445-03-4Relevant articles and documents
Mechanistic study of visible light-driven CdS or g-C3N4-catalyzed C–H direct trifluoromethylation of (hetero)arenes using CF3SO2Na as the trifluoromethyl source
Fu, Xianzhi,Gao, Li,Liu, Ming,Lu, Chenggang,Ma, Xiongfeng,Qin, Nanfang,Qiu, Wenzhao,Sa, Rongjian,Wang, Lele,Wei, Yingcong,Xu, Chunwang,Yuan, Rusheng,Zha, Wenying
, p. 533 - 543 (2020)
The mild and sustainable methods for C–H direct trifluoromethylation of (hetero)arenes without any base or strong oxidants are in extremely high demand. Here, we report that the photo-generated electron-hole pairs of classical semiconductors (CdS or g-C3N4) under visible light excitation are effective to drive C–H trifluoromethylation of (hetero)arenes with stable and inexpensive CF3SO2Na as the trifluoromethyl (TFM) source via radical pathway. Either CdS or g-C3N4 propagated reaction can efficiently transform CF3SO2Na to [rad]CF3 radical and further afford the desired benzotrifluoride derivatives in moderate to good yields. After visible light initiated photocatalytic process, the key elements (such as F, S and C) derived from the starting TFM source of CF3SO2Na exhibited differential chemical forms as compared to those in other oxidative reactions. The photogenerated electron was trapped by chemisorbed O2 on photocatalysts to form superoxide radical anion (O2[rad]?) which will further attack [rad]CF3 radical with the generation of inorganic product F? and CO2. This resulted in a low utilization efficiency of [rad]CF3 (3SO2Na served as the starting materials in inert atmosphere, the photoexcited electrons can be directed to reduce the nitro group to amino group rather than being trapped by O2. Meanwhile, the photogenerated holes oxidize SO2CF3? into [rad]CF3. Both the photogenerated electrons and holes were engaged in reductive and oxidative paths, respectively. The desired product, trifluoromethylated aniline, was obtained successfully via one-pot free-radical synthesis.
Transition metal-free direct C–H trifluoromethyltion of (hetero)arenes with Togni's reagent
Chen, Xiaoyu,Ding, Licheng,Li, Linlin,Li, Jingya,Zou, Dapeng,Wu, Yangjie,Wu, Yusheng
supporting information, (2019/12/30)
A new transition-metal-free direct C–H trifluoromethylation reaction of (hetero)arenes with Togni's reagent was developed. This transformation proceeded smoothly under mild conditions and exhibited good tolerance of many synthetically relevant functional groups. It provided an alternative approach for the synthesis of trifluoromethylated (hetero)arenes.
Coordinating Activation Strategy-Induced Selective C?H Trifluoromethylation of Anilines
Xu, Jun,Cheng, Ke,Shen, Chao,Bai, Renren,Xie, Yuanyuan,Zhang, Pengfei
, p. 965 - 970 (2018/02/12)
A simple protocol for the synthesis of 2-(trifluoromethyl)aniline derivatives through a coordinating activation strategy was developed. The reaction showed good reactivity and gave the target products in moderate to good yields. Pleasingly, the directing group could be recovered in excellent yield. Furthermore, this strategy allowed efficient access to the synthesis of floctafenine. A single-electron-transfer mechanism was proposed to be responsible for this trifluoromethylation reaction.
