Introduction of a Recyclable Basic Ionic Solvent with Bis-(NHC) Ligand Property and The Possibility of Immobilization on Magnetite for Ligand- and Base-Free Pd-Catalyzed Heck, Suzuki and Sonogashira Cross-Coupling Reactions in Water

Catalytic filtration: efficient C-C cross-coupling using Pd(II)-salen complex-embedded cellulose filter paper as a portable catalyst

“…[15][16][17]44 The observations obtained from the control experiments in this study (Table 5), were also in complete agreement with the previous reports. [15][16][17]44 As shown in Table 5 (entries 1,2), Pd IIsalen complex 5 and Pd II -salen-[IM]I, did not give any efficiency for the Sonogashira model reaction; While 60% efficiency was found in the presence of Pd II -salen-[IM]OH for 10a. Scheme 3 shows the proposed mechanism in accordance with the literature and observations in this work.…”

“…On the other hand, due to the higher efficiency of aryl halides bearing electron withdrawing group compared to the halides with electron donating substituent (Tables 2-4), it was suggested that the reaction proceed from the path including oxidative-addition and reductive-elimination steps in agreement with the literature. 18,47,55 As shown in Tables 2-4, the efficiency as well as the ltration time and cycles for aryl halides were as order of I > Br > Cl, and even for some aryl chlorides no efficiency was observed (Table 2, entry 14; Table 3, entries 13,14; and Table 4, entries [15][16][17]. These results were a strong evidence for the oxidative-addition and reductive-elimination steps.…”

“…In rst, 2-hydroxy-5-chloromehyl benzaldehyde (SA-5-ClM) was prepared according to the previously reported procedures (purple crystals, 97% isolated yield). [15][16][17][18] Then, in order to synthesis of 2-hydroxy-5-(iodomethyl)benzaldehyde (named as SA-5-IM briey), SA-5-ClM (2.0 mmol) was dissolved in dry acetone (20 mL), then 4.0 mmol of Na I was added to the mixture. The mixture was stirred at ambient temperature for 2.0 h. Then, the mixture was ltrated by a simple Whatman No.1 lter paper to remove of NaCl salts, then SA-5-IM product was obtained by removing the solvent at room temperature (88% isolated yield).…”

“…14 On the other hand, research has shown that imidazolium tails bearing hydroxide counter ions in the heterogeneous catalytic systems have a high basicity towards coupling reactions (as a basic reagent), so that their presence in the catalyst structure in the coupling reactions causes the reaction to take place in the absence of any basic reagent. [15][16][17][18] In this way, in the present work, a modied cellulose lter paper was prepared by immobilization of a Pd(II) salen complex bearing imidazolium hydroxide tails on a silica treated cellulose lter paper, as a portable catalytic system (Scheme 1). Scheme 1c shows an original picture of the resulting cellulose lter paper aer surface modication.…”

Transfer hydrogenation of nitroarenes using cellulose filter paper-supported Pd/C by filtration as well as sealed methods

“…In order to study the catalytic activity of Pd centers on the surface of the filter paper as a heterogeneous catalyst, the Pd centers were poisoned with an excess amount of Hg(0). 57 For this purpose, the catalytic filter paper in ethanolic solution of metallic mercury (0) (240 mmol) was shaken in a Petri dish for 2 h and then used in the nitrobenzene reduction to aniline in the presence of ammonium formate after complete drying. The results did not show any catalytic activity for 190 min (four consecutive filtrations) on the filter paper.…”