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Cercosporin-Photocatalyzed [4+1]- and [4+2]-Annulations of Azoalkenes Under Mild Conditions
Published on: July 17, 2020
(R)-4-(4-Aminophenyl)-2,2,4-trimethylchroman and (S)-4-(4-aminophenyl)-2,2,4-trimethylthiachroman
Christopher S Frampton1, David D MacNicol, Derek R Wilson
1Pharmorphix Solid State Services, A Sigma-Aldrich Company, 250 Cambridge Science Park, Milton Road, Cambridge CB4 0WE, England. chris.frampton@sial.com
Abstract:
The title compounds, C(18)H(21)NO and C(18)H(21)NS, in their enantiomerically pure forms are isostructural with the enantiomerically pure 4-(4-hydroxyphenyl)-2,2,4-trimethylchroman and 4-(2,4-dihydroxyphenyl)-2,2,4-trimethylchroman analogues and form extended linear chains via N-H···O or N-H···S hydrogen bonding along the [100] direction. The absolute configuration for both compounds was determined by anomalous dispersion methods with reference to both the Flack parameter and, for the light-atom compound, Bayesian statistics on Bijvoet differences.
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