- 12537495
OWN - NLM
STAT- PubMed-not-MEDLINE
DCOM- 20030409
LR  - 20031104
IS  - 0002-7863 (Print)
IS  - 0002-7863 (Linking)
VI  - 125
IP  - 4
DP  - 2003 Jan 29
TI  - Supramolecular catalysis of the enantiodifferentiating [4 + 4] 
      photocyclodimerization of 2-anthracenecarboxylate by gamma-cyclodextrin.
PG  - 966-72
AB  - 2-Anthracenecarboxylic acid (AC) makes a very stable 1:2 inclusion complex with 
      gamma-cyclodextrin (gamma-CDx) (K(1) = 161 +/- 25 M(-1), K(2) = 38 500 +/- 3300 
      M(-1) at 25 degrees C). The formation of the 1:2 inclusion complex accelerated 
      the photocyclodimerization of AC. The 1:2 inclusion could be clearly verified by 
      UV-vis, CD, and (1)H NMR spectroscopies. Although these spectroscopies provide 
      little information about the structural isomers of the inclusion complex, there 
      should be several structural isomers of the 1:2 inclusion complex which have a 
      different longitudinal orientation of the guest molecules in the cavity. The 
      isomer distribution of the photodimerization product primarily depends on the 
      population of these orientational isomers of the 1:2 inclusion complex in the 
      ground state before photoreaction, because, in the lifetime of the excited 
      singlet state, exchanging the orientation is impossible. The enantioselectivity 
      of the photodimerization originates from the difference in the stability of the 
      diastereomeric pair of orientational isomers of the 1:2 inclusion complex in the 
      ground state, which are the precursors of the enantiomers of a specific chiral 
      cyclodimer. The ee of a chiral cyclodimer 2 was 32% at 25 degrees C and was 
      enhanced by lowering the temperature to 41% at 0 degrees C. This is the highest 
      value reported for the asymmetric photodimerization in solution.
FAU - Nakamura, Asao
AU  - Nakamura A
AD  - Inoue Photochirogenesis Project (ERATO) and Entropy Control Project (ICORP), JST, 
      4-6-3 Kamishinden, Toyonaka 560-0085, Japan. asao@chiromor.jst.go.jp
FAU - Inoue, Yoshihisa
AU  - Inoue Y
LA  - eng
PT  - Journal Article
PL  - United States
TA  - J Am Chem Soc
JT  - Journal of the American Chemical Society
JID - 7503056
EDAT- 2003/01/23 04:00
MHDA- 2003/01/23 04:01
CRDT- 2003/01/23 04:00
PHST- 2003/01/23 04:00 [pubmed]
PHST- 2003/01/23 04:01 [medline]
PHST- 2003/01/23 04:00 [entrez]
AID - 10.1021/ja016238k [doi]
PST - ppublish
SO  - J Am Chem Soc. 2003 Jan 29;125(4):966-72. doi: 10.1021/ja016238k.