6942-99-0Relevant articles and documents
Aromatic Halogenation Using N-Halosuccinimide and PhSSiMe3 or PhSSPh
Hirose, Yuuka,Yamazaki, Mirai,Nogata, Misa,Nakamura, Akira,Maegawa, Tomohiro
, p. 7405 - 7410 (2019/06/14)
We developed a mild aromatic halogenation reaction using a combination of N-halosuccinimide and PhSSiMe3 or PhSSPh. Less reactive aromatic compounds, such as methyl 4-methoxybenzoate, were brominated with PhSSiMe3 or PhSSPh and N-bromosuccinimide in high yields. No reaction was observed in the absence of PhSSiMe3 or PhSSPh. This method is also applicable to chlorination reactions using N-chlorosuccinimide and PhSSPh.
Aromatic substitution in ball mills: Formation of aryl chlorides and bromides using potassium peroxomonosulfate and NaX
Schmidt, Robert,Stolle, Achim,Ondruschka, Bernd
, p. 1673 - 1679 (2013/02/22)
Aryl chlorides and bromides are formed from arenes in a ball mill using KHSO5 and NaX (X = Cl, Br) as oxidant and halogen source, respectively. Investigation of the reaction parameters identified operating frequency, milling time, and the number of milling balls as the main influencing variables, as these determine the amount of energy provided to the reaction system. Assessment of liquid-assisted grinding conditions revealed, that the addition of solvents has no advantageous effect in this special case. Preferably activated arenes are halogenated, whereby bromination afforded higher product yields than chlorination. Most often reactions are regio- and chemoselective, since p-substitution was preferred and concurring side-chain oxidation of alkylated arenes by KHSO5 was not observed. The Royal Society of Chemistry.
Increasing the selectivity of bromination of aromatic compounds using Br2/SiO2
Ghiaci,Asghari
, p. 1151 - 1152 (2007/10/03)
Br2/SiO2 possessed considerable practical advantages over traditional reagents for the bromination of aromatic hydrocarbons, e.g., toluene, o-, m-, and p-xylene, anthracene and phenol. In the presence of SiO2, toluene reacted with bromine instantly. Compounds containing electron-donating substituents showed mainly bromination on the rings. The behavior of o-, m-, and p-xylene showed predominant substitution on the rings. The bromination of phenol to p-bromophenol showed good yield at 81%. Naphthalene was monobrominated to 1-bromonaphthalene with a yield of 84% in 2 has the potential to alter reaction selectivity. It may be able to switch a mechanism from radical to polar, or to influence the regioselectivity of the products formed. In the absence of SiO2, selectivity was lost and a mixture of products by substitution of bromine atom on the ring and on the side chain without any preferability was obtained. The nature of silica gel was important for the success of the reaction. Optimal results were obtained with silica gel dried at 250°C for 1 hr.