22002-45-5Relevant articles and documents
MECHANISM OF ISOMERISATION OF ortho OR para BROMO PHENOLS IN SUPERACIDS
Jacquesy, Jean-Claude,Jouannetaud,Marie-Paule
, p. 1673 - 1676 (1982)
In superacids ortho or para bromo phenols are isomerised into the meta bromo isomers.In SbF5-HF, the process is intramolecular and proceeds by a 1,2-Br shift.In CF3SO3H, the mechanism involves loss of bromine, followed by meta bromination.
Bridged nitrogen-containing heterocyclic metallocene compound as well as preparation method and application thereof
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Paragraph 0100; 0121, (2021/10/16)
The invention provides a bridged nitrogen-containing heterocyclic metallocene compound, which has the structure shown in the formula (I). In-flight R1 A substituted or unsubstituted C1 - C30 alkyl group, a substituted or unsubstituted C3 - C30 cycloalkyl group, a substituted or unsubstituted C6 - C30 aromatic group, a substituted or unsubstituted C6 - C30 aromatic heterocyclic group. R2 AND R3 A C1 - C10 alkyl group or a phenyl group is each independently selected. R4 A substituted or unsubstituted C1 - C10 alkyl, substituted or unsubstituted C6 - C20 aromatic group. X Is a halogen, a substituted or unsubstituted alkyl group. M Is 4th-valent transition metal titanium. Zircon or hafnium. Compared with the prior art, the metallocene compound provided by the invention is convenient to modify, high in catalytic activity and good in temperature resistance, can maintain high catalytic activity under high-temperature conditions, can catalyze copolymerization of ethylene and α - olefin, and can obtain a polymer product with high molecular weight and high comonomer insertion rate.
Eco-Friendly Methodology for the Formation of Aromatic Carbon–Heteroatom Bonds by Using Green Ionic Liquids
Richards, Kenza,Petit, Eddy,Legrand, Yves-Marie,Grison, Claude
supporting information, p. 809 - 814 (2020/11/30)
A new sustainable method is reported for the formation of aromatic carbon–heteroatom bonds under solvent-free and mild conditions (no co-oxidant, no strong acid and no toxic reagents) by using a new type of green ionic liquid. The bromination of methoxy arenes was chosen as a model reaction. The reaction methodology is based on only using natural sodium bromine, which is transformed into an electrophilic brominating reagent within an ionic liquid, easily prepared from the melted salt FeCl3 hexahydrate. Bromination reactions with this in-situ-generated reagent gave good yields and excellent regioselectivity under simple and environmentally friendly conditions. To understand the unusual bromine polarity reversal of sodium bromine without any strong oxidant, the molecular structure of the reaction medium was characterised by Raman and direct infusion electrospray ionisation mass spectroscopy (ESI-MS). An extensive computational investigation using density functional theory methods was performed to describe a mechanism that suggests indirect oxidation of Br? through new iron adducts. The versatility of the methodology was successively applied to nitration and thiocyanation of methoxy arenes using KNO3 and KSCN in melted hexahydrated FeCl3.
Atom-economical brominations with tribromide complexes in the presence of oxidants
Yubata, Kotaro,Matsubara, Hiroshi
supporting information, p. 1001 - 1004 (2019/03/13)
Bromination is an important transformation in organic synthesis, and novel efficient bromination techniques are still required. Herein, we demonstrate atom-economical brominations using (DMI)2HBr3, a novel tribromide complex, with oxidants such as DMSO and Oxone. Using this system, olefinic and aromatic brominations, as well as selective α-monobrominations of ketones proceeded well to afford the desired bromides in good yields. Importantly, in these reactions all of the bromine atoms in this complex are used to brominate.
