A one-step catalytic oxidant-free synthesis of unsaturated ketones from 1,2-disubstituted cyclopropanols is reported. Previously for this transformation, only two- and three-step protocols have been developed. The reaction proceeds under irradiation with visible light in the presence of catalytic amounts of both an acridinium photocatalyst and a cobaloxime complex. 2-Aryl-substituted cyclopropanols react giving α,β-unsaturated ketones, while dehydrogenative ring opening of 2-alkyl-substituted substrates affords mixtures of α,β- and β,γ-enones. The reaction starts with one-electron oxidation of a cyclopropanol to cyclopropyloxy radical, presumably, by the photoexcited acridinium catalyst. We also found that Co(dmgBF₂)₂(MeCN)₂ complex under an air atmosphere and irradiation with blue LEDs or upon heating can serve as a hydroxycyclopropane oxidant.

据报道，由1,2-二取代的环丙醇可一步催化无氧化剂合成不饱和酮。以前，此转换仅开发了两步和三步协议。该反应在催化量的photo啶光催化剂和钴肟肟络合物的存在下在可见光的照射下进行。2-芳基取代的环丙醇反应生成α，β-不饱和酮，而2-烷基取代的底物的脱氢开环提供α，β-和β，γ-烯酮的混合物。该反应开始于环丙醇被光激发的to啶催化剂单电子氧化为环丙氧基。我们还发现Co（dmgBF ₂）₂（MeCN）₂ 在空气气氛下用蓝色LED照射或加热时生成的配合物可用作羟基环丙烷氧化剂。