Alkyl‐ and Arylthiolation of Aryl Halides Catalyzed by Fluorinated Bis‐Imino‐Nickel NNN Pincer Complexes [NiCl₂{C₅H₃N‐2,6‐(CHNAr_f)₂}]

Abstract

Abstract:The synthesis of bis-imino nickel(II) NNN pincer complexes of the type [NiCl 2 {C 5 H 3 N-2,6-(CHNAr f ) 2 }]; Ar f ¼ C 6 H 3 -2,3-F 2 (1), C 6 H 3 -2,5-F 2 (2), C 6 H 3 -3,4-F 2 (3), C 6 H 3 -3,5-F 2 (4), C 6 H 2 -2,3,4-F 3 (5), C 6 H 2 -2,3,6-F 3 (6), C 6 H 2 -2,4,5-F 3 (7), C 6 H 2 -2,4,6-F 3 (8), has been achieved and their reactivity in alkyl-and arylthiolation reactions of halobenzenes examined. The use of fluorinated substituents Ar f on the imines has allowed the tuning of the electronics in these complexes and the influence of these substituents and those of the disulfides in the thiolation reactions have been analyzed.

BF3·SMe2 for Thiomethylation, Nitro Reduction and Tandem Reduction/SMe Insertion of Nitrogen Heterocycles

“…[2][3][4][5][6][7][8][9] Although thiolate salts are good nucleophiles, these types of reagents suffer from a range of drawbacks including volatility, instability, toxicity, and strong, unpleasant odors. [10][11][12][13] Disulfides can also be used for the thiomethylation of aryl halides using nickel catalysts and zinc [14][15][16][17][18][19][20] (Scheme 1a) or aryl diazaonium salts [21] and boronic acids [22] (Scheme 1c) under radical conditions although they are also known to be highly odorous. Recently, DMSO has emerged as an attractive thiomethyl source for the functionalization of a range of substrates [23][24][25][26][27][28][29] (Scheme 1a and Scheme 1b) however, these reactions require high temperatures as well as the use of stoichiometric amounts of copper salts.…”

Pincer-type bis(carbene)-derived complexes of nickel(II): Synthesis, structure, and catalytic activity

“…Various types (e.g., PCP-, NCN-, CNC-) of pincer complexes of transition metals have been reported to date; among them, palladium-pincer complexes have been widely investigated and employed as catalysts for cross-coupling reactions [10][11][12][13][14][15]. Much less attention has been paid to the nickel-pincer complexes [16][17][18][19][20][21][22], although the use of nickel catalysts instead of palladium catalysts sometimes offers advantages, such as cost effectiveness and distinct catalytic abilities [23][24][25][26][27][28][29][30][31][32][33]. In this regard, we recently reported the synthesis of a CNC-type pincer complex of nickel 1 (Fig.…”

Metal-Free, DTBP-Mediated Methylthiolation of Arylboronic Acids with Dimethyldisulfide

“…Notably, in these cases, the respective desired products were obtained in good yields while keeping fluoro, chloro, bromo, and iodo functional groups intact, which could conveniently extend the scope of further functionalization on the phenyl ring (Table 2, entries 7-13). Phenylboronic acids with electronwithdrawing substituents such as COMe and CN groups were good coupling partners, whereas a slight decrease in the yield of methylthiolation product was observed for phenylboronic acid with a strong electron-withdrawing nitro group (Table 2, entries [14][15][16][17]. Moreover, compared with para-substituted arylboronic acids, ortho-and metasubstituted substrates could also be well tolerated, albeit generating the desired products in moderate yields.…”