Mammalian serum albumins as a chiral mediator library for bio-supramolecular photochirogenesis: optimizing enantiodifferentiating photocyclodimerization of 2-anthracenecarboxylate.

A simple strategy for choosing optimal bio-supramolecular mediators from the mammalian serum albumin library is proposed for bimolecular photochirogenic reactions. Thus, the enantiodifferentiating photocyclodimerization of 2-anthracencecarboxylate (AC) was optimized in chemical and optical yields, when mediated by porcine and canine serum albumins, both of which bound two AC molecules in the first productive site to give the (P)-enantiomer of syn-head-to-tail-cyclodimer in 69% yield and 89% enantiomeric excess (ee) for the former but the (M)-enantiomer in 77% yield and 97% ee for the latter.