ChemInform Abstract: Electrophilic Substitution Reactions of Indole. Part 20. Use of Montmorillonite Clay K‐10.

Abstract

Electrophilic Substitution Reactions of Indole. Part 20. Use of Montmorillonite Clay K-10. --(BANERJI, J.; DUTTA, U.; BASAK, B.; SAHA, M.; BUDZIKIEWICZ, H.; CHATTERJEE, A.; Indian J.

Bis- and Trisindolylmethanes (BIMs and TIMs)

“…Other factors that prompted new research include the price of catalysts, finding milder reaction conditions, reusability of catalysts, yield of products, reaction rates, simplicity of the workup, green chemistry, etc. Typical protic acids [124][125][126] used to catalyze the reaction include silica sulfuric acid (SSA), 127 oxalic acid, 128,129 zeolites HY 130,131 and ZnY, 132 amberlyst, [133][134][135] p-(ω-sulfonic-perfluoroalkylated)polystyrene (FPS) resins, 136 H 2 SO 4 , 101,137,138 HBr, 139,140 HCl, 68,[141][142][143][144][145][146] 168 PEGsupported sulfonic acid 169 and AcOH-MW, 170 Lewis acids, such as lanthanide resins, 171 zeolite (ZnY), 172 bentonitic clay/ IR, 173 montmorillonite clay K-10, 174,175 [231][232][233] Meldrum's acid/H 2 O/sonoirradiation, 234 SBA-15supported poly(4-styrenesulfonyl(perfluorobutylsulfonyl)imide), 235 carbohydrate-based tolylsulfonyl hydrazines, 236 triphenyl phosphonium perchlorate (TPP), 237 tetrakis[3,5bis(trifluoromethyl)phenyl]borate, 238 hexamethylenetetraaminebromine (HMTAB), 239,…”

“…Other factors that prompted new research include the price of catalysts, finding milder reaction conditions, reusability of catalysts, yield of products, reaction rates, simplicity of the workup, green chemistry, etc. Typical protic acids – used to catalyze the reaction include silica sulfuric acid (SSA), oxalic acid, , zeolites HY , and ZnY, amberlyst, – p -(ω-sulfonic-perfluoroalkylated)polystyrene (FPS) resins, H 2 SO 4 , ,, HBr, , HCl, ,– HCOOH, CH 3 COOH, – p -TsOH, NH 2 SO 3 H, – HBF 4 −SiO 2 , NaHSO 4 −SiO 2 , KHSO 4 , NaHSO 3 , 2KHSO 5 ·KHSO 4 ·K 2 SO 4 (oxone), H 4 SiMo 12 O 40 , H 3 PMo 12 O 40 , H 3 PW 12 O 40 , , H 3+ n PMo 12− n V n O 40 , H 3 PW 12 O 40 −ZrO 2 , H 3 PW 12 O 40 −SiO 2 , −TiO 2 , or −Al 2 O 3 , H 6 P 2 W 18 O 62 , H 14 [NaP 5 W 30 O 110 ])/SiO 2 /sonoirradiation, (NH 4 ) 2 HPO 4 , H 3 PO 4 −SiO 2 , PEG-supported sulfonic acid and AcOH−MW, Lewis acids, such as lanthanide resins, zeolite (ZnY), bentonitic clay/IR, montmorillonite clay K-10, , cerium ammonium nitrate (CAN), nanoceria (CeO 2 ) supported on vinyl pyridine polymer, CeCl 3 ·7H 2 O/glycerin, M(HSO 4 ) x , , KAl(SO 4 ) 2 ·12H 2 O, , AlPW 12 O 40 , AlMe 3 , ZrOCl 2 , ZrOCl 2 ·8H 2 O−SiO 2 , Cp 2 ZrCl 2 , ZrCl...…”

Magnetic Aerogels for Room-Temperature Catalytic Production of Bis(indolyl)methane Derivatives

“…As an alternative to the synthesis under homogeneous catalysis, different approaches based on heterogeneous catalysis have been proposed, including those based on HY and ZnY zeolites [52][53][54], polystyrene-based resins [55], amberlyst [56][57][58], PEG-supported sulfonic acid [59], lanthanide resins [60], and montmorillonite clay K-10 catalysts [61].…”

“…Nanocrystals, however, may suffer from aggregation under reaction conditions, and novel nanocomposite materials based on the immobilization of catalytically active phases on supports such as carbon nanotubes and graphene oxide aerogels have been proposed [67,68]. As an alternative to the synthesis under homogeneous catalysis, different approaches based on heterogeneous catalysis have been proposed, including those based on HY and ZnY zeolites [52][53][54], polystyrene-based resins [55], amberlyst [56][57][58], PEG-supported sulfonic acid [59], lanthanide resins [60], and montmorillonite clay K-10 catalysts [61].…”

Synthesis of Novel Indolo‐Spirocyclic Compounds

“…Normally, these reactions occur in the presence of several types of catalysts, for example, protic or Lewis acids. Protic acids are used to catalyze the reaction, for example, silica sulphuric acid , oxalic acid , zeolites HY and ZnY , amberlyst , HBr , HCl , HCOOH , CH 3 COOH , p ‐TsOH , NaHSO 3 , KHSO 4 , H 3 PO 4 ‐SiO 2 . Lewis acids are lanthanide resins , zeolite (ZnY) , bentonic clay/infrared (IR) , montmorillonite clay K‐10 , cerium ammonium nitrate , ZrCl 4 , IndF 3 , Bi(OTf) 3 , TiCl 4 , and Al(OTf) 3 .…”