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Synfacts 2011(4): 0388-0388  
DOI: 10.1055/s-0030-1259633
Synthesis of Materials and Unnatural Products
© Georg Thieme Verlag Stuttgart ˙ New York

Photon-Quantitative Cyclization of Dithiazolylarylene

Contributor(s): Timothy M. Swager, Jan M. Schnorr
S. Fukumoto, T. Nakashima, T. Kawai*
Nara Institute of Science and Technology, Ikoma, Japan
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Publication History

Publication Date:
18 March 2011 (online)

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Significance

The authors describe the synthesis of the photochromic dithiazolylbenzothiophene 3. Whereas weak intramolecular hydrogen-bonding interaction as well as S-N heteroatom-contact ­interaction favors the coplanarity of the heteroaromatic rings, the steric hindrance between the two methyl groups induces a twist in the molecule. As a result, the hexatriene moiety is C 2-symmetrical. This conformation facilitates the photocyclization to 4 resulting in a quantum yield for this process of almost 100%.