标题：Selective endoperoxide formation by heterogeneous TiO2 photocatalysis with dioxygen
作者：Qiao, Xiaofeng; Biswas, Subharanjan; Wu, Wenli; Zhu, Feng; Tung, Chen-Ho; Wang, Yifeng
作者机构：[Qiao, Xiaofeng; Biswas, Subharanjan; Wu, Wenli; Zhu, Feng; Tung, Chen-Ho; Wang, Yifeng] Shandong Univ, Sch Chem & Chem Engn, Key Lab Colloid & Inteif 更多
通讯作者地址：[Wang, YF]Shandong Univ, Sch Chem & Chem Engn, Key Lab Colloid & Inteiface Sci, Minist Educ, Jinan 250100, Shandong, Peoples R China.
关键词：Heterogeneous photocatalysis; Oxygenation; Selective oxidation; Solar; synthesis; Cascade reaction
摘要：We report the selective formation of endoperoxides by aerobic TiO2 photocatalysis through the cyclic addition of dioxygen and a non-conjugated diene, the first heterogeneous catalytic system for endoperoxide synthesis. This green protocol does not require any additive and the photocatalyst is abundant and recyclable, providing a yield up to 64% and >20:1 diastereoselectivity. Mechanistic investigations were carried out by using product analysis, kinetic studies, O-18 labelling experiments, electron-spin resonance and a set of quenching experiments. Superoxide (but not singlet oxygen, triplet oxygen or peroxide) is directly involved in the reaction cascade to form the endoperoxide product The new findings may be helpful for future for designing eco-friendly and energy sustainable strategies for selective oxygenation reactions using semiconductors, O-2 and sunlight. (C) 2018 Elsevier Ltd. All rights reserved.