Photocatalytic oxidation of organic dyes and pollutants in wastewater using different modified titanium dioxides: A comparative review

Bromination is one of the most important transformations in organic synthesis and can be carried out using bromine and many other bromo compounds. Use of molecular bromine in organic synthesis is well-known. However, due to the hazardous nature of bromine, enormous growth has been witnessed in the past several decades for the development of solid bromine carriers. This review outlines the use of bromine and different bromo-organic compounds in organic synthesis. The applications of bromine, a total of 107 bromo-organic compounds, 11 other brominating agents, and a few natural bromine sources were incorporated. The scope of these reagents for various organic transformations such as bromination, cohalogenation, oxidation, cyclization, ring-opening reactions, substitution, rearrangement, hydrolysis, catalysis, etc. has been described briefly to highlight important aspects of the bromo-organic compounds in organic synthesis.

Use of Bromine and Bromo-Organic Compounds in Organic Synthesis

The Reformatsky reaction in organic synthesis. Recent advances

Pectin is a polymer with a core of alternating α-1,4-linked d-galacturonic acid and α-1,2-l-rhamnose units, as well as a variety of neutral sugars such as arabinose, galactose, and lesser amounts of other sugars. Currently, native pectins have been compared to modified ones due to the development of natural medicines and health products. In this review, the results of a study of the bioactivity of pectic polysaccharides, including its various pharmacological applications, such as its immunoregulatory, anti-inflammatory, hypoglycemic, antibacterial, antioxidant and antitumor activities, have been summarized. The potential of pectins to contribute to the enhancement of drug delivery systems has been observed.

Biological Activity and Pharmacological Application of Pectic Polysaccharides: A Review.

Methods for direct alkene diamination, new & old

Acetylacetone reacted with formaldehyde and thiols in aqueous medium or in the presence of 0.1 equiv of sodium hydroxide to give the corresponding 3-[(alkylsulfanyl)methyl]pentane-2,4-diones which exist in solution as mixtures of diketone and enol tautomers. Four-component condensation of acetylacetone with formaldehyde, methanethiol, and sodium sulfide, depending on the reaction time, led to the formation of a mixture of 1,1-bis(methylsulfanylmethyl)propan-2-one with 1,1′-{3-[(methylsulfanyl)methyl]tetrahydro-2H-thiopyran-3,5-diyl}diethanone or with 8-methyl-5-(methylsulfanylmethyl)-3-thiabicyclo[3.3.1]non-7-en-6-one.

Condensation of acetylacetone with formaldehyde and thiols

The acetalization of phenyl 1-thio-α-L-arabinopyranoside with 2,3-butanedione in the medium of MeOH-CH(OMe)3-CSA proceeded with the prevailing formation of the corresponding 3,4-bisacetal that further was converted in compounds, which were regio- and stereoisomers of disaccharide block of OSW-1.

Disaccharide blocks for analogs of OSW-1

The reaction of 2-(2-cyclopentenyl)anilines with I2 in the presence of NaHCO3 results in formation of 3-iodocyclopenta[b]indoles in high yields. Under similar conditions 2-(2-cyclohexenyl)anilines give rise to cyclization products whose structure depends on the solvent and substituents in the aromatic ring and on the nitrogen atom.

Reactions of N- and C-Alkenylanilines: II. Halocyclization of 2-(2-Cycloalkenyl)anilines

Regiospecific synthesis of conjugates containing a diterpenoid fragment and a pyrazole-ring pharmacophore by 1,3-dipolar cycloaddition of diazomethane to allenoates in the presence of Et3N was demonstrated.

Synthesis of New Pyrazole–Methylmaleopimarate Conjugates

Acid-catalyzed Claisen aromatic rearrangement of ethyl N-(pent-3-en-2-yl)-N-phenylglycinate leads to the formation of ethyl N-[2-(pent-3-en-2-yl)phenyl]glycinate. The reaction of sodium salt of N-acetyl-2-(pent-3-en-2-yl)-4-methylaniline with methyl bromoacetate afforded ethyl N-acetyl-N-[4-methyl-2-(pent-3-en-2-yl)phenyl]glycinate. The hydrolysis of synthesized esters, the conversion of the obtained acids by treating with ethyl chloroformate into munchnones, and the subsequent [3+2]-cycloaddition provided methoxazoloquinoline structures.

A. A. Fatykhov

Papers

Condensation of acetylacetone with formaldehyde and thiols

Disaccharide blocks for analogs of OSW-1

Reactions of N- and C-Alkenylanilines: II. Halocyclization of 2-(2-Cycloalkenyl)anilines

Synthesis of New Pyrazole–Methylmaleopimarate Conjugates

Preparation of methano[1,3]oxazolo[3,2- a ]quinolin-2-ones from 2-(pent-3-en-2-yl)anilines