作者:Robert G Brinson、Paul B Jones
DOI:10.1016/j.tetlet.2004.06.049
日期:2004.8
The intramolecular keto-ene/cyclization tandem reaction of gamma-N-allylamino ketones is an effective means of producing 1,3-oxazines. The reaction usually requires high temperatures and/or pressures. We discovered that N,N-diallyl amines undergo the reaction at lower temperatures than their monoallyl analogs. An extreme example, 1-N,N-diallylamino-9,10-anthraquinone, undergoes the keto-ene reaction near ambient temperature. In the case of 1-N,N'-dialkylaminoanthraquinones, electron deficient ene components can even be used, allowing the preparation of a broad spectrum of oxazines. Furthermore, the N-allyl-1,3-oxazine can be easily deallylated to produce a 1,3-oxazine that contains a secondary amine. (C) 2004 Elsevier Ltd. All rights reserved.