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Autocatalytic Radical Ring Opening of N ‐Cyclopropyl‐ N ‐phenylamines Under Aerobic Conditions − Exclusive Formation of the Unknown Oxygen Adducts, N ‐(1,2‐Dioxolan‐3‐yl)‐ N ‐phenylamines
Author(s) -
Wimalasena Kandatege,
Wickman Heang B.,
Mahindaratne Mathew P. D.
Publication year - 2001
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 - 10.1002/1099-0690(200110)2001:20<3811::aid-ejoc3811>3.0.co;2-6
Subject(s) - chemistry , oxidizing agent , autocatalysis , medicinal chemistry , adduct , hydrogen peroxide , peroxide , heteroatom , ring (chemistry) , catalysis , stereochemistry , organic chemistry
In contrast to the high stability of N ‐alkyl‐ N ‐cyclopropylamine derivatives, N ‐cyclopropyl‐ N ‐phenylamine ( 1a ) has been found to slowly convert into the hitherto unknown product N ‐(1,2‐dioxolan‐3‐yl)‐ N ‐phenylamine ( 1f ) at room temperature under aerobic conditions. The rate of this conversion was found to be significantly increased by the presence of a catalytic amount of the single‐electron oxidizing agent tris(1,10‐phenanthroline)Fe III hexafluorophosphate or of the hydrogen‐abstracting agents benzoyl peroxide or tert ‐butyl peroxide/UV light. Based on the regio‐ and stereochemical outcomes of aerobic ring‐opening reactions of some specifically ring‐methylated derivatives of 1a , namely N ‐(1‐methylcyclopropyl)‐ N ‐phenylamine ( 2a ), N ‐( trans ‐2‐methylcyclopropyl)‐ N ‐phenylamine ( 3a ), and N ‐( cis ‐2‐methylcyclopropyl)‐ N ‐phenylamine ( 4a ), as well as other experimental evidence, an autocatalytic mechanism analogous to that of the oxygenation of vinylcyclopropanes is proposed for the formation of the 1,2‐dioxolane product. The oxidative radical ring opening and related chemistry of these novel derivatives could be valuable in mechanistic studies of heteroatom‐oxidizing enzymes.