Ammonium perchlorate, proton transfer

The decomposition of a number of perchlorates containing substituted ammonium groups (various methylamines, guanadine etc.) [935—939] resemble the mechanism proposed for AP decomposition in that proton transfer is identified as the initial step. 

Pearson and Sutton [75] did not agree with this vicw On the basis of their own experiments and those of other authors [77, 82] that both the catalysed and uncataJysed decomposition of ammonium perchlorate proceeds by proton transfer (4) and (7) ... 

As will be discussed in the next section, 1,5-pentanediones are obtained by Michael addition of acetophenones to chalcones. The addition and cyclization may be merged in one step (see Section II,C,2,g). When acetophenone was condensed with chalcone (74) in the presence of BFg-EtaO or of HC104, jS-phenylpropio-phenone (76) was obtained as by-product its formation is due to hydride transfer to the conjugate acid of chalcone (75), which is the acceptor (experimental data and theoretical calculations show that chalcones are protonated at the oxygen atom). Balaban obtained a 72% yield in the conversion 70 -> 37 using as acceptor chalcone and as catalysts perchloric or sulfuric acids (i.e., 75). The formation of j8-phenylpropiophenone (76) in the Chichibabin synthesis of pyridines from chalcones and ketones in the presence of ammonium acetate, and in the pyrimidine synthesis from chalcones and amidines is undoubtedly due to a similar hydride transfer. 

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