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Construction of Cyclobutanes by Multicomponent Cascade Reactions in Homogeneous Solution through Visible-Light Catalysis |
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| Authors: | Dr Tao Lei Chao Zhou Xiang-Zhu Wei Dr Bing Yang Prof Dr Bin Chen Prof Dr Chen-Ho Tung Prof Dr Li-Zhu Wu |
| Institution: | 1. Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, The Chinese Academy of Sciences, Beijing, 100190 P. R. China
School of Future Technology, University of Chinese Academy of Sciences, Beijing, 100049 P. R. China These authors contributed equally to this work.;2. Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, The Chinese Academy of Sciences, Beijing, 100190 P. R. China School of Future Technology, University of Chinese Academy of Sciences, Beijing, 100049 P. R. China;3. Key Laboratory of Photochemical Conversion and Optoelectronic Materials, Technical Institute of Physics and Chemistry, The Chinese Academy of Sciences, Beijing, 100190 P. R. China |
| Abstract: | 2+2] Photocycloaddition of two olefins is a general method to assemble the core scaffold, cyclobutane, found in numerous bioactive molecules. A new approach to synthesize cyclobutanes through multicomponent cascade reactions by merging aldol reaction and Witting reaction with visible-light-induced 2+2] cycloaddition is reported. An array of cyclobutanes with high selectivity has been achieved from commercially available aldehydes, ketones (or phosphorus ylide), and olefins with visible-light irradiation of a catalytic amount of (fac-tris(2-phenylpyridinato-C2,N)iridium) (Ir(ppy)3]) at room temperature. Control experiments and spectroscopic studies revealed that the triplet–triplet energy transfer from the excited Ir(ppy)3]* to enones, generated in situ from aldehyde and ketone or aldehyde and phosphorus ylide, is responsible for these simple and efficient muticomponent transformations. |
| Keywords: | aldol reaction cyclobutane multicomponent cascade reactions [2+2] photocycloaddition Witting reactions |