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A Tunable One‐Step N , N ′‐Disubstitution of 1,4,8,11‐Tetraazacyclotetradecane with Acrylamide
Author(s) -
Fensterbank Hélène,
Berthault Patrick,
Larpent Chantal
Publication year - 2003
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/ejoc.200300133
Subject(s) - chemistry , protonation , cyclam , regioselectivity , reactivity (psychology) , yield (engineering) , chloroform , medicinal chemistry , structural isomer , stereochemistry , organic chemistry , catalysis , metal , ion , medicine , materials science , alternative medicine , pathology , metallurgy
N , N′ ‐disubstitution of cyclam without the use of protecting groups was investigated. This macrocycle reacted with two equivalents of a Michael acceptor in chloroform to yield as a major isolated compound the 1,8 di‐ N , N′ ‐substituted macrocycle. Running the same reaction in the presence of one equivalent of para ‐toluenesulfonic acid led to the 1,11‐di‐ N , N′ ‐substituted macrocycle as the major product. Each regioisomer has been isolated and fully characterized. The observed regioselectivity is discussed with respect to the reactivity of the unprotonated or protonated monoalkylated intermediate. A site of protonation for the latter intermediate is deduced from an NMR study. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)