Helvetica Chimica Acta p. 2273 - 2280 (2006)
Update date:2022-08-17
Topics:
Baciocchi, Enrico
Del Giacco, Tiziana
Lapi, Andrea
A kinetic and product study of the reaction of a series of α-methyl-substituted N-methylpiperidines with thermally generated 1O2 in MeCN was carried out. It was found that as the number of α-methyl groups (Me in α-position relative to the N-atom) increases, the rate of 1O2 quenching (physical plus chemical) slightly decreases. This finding shows that, with respect to the reaction rate, steric effects are much more important than electronic effects as the latter should have produced the opposite result. The opposite outcome was instead found for the chemical quenching that leads to the N-demethylation products and N-formyl derivatives. The same trend was observed for the ratio between N-demethylation and formation of the N-formyl derivatives (NH/NCHO ratio). All these results are consistent with the mechanism reported in Scheme 1 where an exciplex is first formed that by a H-atom transfer process produces an α-amino-substituted C-radical. The latter forms the product of N-demethylation by one electron oxidation, or affords the N-formyl derivative by radical coupling (Scheme 1). Similar results were obtained with N,N-dimethylcyclohexanamine. However, this 'acyclic' amine exhibited behaviors quite distinct from those of the N-methylpiperidines series, with respect to reaction rate, extent of chemical quenching, and NH/NCHO ratio.
View MoreShijiazhuang Yunxuan Im&Export Co.,Ltd.
Contact:+86-311-83037514
Address:No.6 Hongbin Road
FUJIAN SHANSHUI CHEMICAL CORP.LTD.
Contact:+86-151-59920036
Address:Jinqiao Gareden, jo@fj-xinyi.com
Xinxiang Junlong Biological Technology Co., Ltd.
website:https://junlongbio.lookchem.com/
Contact:86-13525059581
Address:Xinxiang City, Henan Province
QINGDAO TAOSIGN INTERNATIONAL TRADE CO.,LIMITED
Contact:+86-0532-82683616
Address:RM1402, Doublestar Seacoase 7#, No. 5 Guizhou Road, Qingdao, Shandong, China
Contact:86-575-86132822,86-575-86085355
Address:No.418 Dadao West Road,Qixing Street,Xinchang, Zhejiang Province, China.
Doi:10.1007/BF01171726
()Doi:10.1002/cssc.201300404
(2013)Doi:10.1016/j.ejmech.2018.10.055
(2019)Doi:10.1002/ardp.19773100103
(1977)Doi:10.1016/S0040-4020(01)82588-6
(1967)Doi:10.1016/S0040-4039(00)84863-7
(1986)