3023-49-2Relevant articles and documents
First chemoenzymatic synthesis of (R)- and (S)-1-(9H-fluoren-9-yl)ethanol
Borowiecki, Pawel,Balter, Sylwia,Justyniak, Iwona,Ochal, Zbigniew
, p. 1120 - 1126 (2013/10/08)
A simple chemoenzymatic synthesis of 1-(9H-fluoren-9-yl)ethanol stereoisomers is described. The enantiomers were resolved by a kinetically controlled transesterification with vinyl acetate in the presence of commercially available lipases. High-throughput screening and subsequent exhaustive investigation of the utility of the lipases in a stereoselective process of introducing chirality have been carried out. Lipase A from Candida antarctica as a cross-linked aggregate (CAL-A-CLEA) was the most efficient enzyme for the resolution of the title compound providing (S)-1-(9H-fluoren-9- yl)ethanol and its (R)-acetate in enantiopure form (>99% ee). Under mild reaction conditions, excellent enantioselectivity (E = 407), and good isolated yields of the products were obtained.
Laser flash photolysis of 9-diazofluorene in low-temperature glasses
Ruzicka, Jan,Leyva, Elisa,Platz, Matthew S.
, p. 897 - 905 (2007/10/02)
The laser flash photolysis of 9-diazofluorene was investigated in several viscous organic glasses at low temperature. The data indicate that triplet fluorenylidene reacts with "soft warm" glasses by classical H atom abstraction, but the mechanism changes to quantum mechanical tunneling in colder and more rigid matrices.
Separation of Amino Acid Enantiomers and Chiral Amines Using Precolumn Derivatization with (+)-1-(9-Fluorenyl)ethyl Chloroformate and Reversed-Phase Liquid Chromatography
Einarsson, Stefan,Josefsson, Bjoern,Moeller, Per,Sanchez, Domingo
, p. 1191 - 1195 (2007/10/02)
A new chiral reagent (+)-1-(9-fluorenyl)ethyl chloroformate (FLEC) was synthesized for separation of amino acid enentiomers and optically active amines.Highly fluorescent diastereomers of amino acids were obtained without racemization within 4 min at room temperature.The derivatives have favorable chromatographic properties, which is demonstrated by a reversed-phase separation of the D and L form of 17 primary amino acids in a single run.The secondary amino acids were resolved separately at a lower pH and can be determined without interferences from primary amino acids.The stability of the derivatives permitted confirmation studies with gas chromatography-mass spectrometry.
