Photochirogenesis: multidimensional control of asymmetric photochemistry

Vital role of entropy in photochirogenesis

“…The origin of such dynamic behavior of product chirality and ee is exclusively entropic in nature. In the photoisomerization of 1Z with various chiral sensitizers, the stereochemistry of the photoproduct obtained at temperatures lower than T 0 is perfectly correlated with that of chiral substituent employed, and is anticipated from steric hindrance considerations [5]. Above T 0 , the entropic contribution surpasses the enthalpic factor, resulting in the inversion of product chirality.…”

“…Photochirogenesis, or photochemical generation of molecular chirality, is a relatively new area of chemistry that is rapidly growing, not only as a simple alternative to thermochemical or enzymatic asymmetric synthesis but also as a unique methodology for effecting asymmetric induction through the electronically excited state [1][2][3][4][5]. Photochemical asymmetric induction in the solution phase may be classified into three categories on the basis of the chiral source employed; the chiral interaction can take place between: 1) chiral light and molecule, 2) chiral molecule and molecule, and 3) chiral field and molecule.…”

Spin effects in intramolecular electron transfer in naproxen-N-methylpyrrolidine dyad

“…At present, there are only a few examples of the influence of chirality on photochemical processes [4,5,6,7,8,9,10,11,12]. The difference in the radical transformation of the (R) and (S) enantiomers of 2-phenylpropionic acid in the reaction with 4-methyl-2-quinolinecarbonitrile was detected using spin chemistry methods [13].…”

Spin Chemistry Investigation of Peculiarities of Photoinduced Electron Transfer in Donor–Acceptor Linked System

“…PET processes are investigated by various techniques including laser flash photolysis, Raman spectroscopy, pulse EPR spectroscopy and spin chemistry [7][8][9]. It is worth noting that in these studies the methods of spin chemistry occupy a special place.…”

“…Other possibilities like hydrogen transfer or energy transfer can be excluded. The electron transfer rate constants for (S,S)-and (R,S)-NPX-Pyr have been determined in [15] from the ratio of quantum yield and fluorescence lifetime to be k e =1.8×10 8 …”