Liang, Kangjiang published the artcileEnantioselective Radical Cyclization of Tryptamines by Visible Light-Excited Nitroxides, Category: chiral-phosphine-ligands, the publication is Journal of Organic Chemistry (2018), 83(18), 10948-10958, database is CAplus and MEDLINE.
Nitroxides can absorb both UV and visible light, and their electron can be excited from the π-bonding orbital to the antibonding π* orbital or the n-bonding orbital to the antibonding π* orbital, resp. Despite the reported UV-induced hydrogen atom transfer (HAT) process, the potential of nitroxides for visible light-excited photosynthesis is underexplored. Here we demonstrate that nitroxide can convert indole to its radical through a visible light-induced HAT process. A chiral phosphoric acid-catalyzed cyclization of the in situ-formed imine radical, followed by trapping by another mol. of nitroxide, provides the product in high yield and enantioselectivity. To highlight the novelty and efficiency of this strategy, an asym. total synthesis of natural product (-)-verrupyrroloindoline was accomplished in 5 steps.
Journal of Organic Chemistry published new progress about 929294-27-9. 929294-27-9 belongs to chiral-phosphine-ligands, auxiliary class Chiral Phosphoric Acids, name is R-3,3′-Bis(2,4,6-triisopropylphenyl)-5,5′,6,6′,7,7′,8,8′-octahydro-1,1′-binaphthyl-2,2′-diyl hydrogenphosphate, and the molecular formula is C50H65O4P, Category: chiral-phosphine-ligands.
Referemce:
https://en.wikipedia.org/wiki/Phosphine_ligand,
Chiral phosphine ligands in asymmetric synthesis. Molecular structure and absolute configuration of (1,5-cyclooctadiene)-(2S,3S)-2,3-bis(diphenylphosphino)butanerhodium(I) perchlorate tetrahydrofuran solvate