Benzylation of β-dicarbonyl compounds and 4-hydroxycoumarin using TMSOTf catalyst: a simple, mild, and efficient method

Phase controlled synthesis of bifunctional TiO2 nanocrystallites viad-mannitol for dye-sensitized solar cells and heterogeneous catalysis

“…In the presence of 20 mg of A-TiO 2 catalyst, at 70 C for a reaction time of 4.5 h, 95% yield was obtained, which is one of the maximum values, so far, reported in the literature. [38][39][40][41][42][43][44][45][46][47] It was observed that aer extended reaction time and high temperature, the reaction did not proceed in the forward direction. In our study, 20 mg of A-TiO 2 catalyst under heat/visible light and solvent free conditions demonstrated a notable product yield of 95% with stipulated time period of 4.5 h. Similarly, the nature of the solvent can interrupt the reaction environment by affecting the catalytic stability, solubility, and rate of the reaction.…”

Alcohols in direct carbon-carbon and carbon-heteroatom bond-forming reactions: recent advances

“…The use of trimethylsilyl trifluoromethanesulfonate (TMSOTf) as an efficient catalyst for direct benzylation of 1,3-dicarbonyl compounds with various benzylic alcohols in CH 3 NO 2 was described by Lalitha et al 195 Kaneda et al developed an environmentally benign synthetic approach to nucleophilic substitution reactions of alcohols catalyzed by proton-and metal-exchanged montmorillonites (H-and M n+ -mont). Anilines, amides, indoles 1,3-dicarbonyl compounds and allylsilane acted as a nucleophile for the H-mont-catalyzed substitutions of alcohols, for the formation of various C-N and C-C bonds.…”

SO<sub>4</sub><sup>2-</sup>/SnO<sub>2</sub>-Catalyzed C3-alkylation of 4-hydroxycoumarin with secondary benzyl alcohols and <i>O</i>-alkylation with <i>O</i>-acetyl compounds

“…A few methods that have been reported for the C3-alkylation of 4-hydroxycoumarin so far with alcohols including strong acids, such as HCl, H 2 SO 4 , etc. [20][21][22], Yb(OTf) 3 [23], FeCl 3 ·6H 2 O [24], Amberlite IR-120 [25], molecular iodine [26], Bi(OTf) 3 [27], Fe(ClO 4 ) 3 ·xH 2 O [28], TMSOTf [29], Bi(NO 3 ) 3 ·5H 2 O/Ionic liquid system [30], Ir-Sn bimetallic system [31]. However, processes involving conventional acids, are inherently associated with problems such as high toxicity, corrosion, catalyst waste and difficulty in separation and recovery.…”