Several processes of NBs free-based halogen reactions are summarized.

related topics . NBS brominated
reagements
and brominated reactions halide
compounds
are the starting material for many synthetic reactions, and too many of these compounds are easily developed from parent hydrocarbons by replacing them with freelances using halogen monosyl or other halides, most commonly acrylic halide. In practice, there are many halogenated reagents such as N-bromideamide, N. brominated statins, l, 21 dibrominated il, 2,3,41 tetrachloroethylene, N-1 bromide diamide (
NBS
) and other halogenated reactions that can occur at the acrylic base, of which N-bromide diamide (NBs) is one of the most commonly used reagents. The reaction using this reagent is called the wolll one zied "reaction." However, the course of many students' reaction to this reaction is still unclear. The reason for this is, on the one hand, that some teaching materials present different courses for this reaction, so that students have no dependence. On the other hand, many teaching materials because of space constraints can not tell the course thoroughly, leading to students have doubts. This paper describes the course of several NBs bromide reactions and does some rough dialysis to help readers better understand NBs bromide reactions.1944, B100m6eld proposed a reaction course based on the butylamide free-chain deliveryA reaction course based on bromine free-chain deliveryIncremona also proposed a process of reaction based on bromine free-chain delivery in 1970, which differs from the process of GOLD6ngerit can be argued that the
NBS
bromine reaction is based on the process of bromine free-chain delivery. However, NBs in the response, only a continuous and stable provision of low concentrations of bromide molecular bromine, not directly to provide bromine free agents. The entity of the reaction is molecular bromide. Therefore, the G0ld ChuIlger journey is more reasonable. One might ask why molecular bromine does not react with double bonds with ions or free fundamentals, since the entity of the reaction in the NBs reaction is molecular bromide? This is because, in the course of this reaction, both NBs and molecular bromine have shown similar selectivity", since the concentration of molecular bromine is too low, in terms of bi-bond bromine, only one atom in the attacking bromine molecule is connected to the substitum, whether it is a pro-electric addition or a free-based addition, and the other bromine atom must come from another molecule or ion containing bromine.
.