Palladium-Catalyzed Carbonylative Synthesis of 2,3-Disubstituted Chromones was written by Shen, Chaoren;Li, Wanfang;Yin, Hongfei;Spannenberg, Anke;Skrydstrup, Troels;Wu, Xiao-Feng. And the article was included in Advanced Synthesis & Catalysis in 2016.Computed Properties of C7H6BrF This article mentions the following:
An unexpected palladium-catalyzed carbonylative synthesis of 2,3-disubstituted chromones I (R = 7-Me, 6-Cl, 6-CHF2, etc.; R1 = 2-Me, 4-MeO, 2,4-Cl2, etc.; R2 = 4-ClC6H4, 4-MeC6H4, CH2C6H5, etc.) has been developed. Starting from 2-bromofluorobenzenes R42-BrFC6H3 (R4 = 4-Me, 5-Me, 6-F, etc.) and ketones R2(O)CCH2C6H4R1, the corresponding chromones I were produced in good yields. By control experiments, this transformation was found to proceed through a sequential carbonylation/Claisen-Hasse rearrangement/intramol. nucleophilic aromatic substitution approach (SNAr). More specifically, the reaction sequence started with a palladium-catalyzed carbonylation of the ketone with o-bromofluorobenzene to give the vinyl benzoates, which subsequently transformed into 1,3-diketones via a Claisen-Hasse rearrangement. The final products were produced after an intramol. SNAr reaction of the in situ formed 1,3-diketone. In the experiment, the researchers used many compounds, for example, 3-Bromo-4-fluorotoluene (cas: 452-62-0Computed Properties of C7H6BrF).
3-Bromo-4-fluorotoluene (cas: 452-62-0) belongs to organobromine compounds. Bromine is more electronegative than carbon (2.9 vs 2.5). Consequently, the carbon in a carbon–bromine bond is electrophilic, i.e. alkyl bromides are alkylating agents. Commercially available organobromine pharmaceuticals include the vasodilator nicergoline, the sedative brotizolam, the anticancer agent pipobroman, and the antiseptic merbromin. Computed Properties of C7H6BrF
Referemce:
Bromide – Wikipedia,
bromide – Wiktionary