Azides, aroyl synthesis

A sulphamoyl azide has also been used in the synthesis of a phosphazenyl-stabilized ylide (16).28 Aroyl azides react readily with triarylphosphines to give phosphazenes... 

Zinc chloride-doped natural phosphate was shown to have catalytic behavior in the 1,3-dipolar cycloadditions of nucleoside acetylenes with azides to form triazolonucleosides <99SC1057>. A soluble polymer-supported 1,3-dipolar cycloaddition of carbohydrate-derived 1,2,3-triazoles has been reported <99H(51)1807>. 2-Styrylchromones and sodium azide were employed in the synthesis of 4(5)-aryl-5(4)-(2-chromonyl)-1,2,3-triazoles <99H(51)481>. Lead(IV) acetate oxidation of mixed bis-aroyl hydrazones of biacetyl led to l-(a-aroyloxyarylideneamino)-3,5-dimethyl-l,2,3-triazoles <99H(51)599>. Reaction of 1-amino-3-methylbenzimidazolium chloride with lead(fV) acetate afforded l-methyl-l/f-benzotriazole <99BML961>. Hydrogenation reactions of some [l,2,3]triazolo[l,5-a]pyridines, [l,2,3]triazolo[l,5-a]quinolines, and [l,2,3]triazolo[l,5-a]isoquinolines were studied <99T12881>. 

Reduction of Azides to Amines. In situ generated TMSI has been found to be a useful reducing agent for the reduction of azides to amines (eq 56). The reaction is carried out under extremely mild and neutral conditions, and a number of aryl, alkyl, and aroyl azides are suitable for this tranformation. This methodology has also been applied to the synthesis of pyrrolo[2,1-c][l,4]benzodiazepines via reductive cyclization of w-azido carbonyl corrqtounds. ... 

A one-pot protocol for the synthesis of 1-aryl-5-(N-aryl-N-aroylamino)-tetrazoles 247 from symmetrical diaryl carbodiimides 243 with sodium azide under phase transfer conditions in toluene at room temperature was developed by Ding and Weber. The carbodiimide 243 reacts with sodium azide to form a guanyl azide 244 which, after reaction with an aroyl chloride 245, imdergoes electrocycHzation to yield the substituted tetrazole 247 (Scheme 47). The reaction is limited to symmetrical diaryl carbodiimides. Di-aUcyl carbodiimides fail to react imder these conditions while asymmetrical diaryl carbodiimides lead to a mixture of tetrazole isomers [157]. 

Chen DJ, Chen ZC (2000) Hypervalent iodine in synthesis. Part 54 one-step conversion of aryl aldehydes to aroyl azides using a combined reagent of (diacetoxyiodo)benzene with sodium azide. Tetrahedron Lett 41(38) 7361-7363... 

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