Two-electron reduction of[N_(2)NBn]Ti^(Ⅳ)Cl2(3)gave a highly reactive[N_(2)N]Ti^(Ⅱ)species,which underwent C—O bond activation of THF(tetrahydrofuran)to generate[N2NBn]Ti^(Ⅳ)[O(CH2)4](4)through oxidative addition....Two-electron reduction of[N_(2)NBn]Ti^(Ⅳ)Cl2(3)gave a highly reactive[N_(2)N]Ti^(Ⅱ)species,which underwent C—O bond activation of THF(tetrahydrofuran)to generate[N2NBn]Ti^(Ⅳ)[O(CH2)4](4)through oxidative addition.The resulted Ti^(Ⅳ)-Csp^(3)bond in oxametallacyclo-hexane was tantamount to the elaborately-designed Ti-alkyl complexes,competent to activate intramolecular Csp^(2)-H bond,forming ortho-cyclometalated complex[N_(2)NCH_(2)C_(6)H_(4)]Ti^(Ⅳ)(O^(n)Bu)(5).Key intermediates were isolated and fully characterized by X-ray crystal-lography.Mechanistic studies revealed that the oxidative addition of C-O bond took place at Ti^(Ⅱ)-center via a radical intermediate,while a Csp^(2)-H bond activation proceeded byσ-bond metathesis with a kitelike four-centered Ti^(Ⅳ)-transition state.展开更多
基金support from the National Natural Science Foundation of China(Nos.21988101,21881220232,21811530004,21761132027,22071029,22201044,U19B6002)Key-Area Research and Development Program of Guangdong Province(2020B010188001).
文摘Two-electron reduction of[N_(2)NBn]Ti^(Ⅳ)Cl2(3)gave a highly reactive[N_(2)N]Ti^(Ⅱ)species,which underwent C—O bond activation of THF(tetrahydrofuran)to generate[N2NBn]Ti^(Ⅳ)[O(CH2)4](4)through oxidative addition.The resulted Ti^(Ⅳ)-Csp^(3)bond in oxametallacyclo-hexane was tantamount to the elaborately-designed Ti-alkyl complexes,competent to activate intramolecular Csp^(2)-H bond,forming ortho-cyclometalated complex[N_(2)NCH_(2)C_(6)H_(4)]Ti^(Ⅳ)(O^(n)Bu)(5).Key intermediates were isolated and fully characterized by X-ray crystal-lography.Mechanistic studies revealed that the oxidative addition of C-O bond took place at Ti^(Ⅱ)-center via a radical intermediate,while a Csp^(2)-H bond activation proceeded byσ-bond metathesis with a kitelike four-centered Ti^(Ⅳ)-transition state.
