Direct Aza‐Diels–Alder Reaction in Water Catalyzed by Layered α‐Zirconium Hydrogen Phosphate and Sodium Dodecyl Sulfate

Abstract

The direct aza-Diels-Alder reaction between 2-cyclohexen-1-one (1) and benzaldimines 2 in water is reported for the first time. The reaction occurs at 30°C, is catalyzed by layered α-zirconium hydrogen phosphate (α-ZrP) and requires the presence of sodium dodecyl sulfate (SDS). The reaction yield is excellent, the reaction is faster and the exo diastereo-

Heteropoly acid-catalyzed three-component aza-Diels–Alder reaction in a continuous micro-flow system

“…As the next 5 step in the optimization process, the effect of reaction temperature on the yield and stereoselectivity was investigated as temperature played an important role in the reaction rate. When the reaction temperature increased to 140°C (Table 3, entry 4), a sharp decrease in the yield was observed, probably due to high 10 temperature could accelerate the decomposition of cycloadducts, which leaded to an open amine revealed by D. Borkin. 13 The data in Table 3 indicated that longer reaction time was necessary to improve the yield.…”

“…General procedure of aza-Diels-Alder reaction with imines in MFS 10 The instrument used in this study was a Bayer sandwich reactor assembled with a T-shaped micromixer and a sandwich microreactor. Two flows were pumped into the micromixer at a set flow rate.…”

Immobilized Palladium Nanoparticles on Zirconium Carboxy-Aminophosphonates Nanosheets as an Efficient Recoverable Heterogeneous Catalyst for Suzuki–Miyaura and Heck Coupling

“…In particular, layered zirconium phosphates and phosphonates can offer a high chemical and thermal robustness together with a facile tunability of their structural features as demonstrated by the large number of applications [15,[29][30][31][32][33][34].…”

N‐Fluorobenzenesulfonimide as Catalyst for the Three‐Component Synthesis of Isoquinuclidines

“…Among them, isoquinuclidine (azabicyclo[2.2.2]octane) has generated considerable attention as a result of their presence in numerous complex natural products and pharmaceuticals such as the alkaloids of dioscorea hispida, dioscorine [1], and the alkaloid ibogaine [2], which possesses the ability to diminish self-administration of cocaine, heroin, and alcohol. The methods reported mainly used metal catalysts such as indium trichloride (InCl 3 ) [3], environmentally friendly bismuth trichloride (BiCl 3 ) [4], and a-zirconium hydrogen phosphate, which allow easy recovery and reuse [5]. The methods reported mainly used metal catalysts such as indium trichloride (InCl 3 ) [3], environmentally friendly bismuth trichloride (BiCl 3 ) [4], and a-zirconium hydrogen phosphate, which allow easy recovery and reuse [5].…”

“…Compound 4 was further purified by recrystallization.3-endo-(4-Nitrophenyl)-2-(4-methoxyphenyl)-2-aza-bicyclo [2.2.2]octan-5-one (4a)[5]. The crude material was purified via flash column chromatography of silica gel (petroleum ether/AcOEt = 12:1 to 8:1) to give 4 and 5.…”