Highly Stereoselective Photocyclodimerization of α-Cyclodextrin-Appended Anthracene Mediated by γ-Cyclodextrin and Cucurbit[8]uril: A Dramatic Steric Effect Operating Outside the Binding Site

Photocyclodimerization of α-cyclodextrin (CD)-appended anthracene was studied in the presence of γ-CD and cucurbit[8]uril (CB[8]) hosts to manipulate the stereodifferentiating photoreaction occurring inside the cavity by the bulky attachment located outside. The γ-CD-mediated photodimerization affor...

Full description

Saved in:
Bibliographic Details
Published in:Journal of the American Chemical Society 2008-07, Vol.130 (27), p.8574-8575
Main Authors: Yang, Cheng, Mori, Tadashi, Origane, Yumi, Ko, Young Ho, Selvapalam, Narayanan, Kim, Kimoon, Inoue, Yoshihisa
Format: Article
Language:English
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Photocyclodimerization of α-cyclodextrin (CD)-appended anthracene was studied in the presence of γ-CD and cucurbit[8]uril (CB[8]) hosts to manipulate the stereodifferentiating photoreaction occurring inside the cavity by the bulky attachment located outside. The γ-CD-mediated photodimerization afforded the head-to-tail photodimers in 98% combined yield, in particular, the syn-head-to-tail photodimer of 91% ee in 68% yield, which are much greater than 32% ee and 44% yield obtained with unmodified anthracene carboxylate. The use of CB[8] also led to a striking inversion of the head-to-tail/head-to-head selectivity, affording exclusively the head-to-head photodimers in 99% combined yield.
ISSN:0002-7863
1520-5126
DOI:10.1021/ja8032923