Iron(III) Chloride: A Versatile Catalyst for the Practical Synthesis of 3-Sulfenylindoles

Abstract

The direct sulfenylation of indoles with aromatic thiols has been accomplished in the presence of 20 mol% of FeCl 3 in refluxing acetonitrile to produce 3-arylthioindoles in relatively good to excellent yields and with high selectivity. This method works even with 2-unsubstituted indoles.

Convenient and Efficient Synthesis of Functionalized 2-Sulfenylindoles

“…There are many efficient methodologies for the synthesis of sulfenylindoles reported in the literature [ 20 , 21 , 22 , 23 , 24 , 25 ]. Among them, the direct sulfenylation of indoles is one of the most efficient and common strategies [ 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 ]. Due to the nucleophilic properties of an indole ring, it can be easily functionalized at the C3 position by using a variety of electrophiles.…”

Selective synthesis of 3‐Selanylindoles from Indoles and Diselenides using IK/mCPBA system

“…The indole nucleus is ubiquitous in a wide range of natural products, pharmaceuticals and fine chemicals, and consequently, much attention has been paid to the synthesis of substituted indoles . 3‐Selanylindoles is a significant class of indole compounds due to they are bioactive and potentially useful as valuable synthetic intermediates . There are some methods for synthesis of 3‐selanylindoles, besides the electrophilic cyclization of 2‐alkynylanilines, the main route for obtaining them is the use of easily available indole as starting material.…”

FeF3/I2-Catalyzed Synthesis of 4-Chalcogen-Substituted Arylamines by Direct Thiolation of an Arene C-H Bond

“…10 For example, Yadav and coworkers reported an iron(III) chloride catalyzed direct thiolation of indoles with thiols. 11 We have also developed an iodine-promoted iron-catalyzed chalcogenation of indoles with disulfides or diselenides (Scheme 1, Equation 1. 12 As a continuing interest in the synthetic utility of disulfides, 12,13 we sought to extend these catalytic systems to the thiolation of arylamines.…”

“…The amount of I 2 affected the reaction: a lower yield was observed when the amount of I 2 was increased to 20 mol% or decreased to 5 mol% (entries 9 and 10). Among the effects of solvent and reaction temperature examination, the reaction in MeCN at 80°C gave the best results (entries [11][12][13][14][15]. Finally, the loading of FeF 3 was evaluated.…”

“…8 Recently, the direct functionalization of arene C-H bond has received attention because of its potential low cost and environmentally benign features. 8i,j, [9][10][11][12] Thus, C-S bond forming reactions through C-H functionalization of arene or heteroarene with various sulfur-containing reagents have been investigated. 10 For example, Yadav and coworkers reported an iron(III) chloride catalyzed direct thiolation of indoles with thiols.…”