Highly efficient para-selective bromination of simple aromatic substrates by means of bromine and a reusable zeolite

Synthesis, characterization, reactivity and antibacterial activity of new peroxovanadium(V) complexes anchored to soluble polymers

“…5. The thermograms of the two compounds PAV and PMAV showed the first stage of decomposition occurring between 40 and 90°C with the liberation of mole- cules of water of crystallization from the complexes with a corresponding weight loss of 12.5% (PAV) and 16.0% (PMAV). The next decomposition stage is in the temperature region of 90-250°C for PAV and 90-180°C for PMAV with a corresponding weight loss of 13.0% and 10.0%, respectively attributable to complete loss co-ordinated peroxo groups from the complexes.…”

“…Studies on synthetic peroxovanadate complexes as functional and structural models of bromoperoxidase, the enzyme involved in the biosynthesis of a variety of naturally occurring brominated products, have been immensely useful in elucidating the details of mechanism of action of the enzyme which is yet to be fully understood [1,[6][7][8][9][10][11][12]. Bromination of organic substrates, particularly aromatics, has been attracting considerable contemporary interest [13][14][15][16][17][18][19][20][21] mainly due to the commercial importance of such compounds. Since the traditional bromination methods require the use of elemental bromine and solvents which are environmentally hazardous [22], there has been a continued search for alternative benign catalytic systems which can mimic the biological bromoperoxidase in the synthesis of brominated organics.…”

Regioselective Electrophilic Aromatic Substitution Reactions over Reusable Zeolites

“…The yields and selectivities of brominated products are recorded in Table 20 [167,168]. The results in Table 20 indicated that the reaction gave high yields and para-selectivities for a range of substituted benzenes 5 of moderate activity, including alkyl and halogenobenzenes [167,168].…”

Sono-bromination of aromatic compounds based on the ultrasonic advanced oxidation processes

“…The most conventional brominating agent remains topically Br 2 , although it is hazardous and difficult in handling together with poor atom efficiency. A large panel of brominating reagents have been thus developed, including molecular bromine with or without catalysts [6][7][8][9], N-bromosuccinimide (NBS) [10-13], 1,3-dibromodimethylhydantoin (DBDMH) [13,14], N,N-dibromo-p-toluenesulfonamide (TsNBr 2 ) [15], KBrO 3 [16], or quaternary ammonium tribromide [17][18][19], etc. All of the aforementioned reagents are used in stoichiometry amount, more or less efficient, expensive, toxic, not commercially available and lead to large amounts of wastes at the end of the reaction.…”