Absolute Asymmetric Photocyclization of a Photochromic Diarylethene Derivative in Single Crystals

摘要

In recent years there has been considerable scientific interest in the photochemistry of compounds in crystals.~[1] The topics range widely from chemiluminescence in silicon nanocrystals~[2] to chemical reactivity in crystals.~[3] One unique aspect of crystal-phase reactionse is topochemical reactivity. The crystal lattice provides a matrix for reactions with stereo-, regio-, and enantiospectificity. Enantiospecific reactions can take place in chiral crystal containing chiral auxiliaries such as chiral host molecules~[4] and covalently bonded chiral substituents.~[5] Moreover, an ensemble of achiral molecules can be transformed by reactions into chiral molecules on crystallization in a chiral space group. Such an asymmetric reaction in the absence of any outside chiral influence is referred to as absolute asymmetric synthesis.