1586794-92-4Relevant articles and documents
Structural reevaluation of the electrophilic hypervalent iodine reagent for trifluoromethylthiolation supported by the crystalline sponge method for x-ray analysis
Vinogradova, Ekaterina V.,Mueller, Peter,Buchwald, Stephen L.
, p. 3125 - 3128 (2014)
Hypervalent iodine λ3-benziodoxoles are common electrophilic transfer reagents known for their enhanced stability compared to their non-cyclic analogues. Herein we present data showing that chlorobenziodoxole reacts with two different thiolate nucleophiles (thiocyanate and trifluoromethylthiolate), resulting in the formation of stable thioperoxy complexes rather than the expected benziodoxole derivatives. We further report a revised structure for the earlier described electrophilic trifluoromethylthiolation reagent (1), which was previously believed to contain the benziodoxole framework. Our findings, which are based on a combination of analytical techniques, including the recently introduced crystalline sponge method for X-ray analysis, unambiguously demonstrate that 1 is a thioperoxy compound both in solution and the solid state. Not-so-hypervalent iodine: Studies of several benziodoxole thiolate derivatives revealed that these species lack the hypervalent iodine motif, instead adopting a thioperoxide configuration. Crystallographic analysis of a liquid trifluoromethylthiolation reagent trapped inside a metal-organic framework provided direct structural proof for the observed phenomenon. These thioperoxide reagents were also shown to be reactive in electrophilic substitution reactions.
