A Microwave-Promoted/Assisted Method for Rapid Preparation of Biaryl Seven-membered Lactones

Background: Biaryl seven-membered lactones (BSLs), the target compounds are a class of bioactive compounds with anti-arrhythmic activity, which also serve as a starting material or structural units for chemical synthesis. Objective: To report a simple and efficient procedure for the synthesis of biaryl seven-membered lactones. Method: Under microwave, the umpolung reaction was promoted by N-heterocyclic carbenes under oxygen, with anhydrous potassium carbonate as base and with 1,4,7,10,13,16-Hexanoxacyclooctadecane (18-crown-6) as a phase-transfer catalyst. Results: The practical protocol was found to be compatible with different structurally diverse substrates and with moderate to excellent yields. Conclusion: This synthesis method has the advantage of high efficacy and novelty, short reaction time, operation simplicity, mild condition and high yields, providing a useful and atom-economic approach to the synthesis of BSLs.