Simple and practical halogenation of arenes, alkenes and alkynes with hydrohalic acid/H2O2 (or TBHP)

Oxidative Halogenation with “Green” Oxidants: Oxygen and Hydrogen Peroxide

“…[10] Another example of the application of the HCl/H 2 O 2 system is the chlorination of cyclic and linear ketone oximes Scheme 15. Uncatalyzed oxidative chlorination requires higher reaction temperatures, and a selective reaction is difficult to achieve.…”

“…For example, the bromination of 1,4-dimethoxybenzene with HBr/H 2 O 2 (4 equiv each) in boiling methanol yielded 2,5-dibromo-1,4-dimethoxybenzene selectively. [10] Similarly, aniline (1 h) could be selectively brominated only to the tribromo derivative 66 (Scheme 21), while less-reactive substrates such as naphthalene and anthracene were selectively monobrominated. [91] When using more reactive substrates, such as para-substituted phenol, the selectivity could be controlled by the portionwise addition of H 2 …”

“…[100] A solution of HBr and H 2 O 2 in a biphasic H 2 O/CCl 4 system was used for the dibromination of various alkenes and alkynes (an example is shown in Scheme 22). [10] Cyclooctadiene (67) was transformed mainly to the 1,2-dibrominated 68, while in a one-phase reaction in MeOH an intermediate bromohydrin was formed, which transformed into 69 (Scheme 22). In contrast, a mixed dihalide 71 b was formed together with the dihalides 71 a and 71 c when HCl was added to the reaction mixture (Scheme 22).…”

Silica-supported quinolinium tribromide: a recoverable solid brominating reagent for regioselective monobromination of aromatic amines

“…Furthermore, in a similar fashion, the reactions of 1-aminonaphthalene, 2-aminobenzothiazole, 2-amino-4-methyl-benzothiazole, carbazole and 9-ethylcarbazole with SQTB were also attempted. Corresponding monobromination products were also obtained in high yield (Table 2, entries [15][16][17][18][19].…”

“…or poly(N-bromobenzene-1,3-disulfonylamide), 13 1,2-dipyridiniumditribromide-ethane, 14 ethylenebis(Nmethylimidazolium) ditribromide, 15 1-butyl-3-methylpyridinium tribromide, 16 tert-butylhydroperoxide/ HBr, 17 LiBr/(NH 4 ) 2 Ce(NO 3 ) 6 , 18 KBr/NaBO 3 ·4H 2 O, 19 2 -m e t h y l -4 -p o l y ( s t y r y l m e t h y l ) t h i a z o l i u m hydrotribromide, 20 LiBr/(diacetoxyiodo)benzene, 21 alkalimetal bromide/NaIO 4 , 22 bromodimethylsulfonium bromide, 23 HBr/H 2 O 2 , 24 1,8-diazabicyclo [5.4.0]undec-7-ene hydrobromide perbromide, 25 metal bromides/ sodium bismuthate, 26 N-octyl quinolinium tribromide 27 and pyridinium hydrobromide perbromide. 28 However, some methods still suffer from drawbacks of difficult handling, low selectivity, low yield and corrosion.…”