Amidines azidation

Azidoformamidine or Guanylazide (Triazo-formamidin, Carbamid-imid-azid or Kohlen-saure-amidin-azid, in Ger), N3C(=NH)NH2 mw 85.07, N 82.33%, OB -65.9% Prepd... 

Azidoformomidine or Guanylazide (Triazo-fotmamidin, Carbamid-imid-azid or Kohlen-saure-amidin-azid, in Ger), N3C(=NH)NH2 mw 85.0 7, N 82.33%, OB -65.9%- Prepd from the nitrate salt (which was prepd from aminoguanidine nitrate and nitrous acid) by treatment with NaOEt in ale, but quickly rearranged to the Tetrazole. Consequently, it is known only as its salts Ref l) Beil 3, 130, (60) 2391... 

Addition on to the exocyclic C—C double bond of an alkylideneaziridine also occurs when this compound is allowed to react with organic azides (75JOC2045). The initially formed spirotriazolines (332) are converted into four-membered ring amidines (334) with extrusion of molecular nitrogen. In the case of phenyl azide, the amidine (334) is obtained alongside the triazoline (333). 

Azines have been prepared by initial condensation of diethoxyphosphinyIhydrazine anions with aldehydes or ketones (Scheme 9). Phosphoryl azides undergo 1,3-dipolar cycloaddition to 2-tetralone enamines to give triazolines, possibly en route to amidines. A full paper on the addition of diethyl dibromophosphoramidate to alkenes(leading to the synthesis of 2-bromoalkylamines) has appeared. ... 

Chang et al. reported a mild tandem intramolecular hydroamination of yne amines to form an endo-adduct intermediate, which reacts with electron-deficient azides to produce cyclic amidines <06JA12366>. Selected examples of an interesting synthetic route to tropene derivatives 165 via a dual hydroamination strategy is shown below. This one-step reaction makes use of a palladium catalyst and takes place by sequential intermolecular hydroamination of cycloheptatriene with aryl, heteroaryl, and primary alkyl amines to generate intermediate 166, followed by transannular intramolecular hydroamination <06JA8134>. 

Triazoles have also been obtained when the carbon atom adjacent to the activated methylene group carries a nitrogen function (i.e., amides, nitriles, amidines, and imines - ). In many of these cases it is impossible to decide, without N-labeling experiments, whether the third nitrogen of the triazole ring is derived from the toluene-p-sulfonyl azide or from the activated methylene compound. With amides, amidines, and nitriles, the first possibility seems more reasonable, but with imines, the third nitrogen is that of the imino group (Scheme... 

N,N-Disubstituierte N -(4-Methyl-benzolsulfonyl)-amidine, die sich z.B. durch Cycloaddition von 4-Methyl-benzolsulfonyl-azid an Enamine und spontane Folgereaktionen herstellen lassen, konnen mittels Lithiumalanat direkt zu tert. Aminen reduziert werden1. 

Azidocyanfprmamicf ine See under Cysnform-amidine and Beil 3, [102] Azidocyaniminoaminomethane, See under Cyaniminoaminomethane and Beil 3, [102] Azidoeyelohoptone, See Cycloheptyl Azide under Cycloheptane and J.H.Boyer et al,... 

Enamines contain electron-rich double bonds and thus react readily with azides (in many cases at room temperature). Only one addition product is formed, namely a 5-amino-A2-triazoline, a result of electronic control.22 -223 Thus l-(p-nitrophenyl)-4-ethyl-5-morpholino-A2-triazoline (44) arises from the addition of p-nitrophenyl azide to 1-morpholino-l-butene (43). The addition products rearrange by heating into amidines (45).224... 

Enamines react with aryl azides to give 5-arnino-A -triazo-lines which can be thermolyzed to amidines (see preceding... 

Sulfonyl azides react rapidly (at room temperature) with enamines, and here, too, no triazolines are isolated. The reaction products nevertheless can be easily explained when an intermediate triazoline is postulated. The hypothetic triazoline can then decompose in three different ways leading either to amidines and nitrogen, or to amidines and diazoketones, or to triazoles and sulfonamines.226-241-270-272 A typical example of each mode of decomposition is given in Scheme IX. 

Although fluorine is known to be a rather poor leaving group in substitution reactions, some examples have been reported for the replacement of fluorine by N-nucleophiles. Here, substitution can proceed with amines,1 -3 amides,4 amidines,5-6 hydrazines3-7 or azides.8-9 Nitriles in the presence of nitrosyl hexafluorophosphate replace fluorine in alkyl fluorides, in a Ritter-like reaction, to form tV-alkylnitrilium species, which are hydrolyzed to amides.10... 

Although the addition of arylsulfonyl azides to enamines usually leads to amidines by loss of nitrogen from the intermediate triazoline adduct, when an electron-withdrawing substituent is present in the -position of the... 

An unusual course of thermolysis occurs in 5-amino- and 5-alkoxytri-azolines, which are formed only as intermediates in the reaction of enamines and enol ethers with azides bearing electron-withdrawing groups it involves cleavage of the N-l/N-2 as well as the C-4/C-5 bonds of the triazoline ring to yield diazoalkanes and imines with one fewer carbon than in the triazolines (amidines and imino ethers) (Scheme 144)233.250 272 431-433 in a cycloelimination reaction, the reverse of diazoalkane-imine cycloaddition. The intermediate formation of a diazonium zwitterion is suggested,233,247 but whether the thermolysis occurs in a one- or two-step reaction is not established. 

Amidines are also formed from less stable 1-hetaryl-220 and l-styryl-5-aminotriazolines.222,492,493 Thermolysis of the latter provides a method of synthesis of novel l-amino-2-azabutadienes (Scheme 176)492,493 Whereas cyanogen azide addition to dihydropyridines leads to bicycloazir-idines,241-243 addition of ethyl azidoformate yields the corresponding amidine 494 Likewise, indoles (103) react with picryl and sulfonyl azides to give... 

The cyclic sulfates undergo ring opening with a wide variety of nucleophiles, such as hydride, azide, fluoride, benzoate, amines, and Grignard reagents. The reaction of an amidine with a cyclic sulfate provides an expeditious entry to chiral imidazolines 21 and 1,2-diamines (Scheme 9.27).169... 

Aziridine formadon from arylnitrenes, rather than via tiiazolines, is known for highly fluorinated arenes. Phenyl azide with trifluotoacetic acid generates a nitrenium ion which adds stereospecifically to alkenes to give aziridines. Yields are rather low, pardy due to concurrent ring opening of the aziridine by addidon of trifluoroacedc acid. Similar reacdons can be adiieved with Lewis acids such as AlCb. Enamines with aryl azides can yield either 2-aminoaziridines or amidines. ... 

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