Asymmetric synthesis of sulfinyl-substituted arene chromium tricarbonyl complexes
Davies SG., Loveridge T., Teixeira MFCC., Clough JM.
The synthesis of (SRSs[(phenylsulfinyl)benzene] chromium tricarbonyl 5 and (SRSs)-[(p-tolylsulfiny))benzene] chromium tricarbonyl 6 is achieved via a nucleophilic displacement reaction between the anion derived from (benzene) chromium tricarbonyl 9 and a suitable sulfinate ester. Replacing the sulfinate ester with a chiral sulfinyl-transfer reagent allows the isolation of the non-racemic sulfinyl-substituted complexes with good enantioselectivities (ee 80-89%) under optimised conditions. The use of Kagan's cyclic sulfite methodology for the synthesis of an enantiomerically pure tert-butylsulfinyl complex is unsuccessful, but results in the identification of a novel fragmentation - isomerisation process of the intermediate sulfinate. © The Royal Society of Chemistry 1999.