OrganobismuthThe main synthesis methods of compounds are: organometallic routes, routes (onium routes), alkali metal bismuth salt routes, electrochemical arylation, reaction between organic halides and bismuth metal, disproportionation reaction, oxidation Addition routes, displacement reactions, ligand complexation, etc. Here we only introduce several newly synthesized organobismuth compounds.
OrganobismuthCompounds can undergo coupling reactions with many reagents under transition metal catalysis. Catalytic coupling reaction between organobismuth dialkoxy compounds and trifluoromethanesulfonic acid compounds (R2OTf, R=vinyloraryl). When the aryl group or vinyl group of R2OTf contains an electron-withdrawing substituent, the organic bismuth compound can quickly undergo a cross-linking coupling reaction with it, and the maximum yield of the target product can reach 99%. However, when the aryl or vinyl groups contain electron-donating substituents, the coupling reaction cannot occur.
In the past decade or so, organobismuth reagents have been proven to be better arylation reagents due to their mild reaction conditions and ability to Tolerant to the influence of other functional groups. Among them, triarylbismuth(Ⅴ) derivatives are efficient reagents for nucleophilic aryl substitution under the coordination coupling mechanism. These reactions selectively occur at the ipso position. Typical arylation reactions include C2, N2 and O2 arylation reactions.
Organic Bismuthhas been used in fields such as medicine, catalysis, cosmetics and electronic technology. Many organic bismuth compounds can treat gastric ulcer, duodenal ulcer, gastritis, dyspepsia, colon and peptic ulcer disease, toxic diarrhea, dermatitis, hemorrhoids, syphilis and other diseases.
At present, the widely used bismuth agents are mainly colloidal bismuth subcitrate (De2Nol○ R) and alkali for the treatment of gastric and duodenal ulcers. Formula bismuth salicylate (Pepto2 Bismol○ R), ranitidine bismuth citrate, etc., which combine anti-secretion, cell protection and anti-Helicobacter pylori effects. Although bismuth can prevent the growth of Helicobacter pylori, the microorganism that causes gastric disease, its mechanism of action is unclear.
In addition, it is still not possible to accurately know the value of The precise structure of the protective isolation layer formed by organic bismuthcompounds. Studies have shown that colloidal bismuth subcitrate can form at least 12 types of polymers composed of double Bi core structural units [Bi(cit)2Bi]2- under different crystallization conditions.
