Photo[2+2]cycloaddition of olefins is a sought-after tool for making cyclobutanes,which are the building blocks for a wide range of biologically active molecules and natural products.However,the formation of cyclobuta...Photo[2+2]cycloaddition of olefins is a sought-after tool for making cyclobutanes,which are the building blocks for a wide range of biologically active molecules and natural products.However,the formation of cyclobutane derivatives from aryl terminal olefins is problematic due to their high redox potential,and high energy in the excited state,making visible-light-absorbing photocatalyst difficult to realize either electron or energy transfer to olefins during the photocyclic addition process.Herein,we report,for the first time,the aggregationinduced photo[2+2]cycloaddition of two olefins by visible-light catalysis in homogeneous solution.An array of control experiments and spectroscopic analyses reveal that the terminal olefins tend to aggregate to form excimers/exciplexes,which possess much lower energy than their monomeric forms,and enables triplet energy transfer from excited Ir(ppy)3*to supramolecular self-assembly feasible,leading to homo and cross[2+2]photodimerization of the olefins to fabricate cyclobutanes at ambient conditions in good to excellent yields.展开更多
基金This work was supported financially by the Ministry of Science and Technology of China(2017YFA0206903)the National Natural Science Foundation of China(21861132004)+1 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB17000000)the Key Research Program of Frontier Sciences of the Chinese Academy of Sciences(QYZDY-SSW-JSC029),and K.C.Wong Education Foundation.
文摘Photo[2+2]cycloaddition of olefins is a sought-after tool for making cyclobutanes,which are the building blocks for a wide range of biologically active molecules and natural products.However,the formation of cyclobutane derivatives from aryl terminal olefins is problematic due to their high redox potential,and high energy in the excited state,making visible-light-absorbing photocatalyst difficult to realize either electron or energy transfer to olefins during the photocyclic addition process.Herein,we report,for the first time,the aggregationinduced photo[2+2]cycloaddition of two olefins by visible-light catalysis in homogeneous solution.An array of control experiments and spectroscopic analyses reveal that the terminal olefins tend to aggregate to form excimers/exciplexes,which possess much lower energy than their monomeric forms,and enables triplet energy transfer from excited Ir(ppy)3*to supramolecular self-assembly feasible,leading to homo and cross[2+2]photodimerization of the olefins to fabricate cyclobutanes at ambient conditions in good to excellent yields.
