Structural Reevaluation of the Electrophilic Hypervalent Iodine Reagent for Trifluoromethylthiolation Supported by the Crystalline Sponge Method for X‐ray Analysis

Abstract

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.

Direct Trifluoromethylthiolation and Perfluoroalkylthiolation of C(sp2)H Bonds with CF3SO2Na and RfSO2Na

“…We also monitored the reaction of 3a with 2b and (EtO) 2 P(O)H (Figure 3, V), and were able to detect 4a after 3hours,a long with as mall amount of CF 3 SSCF 3 .T his result suggests path A( see Scheme 3) is possible,but not as efficient as path B. Only 19 FNMR data for RSO n CF 3 compounds were found in the literature, [11,28] and no information for CF 3 S(O)H and CF 3 SOH is available.T he 19 FNMR data of related compounds are listed in Table 3f or comparison.…”

“…[21] CuCl serves as both areducing agent for CF 3 SO 2 Na and also acatalyst for CF 3 SSCF 3 . [11] CF 3 SOH (9) Scheme 3. Proposed mechanism for CF 3 SO 2 Na trifluoromethylthiolation.…”

“…[5] Since they are highly reactive and hard-to-handle gaseous chemicals,aseries of CF 3 S-based reagents,i ncluding quaternary ammonium Me 4 NSCF 3 , [6] metallic CuSCF 3 and AgSCF 3 , [7] and the shelf-stable chemicals 1a-f,h ave been developed for trifluoromethylthiolation ( Figure 1). [8][9][10][11][12][13] However,t hey have to be prepared by trifluoromethylthiolation or trifluoromethylation reactions,and could be very expansive.In2009, the group of Magnier reported aCF 3 SO 2 K-initiated trifluoromethylation reaction. As mall amount of trifluoromethylthiolation product was detected in the reaction mixture.…”

Cyclic Hypervalent Iodine Reagents for Atom‐Transfer Reactions: Beyond Trifluoromethylation

“…However, Buchwald and coworkers later demonstrated that the reagent was in fact a thioperoxide. [45] …”

An Iodine‐Vapor‐Induced Cyclization in a Crystalline Molecular Flask

“…[8] This provides an anchor for postsynthetic modification (PSM) reactions that occur in the solid state and can be monitored crystallographically. [9][10][11][12][13][14][15] In the absence of an aromatic handle,m atching of the spatial dimension of the pore cavity is also av iable strategy to observe guests using crystallographic methods.This approach has been used to probe photoswitching, [16] change conformational isomerization ratios, [17,18] observe unusual molecular interactions, [19] and identify organic species, [20,21] with the notable advantage of requiring only nanogram to microgram quantities of the analyte.[3]Arange of chemical reactions have been observed within CMFs,i ncluding the conversion of amines into imines, [9,10] Huisgen cycloadditions, [11] Diels-Alder reactions, [14] and metal-catalyzed methylation [12] and bromination.[15] All of these processes occurred upon immersing aC MF that contained am odified intercalated triphenylene moiety into solutions with appropriate chemical reactants.O nly one example of achemical reaction combining gas-phase reagents and aCMF has been reported, and involved the conversion of avinyl group into epoxidation/oxidation products with the aid of ar adical initiator. [14] This reaction, however,r equired loading of the CMF with 2,2'-azobis(isobutyronitrile) and the use of forcing conditions,whereby an emulsion of crystals was heated at 80 8 8Cf or 24 hours in air.T ot he best of our knowledge,a ttempting chemical transformations in CMFs using gas-phase reagents in the absence of solvents is unprecedented.…”