Recent progress on the enantioselective excited-state photoreactions by pre-arrangement of photosubstrate(s)

Abstract

The short lifetime and high reactivity of the molecular excited states were the main culprits for the low achieved enantioselectivity of the excited-state photoreactions. Supramolecular strategies by confining the prochiral substrates in a chiral microenvironment prior to photoexcitation were excellent solutions for the challenges mentioned above. In the present review, endeavors to enhance the enantioselectivities of the photoreactions by pre-arranging the conformations of the substrate(s) were summarized, and the photoreactions accelerated by substoichiometric amount of mediums were paid special attention from atom economy and green chemistry points of view. For the sake of brevity, we mainly focused on the advances of supramolecular chiral photochemistry in chiral pre-arrangements reported in the recent 5 years.

Keywords

• Excited-state photoreaction
• Asymmetric synthesis
• Supramolecular catalysis
• Macrocyclic hosts
• Chiral templates
• Hydrogen bonding templates