Molecular Iodine: An Efficient and Environment Friendly Catalyst for the Synthesis of 3,5-Bis-(arylmethylidene)-tetrahydropyran-4-ones

A rapid, efficient, convenient and cost-effective procedure has been developed for the synthesis of 3,5-bis-(arylmethylidene)-tetrahydropyran-4-ones by the condensation of tetrahydropyran-4-one with araldehydes in the presence of catalytic amount of iodine to obtain the products in good to excellent yield. The reactions work at 25 °C and go to completion within 30–60 min.     

An efficient sonochemical oxidation of benzyl alcohols into benzaldehydes by FeCl3/HNO3 in acetone

Sonochemical oxidation of benzyl alcohols into corresponding aldehydes by FeCl(3)/HNO(3) in acetone at room temperature has been reported. All substrates give good yield of the products within 10-25 min. The reaction of selected substrates were also studied under reflux and at the room temperature. Further, various Lewis acids were used to evaluate their catalytic efficacy.     

Amberlite IR-120 catalyzed,microwave-assisted rapid synthesis of 2-aryl-benzimidazoles

An expeditious synthesis of 2-aryl-benzimidazoles by the condensation of o-phenylenediamine with various araldehydes is described. This greener protocol is catalyzed by Amberlite IR-120, and proceeds efficiently in the absence of any organic solvent under microwave irradiation within 3–5 min.     

An efficient and simple approach for the synthesis of pyranopyrazoles using imidazole (catalytic) in aqueous medium, and the vibrational spectroscopic studies on 6-amino-4-(4'-methoxyphenyl)-5-cyano-3-methyl-1-phenyl-1,4-dihydropyrano[2,3-c]pyrazole using density functional theory

We describe a one-pot four component synthesis of pyranopyroles from aryl aldehydes, ethyl acetoacetate, malononitrile and hydrazine hydrate in the presence of catalytic amounts of an organocatalyst imidazole in water as medium. A plausible mechanism for the formation of imidazole catalyzed pyranopyrazoles has been envisaged. This method is rapid, simple, provides products in good yield, and is eco-friendly. In addition, based on the optimized geometry, the frequency and intensity of the vibrational bands of 6-amino-4-(4'-methoxyphenyl)-5-cyano-3-methyl-1-phenyl-1,4-dihydropyrano[2,3-c]pyrazole were obtained by the density functional theory (DFT) calculations using 6-31G(d,p) basis set. The vibrational frequencies were calculated and the scaled values have been compared with experimental FT-IR and FT-Raman spectra. The observed and the calculated frequencies are found to be in good agreement.     

Amberlite IR-120：一种可重复利用的微波辅助条件下胺类化合物与甲酸N-甲酰化反应的催化剂

 A rapid and practical green route for the N-formylation of amines with formic acid using Amberlite IR-120 as a catalyst is described. This method provides an efficient and much improved modification over the reported methods in terms of yield, reaction time, and work-up procedure. A wide variety of substituents is tolerated, which is not the case for existing procedures.     

Iodine-Catalyzed,Rapid and Efficient,One-Pot Synthesis of 1,2-Dihydro-1-arylnaphtho[1,2e][1,3]oxazine-3-ones Under Solvent-Free Conditions

A mixture of β-naphthol, araldehydes, and urea in the presence of a catalytic amount of iodine as catalyst under solvent-free condition was heated for 5 min on a preheated hot plate to get the corresponding 1,2-dihydro-1-aryl-naphtho[1,2-e][1,3]oxazine-3-ones in very good yield.     

Biotechnological Approaches for Production of Artemisinin,an Anti-Malarial Drug from Artemisia annua L.

Artemisinin is an anti-malarial sesquiterpene lactone derived from Artemisia annua L. (Asteraceae family). One of the most widely used modes of treatment for malaria is an artemisinin-based combination therapy. Artemisinin and its associated compounds have a variety of pharmacological qualities that have helped achieve economic prominence in recent years. So far, research on the biosynthesis of this bioactive metabolite has revealed that it is produced in glandular trichomes and that the genes responsible for its production must be overexpressed in order to meet demand. Using biotechnological applications such as tissue culture, genetic engineering, and bioreactor-based approaches would aid in the upregulation of artemisinin yield, which is needed for the future. The current review focuses on the tissue culture aspects of propagation of A. annua and production of artemisinin from A. annua L. cell and organ cultures. The review also focuses on elicitation strategies in cell and organ cultures, as well as artemisinin biosynthesis and metabolic engineering of biosynthetic genes in Artemisia and plant model systems.     

高效、可重复使用的多相催化剂SiO_2-NaHSO_4用于水中三组分一锅法合成八氢喹唑啉-2,5-二酮(英文)

An environmentally benign method for the synthesis of octahydro-quinazolin-2,5-diones by the reaction of aromatic aldehydes,dimedone,and urea in the presence of SiO2-NaHSO4 is reported.SiO2-NaHSO4 acts as an efficient,mild,and recyclable heterogeneous catalyst to give excellent yields within a short reaction time in water at 60-80℃.     

SiO2-NaHSO4 as an Efficient Reusable Heterogeneous Catalyst for the One-Pot Three-Component Synthesis of Octahydro-quinazolin-2,5-diones in Water

An environmentally benign method for the synthesis of octahydro-quinazolin-2,5-diones by the reaction of aromatic aldehydes,dimedone,and urea in the presence of SiO2-NaHSO4 is reported.SiO2-NaHSO4 acts...