Sequential Formal [4+1]‐Cycloaddition, C−H Functionalization and Suzuki–Miyaura Cross‐Coupling for the Synthesis of Trisubstituted Isoxazolines

Suzuki–Miyaura cross‐coupling reaction of 3‐bromomethyl isoxazolines with arylboronic acids was suggested as final C−C bond forming step in convenient diastereoselective route to trisubstituted isoxazolines. The required bromides were readily available from nitroalkenes and sulfonium ylides through an efficient sequence of formal [4+1]‐cycloaddition and C−H functionalization of intermediate isoxazoline N‐oxides. The synthetic utility of the obtained isoxazolines was demonstrated by their conversion into valuable products such as hydroxy ketone, pyrrolidinone, etc.