Journal of Organic Chemistry p. 9727 - 9736 (2020)
Update date:2022-08-04
Topics:
Baek, Jihye
Je, Eun-Kyung
Kim, Jina
Qi, Ai
Ahn, Kwang-Hyun
Kim, Yongho
The controversial single-electron-transfer process, frequently proposed in many 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ)-mediated reactions, was investigated experimentally and theoretically using the oxidative cyclization of aroylhydrazone with DDQ. DDQ-mediated oxadiazole formation involves several processes, including cyclization to form an oxadiazole ring and N-H bond cleavage, either by proton, hydride, or hydrogen atom transfer. The detailed mechanistic study using the M06-2X density functional theory, and the 6-31+G(d,p) basis set, suggests that the pathways involving radical ion pair (RIP) intermediates, which resulted from single-electron transfer (SET), were found to be energetically nearly identical to the pathway without the SET. The substituent-dependent reactivity of oxadiazole formation was consistent with the free energy profiles of both pathways, with or without the SET. This result indicates that in addition to the electron-transfer pathway, the nucleophilic addition/elimination pathway for DDQ should be considered as a possible mechanism of the oxidative transformation reaction using DDQ.
View MoreHunan Shineway Enterprise Co., Ltd.
Contact:+86-731-86303875
Address:118, Huanghua International Airport Road, Huanghua Town, Changsha, Hunan 410137, China
website:http://www.sagechem.com
Contact:+86-571-86818502
Address:Room C1301, New Youth Plaza, 8 Jia Shan Road, Hangzhou, China
Nanjing Fubang Chemical Co.,Ltd
Contact:+86-25-83179199
Address:5F,Tianzheng international plaza,No399 Zhongyang Road ,Nanjing China
Chongqing Rong&Quan Pharmaceutical Technology Co. , Ltd.
Contact:86-023-65268721
Address:No. 7, Manshanhong Village, Pingdingshan, Shapingba District, Chongqing Province, China
TAIXING BEST NEW MATERIALS CO., LTD
Contact:0523-87998158;
Address:No.18 Zhonggang Road,Taixing City ,Jiangsu , China
Doi:10.1016/S0968-0896(02)00472-8
(2003)Doi:10.1016/0040-4039(94)80102-9
(1994)Doi:10.1002/chem.201502481
(2015)Doi:10.1016/S0022-328X(00)87650-0
(1982)Doi:10.1002/anie.201904899
(2019)Doi:10.1002/jlcr.828
(2004)