Carbon-Heteroatom Bond-Forming Reductive Elimination. Mechanism, Importance of Trapping Reagents, and Unusual Electronic Effects during Formation of Aryl Sulfides

Palladium‐Catalyzed Amination of Aryl Halides and Sulfonates

“…This trend implies that the more nucleophilic the amido group, the faster the elimination process. Variation of the aryl group led to similar results as those seen in an extensive study of the electronic aspects of CaS bond-forming eliminations of sulfides [54]. The data for electronic effects on sulfide and amine eliminations ( Figure 4) show that electron-withdrawing groups accelerate the reductive elimination process and that substituents with large s R values affect the reaction rates more than substituents with large s I values.…”

“…Particularly useful examples are the conversions of binaphthol to binaphthylphosphines via the triflate intermediate in the presence of palladium and nickel catalysts [52,53]. The soft, nucleophilic character of thiolates and phosphides favors formation of the palladium thiolate or phosphide complexes and reductive elimination [54] of phosphine and sulfide. stemmed from Kosugi's initial finding [86,87] that palladium complexes catalyze the formation of arylamines from tin amides and aryl halides.…”

Organometallic Approaches to Carbon–Sulfur Bond Formation

“…Pd(OAc) 2 /Josiphos mediated thioetherification [14,15] The Josiphos ligand was selected based on detailed mechanistic investigations of reductive elimination from Pd-thiolate species [83,85,86,106,111]. Two factors were identified as crucial for the observed reactivity: the strong electron releasing nature of this bisphosphine ligand and the suppression of formation of less-reactive bridging thiolate complexes due to the steric demands of the ligand.…”

Highly Efficient and Functional‐Group‐Tolerant Catalysts for the Palladium‐Catalyzed Coupling of Aryl Chlorides with Thiols

“…[33,34] Palladium thiolates form easily and undergo relatively fast reductive eliminations with aryl groups. [35][36][37] Thus, the current limitations on the aromatic thiation could result from the notorious sensitivity of late metal catalysts to substrates containing reactive sulfur functionality. The lifetime and concentrations of the catalysts used for the coupling of haloarenes with thiols is likely to be limited by factors such as displacement of dative ligands by thiolates to form anionic thiolate complexes I or the formation of bridging thiolate complexes II that undergo slow reductive elimination ( Figure 1).…”