Journal of Organic Chemistry p. 5422 - 5427 (1993)
Update date:2022-08-10
Topics:
Grissom, Janet Wisniwski
Calkins, Trevor L.
Enediynes 11 possesing a tethered olefin radical acceptor can participate in a tandem enediyne-radical cyclization to yield dihydrobenzindene derivatives 16.In the present study, the mechanism of this reaction was investigated utilizing kinetic studies to determine whether the mechanism was a radical chain, stepwise, or concerted process.Substrate concentration, 1,4-cyclohexadiene concentration, olefin geometry, and olefin electronics were varied.These experiments demonstrate that the reaction occurs under first-order kinetics over a wide variation in eithersubstrate or 1,4-CHD concentration.The reaction rate is also independent of olefin geometry and olefin electronics.The rate constants for the reactions were similar and ranged from 3.0E-4 s-1 to 6.0E-4 s-1.The data suggests that the tandem enediyne-radical cyclization proceeds through a distinct 1,4-diyl reactive intermediate such as 5 formed in the rate-determining enediyne cyclization step, followed by a radical cyclization to give 16.The tandem enediyne-radical cyclization mechanism is supported by trapping the intermediate biradical 18 in a tandem enediyne-6-exo-radical cyclization of 17 to give products 19a,b.
View MoreChangsha Huajing Powdery Material Technological Co., Ltd.
Contact:86-731-88879686
Address:Building 2, West Garden, Main Campus of Central South University, Changsha, Hunan Province, China
Qingdao Kylin Trading Co., Ltd.
Contact:0086-532-68979884/58972912/68972263/65/88171519
Address:Room 2308,A building International Trade Center No.230 Changjiang Middle Road of Qingdao Economic Development Zone,Shandong,China.
Contact:+86-571-28186845
Address:Room 1224,Eastcom Mansion,398 Wensan Road,Hangzhou,310013 China
Shanghai Yurui Biotechnology(Anyang) Pharmaceutical Co., Ltd
Contact:+86-0372-3662335 +86-0372-3661988
Address:hanling industrial park anyang
Contact:86-512-69362780,69362785
Address:No.69 Weixin Road,Weiting Town,Suzhou Industrial Park
Doi:10.1002/anie.201612071
(2017)Doi:10.1016/j.bmcl.2011.03.023
(2011)Doi:10.1021/ja980712d
(1998)Doi:10.1016/j.molliq.2020.113963
(2020)Doi:10.1002/cctc.202100245
(2021)Doi:10.1002/ejoc.200400888
(2005)