Aryl azides diazo transfer

The hazardous nature (see Tetrazoles below) of some alkyl azides limits the method in these cases, however A-alkyl- (benzyl) -1,2,3-triazoles can be obtained by preparing the azide in situ, for example using a mixture of sodium azide, the alkyne and a benzyl hahde in situ preparation of aryl azides is also feasible. An alternative method in which the alkyl azide is also generated in situ, is to use a diazo transfer to a primary amine the diazo transfer requires Cu(II) and the cycloaddition needs Cu(I) so a reducing agent is added together with the alkyne following the first phase. ... 

Diazo transfer to pyrazolidone (39) using azidinium salt (38) affords diazo pyrazolidone (41) and imine 40 this method has proved superior to the aryl sulfonyl azide reactions in cases where azo coupling occurs. 

Diazo transfer. Diazo transfer from tosyl azide to aryl amines can be effected V phase-transfer catalysis. ... 

Related Reagents, p-toluenesulfonyl azide and methane-sulfonyl azide have been used widely for diazo transfer to stabilized enolates. The latter reagent simplifies isolation of the desired product, but is potentially explosive and must be handled with care. Relative to other aryl analogs, the electron-deficient p-nitrobenzenesulfonyl analog favors diazo transfer to imide enolates. ... 

Other PT processes reported recently include the phosphorylation of amines " or alcohols, and the conversion of aromatic amines to azides by diazo transfer (Equation 8) to the amine anion. An interesting recent development is the use of PTC in organometallic chemistry, notably the conversion of aryl halides to carboxylic acids mediated by a Pd complex (Equation 9). 

The starting diazoacetamide is prepared by N-arylation of /-phenylalanine methyl ester (DMP, 5.5 M 4-fluoronitrobenzene, 110°C, lOh, 30%), acetoa-cetylation (2,2,6-triraethyl-4/7-l,3-dioxin-4-one, toluene, 110 °C, 4h, 71%) and diazo group transfer (tosyl azide, triethylamine, acetonitrile, 20 °C, 1.5 h, 90%). 

Indole and its derivatives may be considered as enamines. Their reaction products with azides demonstrate, however, that in most cases complex dediazoniation products are formed rather than diazoalkanes. Their structure was elucidated mainly by Bailey s group (review Peach and Bailey, 1979). Under phase transfer conditions 2-aryl- or 2-heteroaryl-substituted indoles are converted into the corresponding 3-diazo-3//-indoles by 4-toluenesulfonyl azide (2-70) (Gonzalez and Galvez, 1981). 

Although azide reagents have been utilized in a number of chemical transformations, to date PS-TsA has only been utilized for the direct transfer of a diazo function to methylene groups flanked by either two carbonyls (eq 2), a carbonyl and an aryl sulfonyl (eq 3), or the methylene of lO/ anthracen-9-one. Diazodicarbonyl compounds such as 5-diazo-2,2-dimethyl-[l,3]dioxane-4,6-dione, 2-diazo-3-oxo-butyric acid ethyl ester, lO-diazo-lO/ anthracen-9-one, 2-diazo malonic acid diethyl ester, and 2-diazo-3-oxo-butyric acid ter/-butyl ester, as well as... 

---