Divergent Single-Oxygen Transmutation of Furans.

Despite the prevalence of furans in organic chemistry, their direct conversion into diverse heterocycles via oxygen transmutation remains a formidable challenge. This limitation is primarily attributed to the robust endocyclic C-O bonds, its aromaticity, and the lack of strategies to activate inert oxygen atoms. In this study, we report a lithium-mediated strategy that enables the divergent transmutation of furan oxygen atoms. By employing a mechanochemical ball-milling protocol, we achieve this transformation under mild and operationally simple conditions, significantly enhancing the efficiency compared to conventional solution-phase methods. This approach enables the precise replacement of oxygen with diverse elements-including silicon, carbon, selenium, phosphorus, germanium, and titanium-via deoxygenatively dilithiated intermediates that react in situ with various electrophiles, thereby providing direct access to a library of valuable heterocycles. This work highlights a versatile platform for molecular diversification with endocyclic transmutation, demonstrating that mechanochemistry can serve as an operationally efficient and time-saving strategy for complex heterocycle synthesis.