“…• with olefins as substrates for the cleavage of olefins or for the aromatization of cyclic olefins, 30,39,41,42 • with amines as substrates, oxidation to amides, imines 40 or with N-N coupling to diazo compounds, 5 • with diphenyl methanes as substrates, leaeding to oxidation to benzophenone 43 or with oxidative dimerization to 1,1,2,2-tetraphenylethane, 44 • with aromatic aldehydes as substrates leading to oxidation to carboxylic acids 5 , • with phosphines as substrates leading to oxidation to phosphine oxides. 5 Barakat et al has shown that carboxylic acids (Table 1, entries 1-6), α-hydroxycarboxylic acids (Table 1, entries 7-9) or α-aminocarboxylic acids (Table 1, entries 10-13) react with Mn(IV) oxide with decarboxylation or with ammonia elimination producing the corresponding carbonyl compounds (Table 1). Barakat et al assumed that the formation of ethylene from two citric acid molecules occurs through the reaction of two carbene intermediates.…”