Catalytic reductive ring opening of epoxides enabled by zirconocene and photoredox catalysis

•Unprecedented zirconocene catalysis in reductive ring opening of epoxides•Broad reactivity across diverse substrates, including natural products•Reverse regioselectivity compared with the well-established methods titanocene•Changing metal center metallocene alters reversibility Epoxides are key structural motifs commonly found products and medicinal agrochemical agents as well various intermediates. Although epoxides generally act an electrophile, furnishes a nucleophilic carbon radical to undergo variety functionalizations. Titanocene(III) has been recognized unique for by synthetic chemists over past 30 years. Despite tremendous advances titanocene-mediated opening, counterpart is currently unknown. Intrigued comparatively oxophilic nature zirconium altering reaction profile, we investigated zirconocene-mediated opening. Contrasting renders our protocol complementary titanocene. We believe that this method will become strategically important transformation chemical synthesis, leading revisiting potential chemistry. The powerful convert readily accessible into array valuable alcohols, pharmaceuticals, agrochemicals, functional polymers. significant progress made, established were limited titanocene-catalyzed reactions. Herein, report unprecedented zirconocene-catalyzed epoxide enabled photoredox catalysis. Compared conventional ring-opening methods, present exhibited reverse afford more substituted alcohols via putative less-stable radicals. This remarkably mild smoothly cleaves C–O bonds molecules groups, products. finding changing influences energy profile advance provides new perspective chemistry group IV metals. IntroductionEpoxide common motif bioactive compounds, naturally occurring feedstocks, Due inherent strain, behave excellent electrophiles. 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Benzyl (1A), p-methoxybenzyl (1B), (1C) oxiranes accommodated corresponding secondary 2A–2C regioselectivity. esters (1D–1F), silyl ethers (1G 1H), chloride (1I), rings (1J–1O) tolerated. Protected L-prolinol (1P–1R), sulfonamide (1S), suitable substrates. di- epoxides. converted 1,1-disubstituted 1T 1U retained whereas 1V afforded 41% 2V 3V 4V, suggesting primary ring. Spiro (1W–1Z) uniformly desired 2W–2Z, incorporation bulky adamantane (1AA) considerably 1,2-Disubstituted sizes tolerated (1AB–1AF) comparable results those previously reactions.28Lin