Journal of the Chemical Society. Perkin transactions II p. 355 - 362 (1984)
Update date:2022-09-26
Topics:
Bunton, Clifford A.
Ljunggren, Sten
Aqueous cationic micelles of cetyltrimethylammonium surfactanst (CTAX;X = Br,Cl, or 0.5SO4) and dodecyltrimethylammonium bromide, and anionic micelles of sodium lauryl sulphate (NaLS) inhibit SN1 hydrolyses of sterically hindered arenesulphonates and chlorides.The substrates were 2-adamantyl p-bromobenzenesulphonate (brosylate) and p-nitrobenzenesulphonate, 1,2,2-trimethylpropyl (pinacolyl) tosylate, brosylate, benzenesulphonate, and p-methoxy- and p-nitrobenzenesulphonate, and 2,2-dimethyl-1-phenylpropyl chloride and tosylate.Micellar inhibition increases with increasing substrate hydrophobicity but is always larger with cationic than with anionic micelles by factors of between 2 and 5 for the arenesulphonate, and 10 for 2,2-dimethyl-1-phenylpropyl chloride.The difference is much larger for hydrolysis of diphenylmethyl chloride and bromide.For hydrolysis of 1-benzylbutyl tosylate, with nucleophilic participation by water, micellar inhibition is smaller than with the hindered substrates but greater with cationic than with anionic micelles.These micellar inhibitions are compared with those on deacylations which are dominated by bond-making and where reaction is faster in cationic than in anionic micelles.Micellar medium effects are related to the mechanisms of these spontaneous hydrolyses and to substrate structure.Substituent effects were examined for SN reactions in water; p ca. 1.5 for hydrolyses of pinacolyl arenesulphonates, and is similar for hydrolyses in micelles.
View MoreYicheng Goto Pharmaceuticals Co.,Ltd.
Contact:+86 710 3423122
Address:5th Floor,East Gate of Building #2,Servo-Industrial Park,1st Qilin Road,Xiangyang,Hubei,China
Jiangsu Institute of Ecomones Co., Ltd
website:http://www.jsmone.com
Contact:+86-519-82821700
Address:95 Huanyuan N. Road, Jintan, Jiangsu, China
Lishui Nanming Chemical Co., Ltd(expird)
Contact:+86-0578-2134101，2697830
Address:No.19 Tongji Road Shuige Industrial zone
Contact:86-512-69362780,69362785
Address:No.69 Weixin Road,Weiting Town,Suzhou Industrial Park
QINGDAO NEW FLOURISH INTERNATIOANAL TRADE CO., LTD.
Contact:+86 532 80861829
Address:No. 1, Yinchuan East Road, 266061, Qingdao, China
Doi:10.1002/anie.201504413
(2015)Doi:10.1039/a906624a
(1999)Doi:10.1021/jo00827a025
(1970)Doi:10.1021/ja01187a032
(1948)Doi:10.1021/ja063902u
(2007)Doi:10.1021/ja00332a070
(1984)
