Reversible Stereodivergent Cycloaddition of Racemic Helicenes to [60]Fullerene: A Chiral Resolution Strategy
作者:Rosa M. Girón、Jiangkun Ouyang、Ludovic Favereau、Nicolas Vanthuyne、Jeanne Crassous、Salvatore Filippone、Nazario Martín
DOI:10.1021/acs.orglett.8b00256
日期:2018.4.6
[60]Fullerene and its rarely explored reversible covalent chemistry have been harnessed as an efficient alternative for the chiral resolution of racemates. By using only catalytic amounts of chiral agents, stereodivergent 1,3-dipolar cycloadditions of racemic helicenes onto [60]fullerene were carried out. The formed helicene/fullerene diastereomers were easily separated by conventional chromatography
The synthesis of 2-bromo[6]helicene was revised and improved up to 51% yield. Its reactivity was thoroughly investigated, and a library of 17 different carbon, boron, nitrogen, phosphorus, oxygen and sulfur substituted derivatives was prepared. The racemization barrier for 2-bromo[6]helicene was determined, and the usage of enantiomers in the synthesis of optically pure helicenes was rationalized.
Porphyrin- and Bodipy-helicene conjugates: syntheses, separation of enantiomers and chiroptical properties
作者:Vincent Silber、Marion Jean、Nicolas Vanthuyne、Natalia Del Rio、Paola Matozzo、Jeanne Crassous、Romain Ruppert
DOI:10.1039/d3ob01459b
日期:——
The synthesis of several new compounds containing a chromophore and a helicenic moiety is reported. The preparation, characterisation and some physico–chemical studies are detailed. In particular, the two enantiomers of several chiral molecules of this type were separated by chiral HPLC (both analytically and in a preparative way) and their racemisation rates were determined for short-lived species