Halides ethylene derivs., terminal

Potassium tert-butoxide Terminal ethylene derivatives from halides Direction of elimination s. 11, 953 a-Allylketones... 

Considering functionalized olefins first, only three two-carbon reactants are listed above. Ethylene itself can give only terminal double bonds when elimination is facile and triethylamine functions as the base. If nucleophilic secondary amines are necessary, ethylene produces internal amines almost entirely. Aryl halides react well with ethylene to produce styrene derivatives. 

From propylene oxide these catalysts yield crystalline, isotactic polymers. Living polymerizations with metalloporphyrin derivatives are difficult to terminate and are therefore called by some immortal Catalysts like (C6H5)3-SbBr2-(C2H5)3N in combination with Lewis acids also yield crystalline poly(propylene oxide). Others, like pentavalent organoantimony halides, are useful in polymerizations of ethylene oxide. 

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