Amidinium review

The reaction of a-chloroenamines with primary or secondary amines affords amidinium salts, e.g. (177 equation 100). In most cases not the amidinium salts but their deprotonation products (ketene animals or amidines) have been isolated these reactions have been reviewed. Imino compounds undergo cycloadditions with a-haloenamines in which a-azetidylideneammonium salts (178 equation 101) are formed. " Ynamines are converted to amidinium salts, e.g. (179), (180) and (181) (Scheme... 

Many vinylogous amidinium salts, e.g. (185) and (186) (Scheme 25), are readily available by double formylation of CHa-acidic or alkenic compounds. Reviews on the chemistry of vinylogous amidinium salts are available. The first azavinylogous foimamidinium salt (187 Scheme 26) was prepared in 1960 by reaction of DMF with cyanuric chloride. The mechanism of this reaction has been estab-lished. Based on these findings new methods for the synthesis of these compounds were developed, e.g. the reaction of isocyanatomethyleneiminium salts with tertiary formamides affords salts (187). In the synthesis of the salts (187) cyanuric chloride can be replaced by phosphorus nitride chloride (PNCl2)3. ... 

Similarly, diphenyl phosphate as amidinium salt 18 acts as a stable transition-state analogue for carbonate 19 and carbamate hydrolysis [27] (for a detailed review, see [1]). 

Isocyclics s. 25, 581 heterocyclics, also N-condensed, cf. Ang. Ch. 86, 781 (1974) vinylogous amidines and amidinium salts as stabilized push-pull ethylene derivs., review, s. D. Lloyd and H. McNab, Ang. Ch. 88, 496 976)... 

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