Selective α-bromination of aryl carbonyl compounds: prospects and challenges

Practical and Efficient Synthesis of 2-Thio-imidazole Derivative—ZY12201: A Potent TGR5 Agonist

“…An efficient dimethylation of 1 using excess of methyl iodide afforded the desired intermediate 2 in one step with 93% yield, purified by filtration over a short path of silica gel. Subsequently, αbromination 17 of compound 2, using tetrabutyl ammonium tribromide afforded a bromo compound 3, on a multigram scale in quantitative yield. As shown in Scheme 1, 3 was directly converted into 5 using hexamethylenetetramine (HMTA), followed by treatment with hydrochloric acid.…”

Synthetic Access to Aromatic α-Haloketones

“…Even though these processes have been reviewed in the literature, a thorough and comprehensive survey is still lacking. For example, recent reviews have dealt with the α-bromination [ 28 , 29 ] and α-iodination [ 30 ] of carbonyl compounds; however, these were very specific and only involved pathways towards a very limited range of α-haloketones. In 2018, Verkariya and co-workers reviewed the synthetic access to α-iodocarbonyl compounds [ 31 ].…”

Synthetic Routes Towards the Synthesis of Geminal α‐Difunctionalized Ketones

“…Further to this, we would like to highlight to the readership that reviews focusing on the fluorination of ketones, [6] borylation of esters to access functionalised ketones, [7] methods for the synthesis of α‐acyloxy ketones, [8] α‐functionalized ketones from visible‐light promoted additions to alkenes, [9] α‐functionalized ketones from β‐keto acids, [10] selective α‐bromination of aryl carbonyl compounds, [11] application of sulfoxonium ylides to access α‐cyclopropyl and α‐dihydropyrazole ketones, [12] the trifunctionailization of alkynes to obtain functionalized ketones, [13] and the chemistry of α‐haloamides to generate new C−X bonds (X=N, O and S), [14] have recently been published and are an excellent supplement to this account.…”