First Study of Syntheses and Reactivity of Grignard Compounds in the Diazine Series. Diazines. Part 27
摘要:
A preparation of Grignard derivatives of diazines is described using a halogen magnesium exchange reaction. This convenient method allows the functionalization of these rings at 0 degrees C or even room temperature. (C) 1999 Elsevier Science Ltd. All rights reserved.
Barbier type reaction with lithium metal has been tested under sonication on pyridines, a cinnoline and on various diazines. This very convenient method allows a very fast and smooth functionalization of these heterocycles.
Highly functionalized organometallics are efficiently prepared in larger quantities (up to 4 g) by directed ortho-metalation using the previously reported amide bases TMP2Mn˙2MgCl2˙4LiCl (TMP = 2,2,6,6-tetramethylpiperidyl), TMP2Fe˙2MgCl2˙4LiCl and TMP3La˙3MgCl2˙5LiCl. The resulting organometallics undergo various reactions with electrophiles like acid chlorides, alkyl iodides, or aldehydes and provide