Isocyanates azides

Few of the many other inorganic compounds of Ge, Sn and Pb call for special comment. Many pseudo-halogen derivatives of Sn, Pb and Pb have been reported, e.g. cyanides, azides, isocyanates, isothiocyanates, isoselenocyanates and alkoxides. ... 

Oxidation of Primary Amines, Oximes, Azides, Isocyanates, or Nitroso Compounds to Nitro Compounds... 

Oxidation of primary amines, oximes, azides, isocyanates, or nitroso... 

Nitrenes can be generated from many precursors such as azides, isocyanates, ylides, heterocycles, and nitro compounds.236,237 Amongst these, azides are the most convenient precursors since they are easily prepared and can be decomposed by heat, light or a suitable catalyst. Despite considerable endeavors, no one has yet provided a synthetically viable method to use azides as sources of nitrenes.237 The breakthrough of nitrene chemistry was the recognization of the value of A-arenesulfonyl iminoiodinanes (ArS02N=IPh) as nitrene precursors by Breslow and Mansuy. - They reported inter- and intramolecular C-H insertions by tosylimino phenyl-iodinane (TsN=IPh) in the presence of Mn(m) or Fe(m) porphyrins or [Rh2(OAc)4]. Subsequently, Muller... 

The acyl azide - isocyanate rearrangement is known to proceed stereospecifically with retention of both optical and geometrical (cis-tranSy endo-exo) configuration. Thus, optically active aminocyclopropanes were obtained from optically active cyclopropane carboxylic acid derivatives A lot of exo-amiobicyclo[n.l.O]alkanes or... 

Acyl azides isocyanates. The reagent undergoes metathesis readily with carboxylic acid chlorides in benzene or toluene. If the solution is heated to 50-90°, Curtius rearrangement leads to isocyanates in 60-90% yield. 

Sigurdsson et al. developed the synthesis of isocyanates from aliphatic amines [21]. Thus, the reaction of an aliphatic amine with trichloromethyl chloroformate (diphosgene) in the presence of Proton Sponge (1) (2 equiv.) at 0°C gave isocyanate in 81% yield. Azide isocyanate was synthesized from azide amine by means of a similar procedure by Keyes et al. [22] (Scheme 8.8). 

Preparation of Isocyanates. Isocyanates are prepared by rearrang-ii azides in inert solvents such as ethers, chloroform, benzene and its homologs, malonic ester, mid ligroin. If the isocyanate is to be isolated, the solvent is removed by distillation, or, if the isocyanate is the lower boiling, it is distilled directly. In this operation, a safety shield is advisable to guard against a possible explosion of yet undecomposed azide. Isocyanates can be converted to sym-ureas by reaction with water, to urethans by reaction with alcohols, to os-ureas by reaction with amines, or to acylamines by reaction with anhydrous acids or acid anhydrides, or they can be hydrolyzed directly to amines. Acylamines can also be obtained. from isocyanates by reaction with Grignard re-... 

Starting Material Hydrazide Azide Isocyanate Urethan Amine, etc. 

Diels-Alder addition of 2-chloroacrylonitrile and dienes gives the expected adducts, e.g. (310), which may be converted via azide, isocyanate, and hydrolysis to the ketone (311) in good yield. This constitutes a method for 1,4-addition of the methylenecarbonyl unit (—CHgCO—) to dienes. Among the many 1,3-dipolar additions of olefins recently reported are the intramolecular nitrone-olefin cycloadditionse.g. (312) (313), and the... 

Acid halides etc. initially arranged in the order of acids (see 5.), and then for each individual acid fluoride, chloride, bromide, iodide, azide, isocyanate, isothiocyanate, isocyanide, cyanide,... 

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