Efficient Construction of Symmetrical Diaryl Sulfides via a Supported Pd Nanocatalyst-Catalyzed C-S Coupling Reaction

Abstract

Aryl sulfides play an important role in pharmaceuticals, biologically active molecules and polymeric materials. Herein, a general and efficient protocol for Pd@COF-TB (a kind of Pd nanocatalyst supported by a covalent organic framework)/DIPEA-catalyzed one-pot synthesis of symmetrical diaryl sulfides through a C-S coupling reaction from aryl iodides and Na2S2O3 is developed. More importantly, the addition of N,N-diisopropylethylamine (DIPEA) can not only enhance the catalytic activity of a Pd@COF-TB nanocatalyst, but also effectively inhibit the formation of biphenyl byproducts, which are a product of Ullmann reaction. Besides, it has been confirmed that the aryl Bunte salts generated in situ from Na2S2O3 and aryl iodides are the sulfur sources involved in this C-S coupling reaction. With the strategy proposed in this work, a variety of symmetrical diaryl sulfides could be obtained in moderate to excellent yields with a high tolerance of various functional groups. Moreover, a possible mechanism of this Pd nanoparticle-catalyzed C-S coupling reaction is proposed based on the results of controlling experiments.

AGA8 supported Cu(I) nanoclusters as in situ generated catalysts for room temperature C‐S coupling reactions in water

“…Based on the experimental results and previous literature reports, 20,[23][24][25][26] A reasonable mechanistic explanation is depicted for the micelle-derived Cu(I) nanoclusters catalyzed C-S coupling reactions in water (Figure 6). Initially, the surfactant AGA8 aggregated and formed spherical micelles in water to separate and encapsulate organic substrates from the aqueous solution.…”

AGA8 Supported Cu(I) Nanoclusters as In-situ Generated Cata-lysts for Room Temperature C-S Coupling Reactions in Water

“…3) In the presence of radical scavengers like 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO), a significant amount of dibenzyl disulfide was still isolated (Scheme 2 eq 3), which refutes the involvement of radical species in the reaction pathway. Based on the experimental results and previous literature reports [20,[22][23][24][25] , A reasonable mechanistic explanation is depicted for the micelle-derived Cu(I) nanoclusters catalyzed C-S coupling reactions in water (Figure 2). Initially, the surfactant AGA8 aggregated and formed spherical micelles in water to separate and encapsulate organic substrates from the aqueous solution.…”