Aluminum dimethylamide

Materials. The complex RhCl(ttp) was prepared as described previously (6). Cyclohexanone was obtained from Mallinkrodt cyclohexene and 1-pentene were obtained from MCB. All other olefins and 1-octyne were purchased from ChemSampCo. The aluminum alkyls were obtained from Aldrich as 25% w/w solutions in toluene. Neat liquids used in the H-l NMR work were obtained from these solutions by removing the toluene under vacuum. Lithium dimethylamide, LiN(CH3)2, was obtained from Alpha/Ventron as a 10% w/w slurry in hexane. Hydrogen was passed through an Englehard Deoxo purifier and activated alumina before use. 

Just as considerable effort has been exerted to utilize LiAlH4 or its derivatives for the selective reduction of amides to aldehydes, so too has much exertion gone into the use of diisobutylaluminum hydride. This area has been reviewed. " With DIBAH itself in diethyl ether at 0 °C, A -methylanilides furnish aldehydes in yields of 25-70%, the remainder of the reaction products being mostly amines. The yield of aldehyde drops severely above 0 °C. DIBAH, tempered by the addition of various amines, has been discussed in Section 1.11.2 (ref. 5) and Section 1.11.4 (ref. 60). One of these reagents, bis(4-methyl-l-piperazinyl)aluminum hydride has been recommended for the reduction of dimethylamides (and other amides) to aldehydes in 65-80% yield." The hydride is mild enough for it to be necessary to reflux the amide in diethyl ether with the reagent for several hours. It should be noted that under such conditions acids and esters will be reduced also. 

Sodium aluminum hydride has been found to be superior to lithium aluminum hydride for reduction of dimethylamides of carboxylic acids to aldehydes. 

Organoaluminum compounds also undergo insertion reaction with isocyanates. For example, aluminum trialkyls react with alkyl and aryl isocyanates to give carboxylic acid amides after hydrolysis . Alkyl aluminum chlorides react similarly . Aluminium trichloride also forms insertion products with isocyanates Diethylaluminum ethyl thiolate or dimethylamide react with equimolar amounts of alkyl or aryl isocyanates to give the expected insertion products 274. ... 

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