Molybdatophosphoric acid as an efficient catalyst for the catalytic and chemoselective oxidation of sulfides to sulfoxides using urea hydrogen peroxide as a commercially available oxidant

An efficient procedure for the chemoselective oxidation of alkyl (aryl) sulfides to the corresponding sulfoxides using urea hydrogen peroxide (UHP) in the presence of a catalytic amount of molybdatophosphoric acid at room temperature is described. The advantages of described method are: generality, high yield and chemoselectivity, short reaction time, low cost and compliment with green chemistry protocols

JSCS–3962 Original scientific paper

acid as an efficient catalyst for the catalytic and chemoselective oxidation of sulfides to sulfoxides using urea hydrogen peroxide as a commercially available oxidan

Improved Gravitational Search Algorithm (GSA) Using Fuzzy Logic

Researchers tendency to use different collective intelligence as the search methods to optimize complex engineering problems has increased because of the high performance of this algorithms. Gravitational search algorithm (GSA) is among these algorithms. This algorithm is inspired by Newton's laws of physics and gravitational attraction. Random masses are agents who have searched for the space. This paper presents a new Fuzzy Population GSA model called FPGSA. The proposed method is a combination of parametric fuzzy controller and gravitational search algorithm. The space being searched using this combined reasonable and accurate method. In the collective intelligence algorithms, population size influences the final answer so that for a large population, a better response is obtained but the algorithm execution time is longer. To overcome this problem, a new parameter called the dispersion coefficient is added to the algorithm. Implementation results show that by controlling this factor, system performance can be improved

Solvent-Free Synthesis of 1,8-Dioxo-octahydroxanthenes and 14-Aryl-14H-dibenzo[a,j]xanthenes using Saccharin Sulfonic Acid as an Efficient and Green Catalyst

Saccharin sulfonic acid (SaSA) is utilized as a highly efficient, green and inexpensive sulfonic acid-containing catalyst for the following one-pot multi-component organic transformations: (i) the condensation of dimedone (2 eq.) with aromatic aldehydes (1 eq.) leading to 1,8-dioxo-octahydroxanthenes, and (ii) the reaction of 2-naphthol (2 eq.) with arylaldehydes (1 eq.) leading to 14-aryl-14H-dibenzo[a,j]xanthenes. In these protocols, the title compounds are produced in high to excellent yields and in relatively short reaction times under solvent-free conditions