Journal of the Chemical Society. Perkin transactions II p. 1117 - 1120 (1986)
Update date:2022-08-03
Topics:
Pruszynski, Przemyslaw
Jarczewski, Arnold
Kinetic studies have been carried out on the proton-transfer reactions of (i) 4-nitrobenzyl cyanide (4-NBC) with tetramethylguanidine (TMG) and (ii) 4-nitrophenylphenylcyanomethane (4-NPPCM) with 1,8-bis(dimethylamino)naphthalene (DMAN) in acetonitrile.The reaction (i) has a moderate enthalpy of activation (ΔH++ = 25 kJmol-1) and a negative entropy of activation (ΔS++ = -98 Jmol-1K-1).The deuterium kinetic isotope effect is large.The reaction (ii) of the more hindered molecule 4-NPPCM and DMAN has similar activation parameters (ΔH++ = 26 kJmol-1, ΔS++ = -140 Jmol-1K-1), but the kinetic isotope effect is considerably larger; also ΔHD++ - ΔHH++ is larger (13 kJmol-1) and AH/AD is small, indicating a considerable tunnelling effect.Evidence that the larger isotope effect are not artefacts of hydrogen exchange is presented.The tunnelling factor is estimated.
View MoreHangzhou Sartort Biopharma Co., Ltd
website:http://www.sartort.com
Contact:86-571-87039693
Address:No. 57, Tech Park Road, Hangzhou, Zhejiang, China
Zhengzhou Yuanli Biological Technology Co., Ltd.
Contact:+86-371-67897870/67897895
Address:No. 38, Qingyang Street, Zhengzhou, Henan, China
Contact:+86-21-38122007
Address:2, Lane 1123, Kangqiao Road, Pudong New Area, Shanghai
shanghai hekang chemical co.ltd
Contact:021-54173790
Address:328 WuHe Road, Building #A, 2nd Floor, Minhang, Shanghai 201109, China
Zhengzhou Xinlian Chemical Tech Co. ,Ltd
Contact:0371-65771781 021-52042910
Address:H Part, Building I, No. 700 Gonglu Road, Pudong New Area, Shanghai
Doi:10.1002/cplu.201402072
(2014)Doi:10.1016/j.ejmech.2009.06.029
(2009)Doi:10.1021/jo060334s
(2006)Doi:10.1039/b605278a
(2006)Doi:10.1016/j.tetlet.2006.04.132
(2006)Doi:10.1016/j.bmcl.2007.10.055
(2007)
