Iron-catalyzed bromination of aryl azides by N-bromosuccinimide:Efficient method for the synthesis of brominated aryl azides

An efficient and mild protocol for bromination of aryl azides with N-bromosuccinimide（NBS） under FeCl_3 catalysis in 1,2- dichloroethane was developed.It is proved to be an efficient method for obtaining brominated aryl azides.

Synthesis of 2-Oxazolines from Ethyl α-Cyanocinnamate Derivatives with Acetamide and N-Bromosuccinimide

An efficient method for the one-pot synthesis of 2-oxazolines from ethyl a-cyanocinnamate derivatives with acetamide and N-bromosuccinimide（NBS） in the presence of K3PO4 was developed. The reaction was performed smoothly and cleanly to give 2-oxazolines in good to excellent yields（up to 95%） in acetone at room temperature. Thirteen examples were investigated and the results indicated that a large range of a-cyanocinnamate derivatives could be suitable for this method. Based on the outcomes of experiment, a possible consecutive nucleophilic addition- cyclization pathway was proposed.

Facile synthesis of bromoallenes via N-bromosuccinimide/CH_3SCH_3 for the bromination of propargyl alcohols

A novel and convenient way has been developed for the preparation of bromoallenes from propargyl alcohols by the reagent combination of N-bromosuccinimide and dimethyl sulfide. Bromoallenes with high regioselectivity were obtained in a convenient method.

A facile transformation of alkynes into α-amino ketones by an N-bromosuccinimide-mediated one-pot strategy

A facile transformation of alkynes into α-amino ketones by an N-bromosuccinimide-mediated one-pot cascade strategy is described. A variety of α-amino ketones are obtained in moderate to good yields under mild conditions. To overcome the multi-step synthesis, N-bromosuccinimide is involved in multiple tasks, playing a key role in the reaction course.

One-pot synthesis of 2-aminothiazoles in PEG-400

A facile one-pot synthesis of 2-aminothiazoles has been carried in PEG-400 as a greener medium at room temperature.This method avoids the use of lachrymatric a-bromoketones as well as the volatile,toxic organic solvents.

Ab Initio Calculations on Halogen Bond Between N—Br and Electron-donating Groups

Ab initio calculations of complexes formed between N-bromosuccinimide and a series of electron-donating groups were performed at the level of MP2/Lanl2DZ^＊ to gain a deeper insight into the nature of the N--Br halogen bonding. For the small complexes, H3 C--Br… NH3 and H2 N--Br…NH3 , the primary calculation has demonstrated that the N--Br in H2 N--Br… NH3 can form a much stronger halogen-bonding complex than the C--Br. A comparison of neutral hydrogen bond complex series reveals that the electron-donating capacities of the atoms decrease in the order, N 〉 O 〉 S; 0 （ sp^3 ） 〉 0 （ sp^2 ）, which is adequate for the C--Br halogen bonding. Interaction energies, in conjunction with the geometrical parameters show that the affinitive capacity of trihalide anions X^-3 with N-bromosuccinimide are markedly lower than that of the corresponding X^- with N-bromosuccinimide, even lower than those of neutral molecules with N-bromosueeinimide. AIM analyses further eorffirmed the above results.

PHOTOBROMINATION OF SIDE-CHAIN METHYL GROUP ON METHYLNAPHTHALENES

The photobrominations of 1-methylnaphthalene (1-MN) and 2-methylnaphthalene (2-MN) were investigated by using N-bromosuccinimide (NBS) as brominating agent. The results show that under nitrogen atmosphere, side-chain methyl group on 1-MN and 2-MN can be brominated selectlvely with visible light and NBS in benzene at room temperature, and that 1-MN is photobrominated easier than 2-MN.

NBS-Promoted Sulfenylation of Sulfinates with Disulfides Leading to Unsymmetrical or Symmetrical Thiosulfonates

A highly practical method to access unsymmetrical and symmetrical thiosulfonates in moderate to excellent yields has been developed through NBS-promoted sulfenylation of sulfinates with disulfides. The present process enables the use of two RS in RSSR and shows broad functional group tolerance, which represents an atom-economical and practical procedure for the synthesis of thiosulfonates. A plausible mechanism for the role of NBS as a promoter for the cleavage of disulfides generating N-（organothio）succinimide that then undergos facile sulenylation with sulfinates is proposed.

Dual Stereocontrol for Enantioselective Hydrogenation of Dihydroisoquinolines Induced by Tuning the Amount of N-Brornosuccinirnide

An efficient dual stereocontrot in iridium-catalyzed hydrogenation of 1-substituted 3,4-dihydroisoquinolines was realized by tuning the amount of N-bromosuccinimide using chiral ligand of single configuration, providing both enantiomers of 1-substituted 1,2,3,4-tetrahydroisoquinolines with up to 89% ee （S） and 98% ee＊（R）, respectively. Dual activation role of N-bromosuccinimide is proposed to be responsible for the reversal of enantioselectivity under two hydrogenation conditions.

Utilization of bromine azide to access vicinal-azidobromides from arylidene malononitrile

An efficient and facile approach for tetrachlorosilane as an in situ mediated transformation via a one-pot, synthesis of vicinal bromoazides through the generation of BrN3 from azidochlorosilane and N-bromosuccinimide in acetonitrile as solvent at ambient temperature is achieved. This catalytic process represents a highly regioselective and high yielding method for the synthesis of 1,2- bromoazides. Thiamine pyrophosphate （TPP） riboswitches regulate essential genes in bacteria by changing conformation upon binding intracellular TPP. Molecular docking studies are conducted to understand the orientation and the interaction of each synthesized molecules with TPP riboswitches, 2016 Chinese Chemical Society and Institute of Materia Medica, Chinese Academv of Medical Sciences.

Selective α-Bromination of β-Keto Esters in Reusable PEG-400 under Mild and Catalyst-free Conditions

An efficient bromination protocol for the synthesis of α-bromo-β-keto esters has been developed. In PEG-400 （poly（ethylene glycol-400））, a variety of β-keto esters were treated with NBS （N-bromosuccinimide） at room temperature to selectively afford the corresponding α-monobromination products in excellent yields. It is noteworthy that the reaction was conducted under mild, environmentally benign and catalyst-free conditions.