NUCLEOPHILIC FLUORINATION OF AN ALKYL BROMIDE UNDER CROWN ETHER CATALYSIS AND A BULKING DIOL OR HEXAFLUORINATED ALCOHOL
Fluorination, Catalysis, Medicinal Chemistry
The Nucleophilic Fluorination reactions have gained notoriety over the years, this the due to great applications that Organic Fluorine Chemistry presents. Among these, we can mention positron emission tomografy, better known as (oncological PET), where F-18-FDG, a glucose analogue that has the ability to map benign and maglignant cells, is injected into the patient´s blood. In pharmacology, in 2014, it was estimated that there are more than 200 fluorinated drugs on the marked and, currently, new fluorinated drugs continue to emerge, at 15 to 20% per year, as they have several advantegeous biological properties derived from the insertion of fluorine element. However, for nucleophilic fluorination reactions , toxic reagents are still used and often have low solubility in organic solvents, in addition to the competition between SN2 e E2. However, to resolve these issues regarding solubility and seletivity, crown ethers are used together with alcoohols that will assist in the solubilization stage and activation of the SN2 reaction. In this work proposal, we wish to investigate the use of primary bromides for fluorination , using a phase transfer catalyst such crown ethers together with a bulkyl alcohol or fluorinated alcohol , to obtain primary fluorides selectively and with good yields. The result using 3 mmol of TBOHF6 stands out, where 80% conversion of the fluorinated product was achieved, demonstrating that the use of TBOHF6 is more favorable than BDMB.