Journal of Organic Chemistry p. 8571 - 8582 (2015)
Update date:2022-09-26
Topics:
Kennedy, Nicole
Lu, Gang
Liu, Peng
Cohen, Theodore
One of the most widely used methods of preparation of organolithium compounds is by the reductive lithiation of alkyl phenyl thioethers or, usually less conveniently, alkyl halides with either aromatic radical-anions of lithium or lithium metal in the presence of an aromatic electron-transfer catalyst. Here we present results showing that lithium dispersion can achieve reductive lithiation in the absence of the electron-transfer agent. This procedure is more efficient, and surprisingly, the order of reactivity of substrates is reversed depending on whether the electron-transfer agent is present or absent. For example, in the presence of a preformed radical-anion, tert-butyl phenyl sulfide cleaves significantly faster than methyl phenyl sulfide, whereas in the absence of the radical-anion, it is just the opposite. Density functional theory calculations reveal that the exothermicity of the cleavage of the C-S bond in alkyl phenyl thioethers on the lithium surface is dependent on the size of the alkyl group, the smaller the alkyl group the greater the exothermicity. The increased reactivity is attributed to the smaller steric repulsion between the alkyl group and the lithium surface. The methodology includes, but may not be limited to, the lithium dispersion reductive lithiation of phenyl thioethers, alkyl chlorides, acrolein diethyl acetal, and isochroman.
View MoreChengdu Biopurify Phytochemicals Ltd.
website:http://www.phytopurify.com
Contact:+86-28-82633397
Address:2F,No.11 Building,No.388 Rongtaidadao CNSTP,Wenjiang Zone,Chengdu,Sichuan, China
Contact:+86-535-8888888
Address:No.161 Haishi Rd.
Chongqing Yawei Fine Chemical Co.,Ltd
Contact:0086-23-62849407
Address:Ziyou village, Nanquan town, Banan district, Chongqing China
Lanzhou huibang biological chemical technology Co., LTD
Contact:0931-7843964
Address:NO.2011,Yannan Road,Chengguan,
Jiangxi Lixin Pharmaceutical Co.,Ltd.
Contact:0798-8337222; 18979813215
Address:Jiangxi City, Jindezheng Province
Doi:10.1021/ja00061a005
(1993)Doi:10.1021/jo01020a003
(1965)Doi:10.1055/s-2001-11408
(2001)Doi:10.1002/cber.19711040823
(1971)Doi:10.1002/1099-0690(200103)2001:5<875::AID-EJOC875>3.0.CO;2-R
(2001)Doi:10.1039/j39710003100
(1971)