Heterogeneous Catalysts for the One-Pot Synthesis of Chemicals and Fine chemicals

Abstract

[EN] It is apparent that intensi¿cation in chemical and most speci¿cally in catalytic processes is of growing in interest among researchers. This is not only because of the potential economical impact if translated into industrial application, Table 24. One-Pot r,r-Dialkylation of Nitriles using Metal/HTsa aReaction conditions: Method A: (i) nitrile (1 mmol) carbonyl compounds (1 mmol), Pd/HT (0.1 g; Pd 0.01 mmol), toluene (3 mL), 2 h, 80 °C, Ar. After completion of the aldol reaction, the reaction mixture was further treated at 60 °C for 1 h under H2 (1 atm). (ii) Ole¿n (1.5 mmol), 5 h, 70 °C, Ar. Method B: (i) nitrile (1 mmol), alcohol (2 mL), Ru/HT (0.15 g; 0.0075 mmol), 180 °C, 20 h, Ar. (ii) Ole¿n (3 mmol), DMSO (2 mL), 150 °C, 1 h, Ar. bOverall yield based on nitrile. cAt 110 °C, 12 h for Michael addition. dA solution of methyl vinyl ketone (1.5 mmol) in toluene (2 mL) was slowly added over 6 h and further reacted for 4 h. eDMF (3 mL) was used as solvent. fDMF (3 mL) was used as solvent for Michael addition. gDetermined by GC by an internal standart. Scheme 155. Sequential Acetal Hydrolysis Followed by Knoevenagel Condensation and Subsequent Hydrogenation Scheme 156. Sequential Acetal Hydrolysis Followed by Aldol Type Condensations Heterogeneous Catalysts for One-Pot Synthesis Chemical Reviews, 2011, Vol. 111, No. 2 1127but also because it is challenging and attractive to achieve the molecular design of a catalyst that allows cascade type reactions to be performed.