4258-28-0Relevant academic research and scientific papers
Palladium-Catalyzed Hydroxylation of Aryl Halides with Boric Acid
Song, Zhi-Qiang,Wang, Dong-Hui
, p. 8470 - 8474 (2020)
Boric acid, B(OH)3, is proved to be an efficient hydroxide reagent in converting (hetero)aryl halides to the corresponding phenols with a Pd catalyst under mild conditions. Various phenol products were obtained in good to excellent yields. This transformation tolerates a broad range of functional groups and molecules, including base-sensitive substituents and complicated pharmaceutical (hetero)aryl halide molecules.
Identification of position isomers by energy-resolved mass spectrometry
Menachery, Sunil Paul M.,Laprévote, Olivier,Nguyen, Thao P.,Aravind, Usha K.,Gopinathan, Pramod,Aravindakumar, Charuvila T.
, p. 944 - 950 (2015)
This study reports an energy-resolved mass spectrometric (ERMS) strategy for the characterization of position isomers derived from the reaction of hydroxyl radicals (-OH) with diphenhydramine (DPH) that are usually hard to differentiate by other methods. The isomer analogues formed by ?OH attack on the side chain of DPH are identified with the help of a specific fragment ion peak (m/z 88) in the collision-induced dissociation (CID) spectrum of the protonated molecule. In the negative ion mode, the breakdown curves of the deprotonated molecules show an order of stability (supported by density functional theory (DFT) calculations) ortho > meta > para of the positional isomers formed by the hydroxylation of the aromatic ring. The gas phase stability of the deprotonated molecules [M - H]- towards the benzylic cleavage depends mainly on the formation of intramolecular hydrogen bonds and of the mesomeric effect of the phenol hydroxyl. The [M - H]- molecules of ortho and meta isomers result a peak at m/z 183 with notably different intensities because of the presence/absence of an intramolecular hydrogen bonding between the OH group and C9 protons. The ERMS approach discussed in this report might be an effective replacement for the conventional methods that requires very costly and time-consuming separation/purification methods along with the use of multi-spectroscopic methods.
