Pseudotetrahedral Polyhaloadamantanes as Chirality Probes: Synthesis, Separation, and Absolute Configuration
摘要:
Pseudotetrahedral, conformationally as well as configurationally stable 1-bromo-3-chloro-5-fluoro- (4) and 1-bromo-3-chloro-5-fluoro-7-iodoadamantane (5) (and some related compounds) were prepared by our recently devised phase-transfer catalytic halogenation protocol; the optical antipodes of 4 were separated by HPLC on chiral phase in ee > 99%, and the absolute configurations were assigned by matching observed and computed circular dichroism spectra. Structure 5 is the first chiral aliphatic hydrocarbon containing all stable (nonradioactive) halogens; its structure was proven by NMR spectroscopy and by X-ray crystal data. We emphasize that the combination of experiment and theory is very powerful in assigning absolute configurations even for molecules without typical chromophors, with small values for the optical rotation, and without an atom at the stereogenic center.
Perkins,R.R.; Pincock,R.E., Canadian Journal of Chemistry, 1978, vol. 56, p. 1269 - 1272
作者:Perkins,R.R.、Pincock,R.E.
DOI:——
日期:——
Pseudotetrahedral Polyhaloadamantanes as Chirality Probes: Synthesis, Separation, and Absolute Configuration
作者:Peter R. Schreiner、Andrey A. Fokin、Oliver Lauenstein、Yoshio Okamoto、Tsuneki Wakita、Christopher Rinderspacher、Gregory H. Robinson、Jason K. Vohs、Charles F. Campana
DOI:10.1021/ja0274195
日期:2002.11.1
Pseudotetrahedral, conformationally as well as configurationally stable 1-bromo-3-chloro-5-fluoro- (4) and 1-bromo-3-chloro-5-fluoro-7-iodoadamantane (5) (and some related compounds) were prepared by our recently devised phase-transfer catalytic halogenation protocol; the optical antipodes of 4 were separated by HPLC on chiral phase in ee > 99%, and the absolute configurations were assigned by matching observed and computed circular dichroism spectra. Structure 5 is the first chiral aliphatic hydrocarbon containing all stable (nonradioactive) halogens; its structure was proven by NMR spectroscopy and by X-ray crystal data. We emphasize that the combination of experiment and theory is very powerful in assigning absolute configurations even for molecules without typical chromophors, with small values for the optical rotation, and without an atom at the stereogenic center.