Azines cross-coupling reactions

A unique reaction of allenylindium reagents, prepared from propargyl bromides and indium, and haloazines gives rise to the appropriate allenyl-azines. Although the reaction is not a Heck coupling, but a cross-coupling reaction, the aryl moiety is formally attached to a carbon-carbon multiple bond, therefore we mention it here. 

Campeau L-C, Fagnou K (2007) Applications of and alternatives to 7c-electron-deficient azine organometallics in metal catalyzed cross-coupling reactions. Chem Soc Rev 36 1058-1068... 

Cu(l)-diamine complexes were found to catalyze the trifluoromethylation of other heterocycles. In the presence of a small amount of CuX (X=C1, Br, I) and 1,10-phenanthroline, the cross-coupling reactions of iodoazines with trifluorometh-ylsilanes proceeded smoothly to afford trifluoromethylated azines in good yields [169]. For example, trifluoromethylazines 277, 279 have been synthesized in good yields [169] by such method from iodoazines 276,278 (Scheme 82). 

Bi, Zhang et al. reported a novel Cu(OTf)2-catalyzed preparation of benzox-azine derivatives from readily available Af-para-tolylamides in the presence of Selectfluor and water through the intermolecular C-H-activated dehydrogena-tive cross-coupling reaction (Scheme 8.111). The C(sp )-H bond of benzylic methyl and C(sp )-H bonds of arene were activated, and new C-C and C-O bonds were formed. The desired benzoxazine derivatives could be obtained in good to excellent yield. However, the substrates such as Af-para-tolylacetamide, 3-methyl-JV-p ra-tolylbutanamide, and 2-phenyl-M-para-tolylacetamide have... 

The transition metal catalyzed carbon-carbon bond formation between organomagnesium reagents and aryl (vinyl) halides has been one of the pioneering entries into cross-coupling chemistry. The reaction has been widely utilized since than in azine chemistry,22 with the limitation that the functional group tolerance of Grignard reagents is only moderate. Here only some of the more recent developments will be mentioned. 

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