Journal of the Chemical Society. Perkin Transactions 2 (2001) p. 2505 - 2509 (1996)
Update date:2022-08-12
Topics:
Gobbi, Alessandro
Landini, Dario
Maia, Angelamaria
Penso, Michele
Cation electrophilic catalysis has been studied in nucleophilic substitution reactions of octyl methanesulfonate (1) promoted by complexes of macrocyclic polyethers 2-5 with alkali and alkaline-earth metal salts in chlorobenzene. The catalytic effect increases with increasing Lewis acid character of the cation, in the order Cs+ ～ Rb+ ～ K+ < Na+ < Li+ and Ba2+ < Sr2+ < Ca2+, and is mainly related to the ability of the polyether to shield the metal ion charge. Kinetic data clearly indicate that crown ethers 2-4 allow the metal ion participation in the activation process, whereas the cryptand [2.2.2,C10] (5), which more effectively binds the cation, inhibits catalysis. The lower reactivity of the complexes of alkaline-earth metal salts with both crown ethers and cryptands is most likely due to a higher interaction of the divalent cation with the anion in the ion-pair.
View More
Contact:
Address:
Contact:732.938.2777
Address:5012 Industrial Road Farmingdale, NJ 07727
Chemsigma International Co.,Ltd.
website:http://www.chemsigma.com
Contact:86-025-58748998
Address:Rm.705, 15th Building,Rd.Xinke II
Chengdu Pukang Biotechnology Co., Ltd
Contact:+86-28-82550498
Address:No. 558 Rulin Road,Xinjin county,Chengdu city, China
Suzhou BEC Fine Chemicals Co., Ltd.
website:http://www.bek.com.cn
Contact:0512-68095917 18913193865
Address:6, Jin Shan Road, Suzhou New District, 215011 China Suzhou Nations Pharmaceutical Innovation Center Inside
Doi:10.1002/jccs.201200628
(2013)Doi:10.1039/c6dt01330a
(2016)Doi:10.1021/ja210703y
(2012)Doi:10.1021/ol052160r
(2005)Doi:10.1016/j.jorganchem.2007.10.008
(2008)Doi:10.1002/anie.201707491
(2017)
