An efficient metal-free sulfenylation of indoles with disulfides has been developed, leading to 3-arylthioindoles in moderate to excellent yields. Furthermore, bromosulfenylation of indoles with disulfides has been realized for the first time providing a new family of 2-bromo-3-arylthioindole derivatives in good yield by the one-pot construction of C À S and C À Br bonds. It is noteworthy that the system enables the use of both the RS moieties in RSSR and shows a broad functional group tolerance.

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The process can be applied to a broad spectrum of diaryl dichalcogenides in the presence of inexpensive Rongalite and in the absence of metal catalysts.The products, versatile intermediates in natural product synthesis, are available with excellent yields within a short reaction time.

A Metal-Free Sulfenylation and Bromosulfenylation of Indoles: Controllable Synthesis of 3-Arylthioindoles and 2-Bromo-3-arylthioindoles. -The amount of NBS [cf. A) versus B)] determines the reaction course. The synthetic potential of the method is demonstrated with some transformations of product (IVd). -(HUANG, D.; CHEN*, J.; DAN, W.; DING, J.; LIU, M.; WU, H.; Adv. Synth. Catal. 354 (2012) 11-12, 2123-2128, http://dx.doi.org/10.1002/adsc.201200227 ; Coll. Chem. Mater. Eng., Wenzhou Univ., Wenzhou 325035, Peop. Rep. China; Eng.) -R. Steudel 10-121