Dimethylaluminum amide

On treatment with two equivalents of dimethylaluminum amide (Me2AlNH2), carboxylic esters can be converted to nitriles RCOOR —> RCN. This is very likely a combination of 10-58 and 17-32. See also 19-5. 

CONVERSION OF ESTERS TO AMIDES WITH DIMETHYLALUMINUM AMIDES N,JV-I>IMETHYLCYCLOHEXANECARBOXAMIDE... 

AMIDES FROM ESTERS WITH DIMETHYLALUMINUM AMIDES... 

This procedure, which is based on the work of Ishii and co-workers, affords a mild and general method for converting a wide variety of esters to primary, secondary, and tertiary amides (Table 1). While the preparation of the tertiary amide, N,N-dimethylcyclohexanecarboxamide, described here is carried out in benzene, aluminum amides derived from ammonia and a variety of primary amines have been prepared by reaction with trimethylaluminum in dichloromethane and utilized for aminolysis in this solvent. Although 1 equivalent of the dimethylaluminum amides from amines was generally sufficient for high conversion within 5-48 hours, best results were obtained when 2 equivalents of the aluminum reagent from ammonia was used. Diethyl-aluminum amides can also effect aminolysis, but with considerably slower rates. 

AmidesThese reagents are prepared by reaction of A1(CH3)3 in tolugne with I lie hydrochloride salts of NH3, H2NCH3, and HN(CH3)2. They are easier to prepare Ihun dimethylaluminum amides (8, 182), but they are equally suitable for conversion of esters to amides. 

NITRILES Chlorosulfonylisocyanate. Dimethylaluminum amide. Hydroxyl-amine. Hydroxylamine-O-sulfonic acid. Selenium dioxide. Triethoxydiiodophos-phorane. Trifluoroacetic anhydride-Pyridine. Trimethylamine-Sulfur dioxide. 

The trimeric dimethylaluminum amide, [Me2Al(NH2)]2 (19), was originally used as a single source precursor for growth of AIN under LPCVD conditions using a hot walled reactor [192], although subsequent deposition was also demonstrated in a cold walled system [193]. While the films showed promise as fiber coatings for composites, film quality was never demonstrated for electronic applications. 

Dimethylaluminum amides, (CH3)2AINR R . The reagents are prepared by addition of trimethylaluminum in hexane (Alfa) to a solution of ammonia or an amine in CH2CI2 (Na). 

Dimethylaluminum amides, 182 Dimethylaluminum chloride, 42 Dimethylaluminum methyl selenolate, 182-183... 

Scheme 3 Reaction of qjoxy ethers 3 with dimethylaluminum amide and reduction.

So, we were able to prepare selectively syn and anti trifluoromethyl amino alcohols. The next step was a search for a chiral approach to these compounds. Two approaches have been investigated to obtain chiral anti amino alcohols first we performed the reaction of epoxy ethers 3 with the chiral dimethylaluminum amide, prepared from the fi -phenethylamine and MeaAl (Scheme 5). From 3a, the reaction was effective leading, after reduction to the anti diastereoisomers 8a and 9a stereoselectively (Scheme 5). However, the chiral amine induced no selectivity anti amino alcohols 8a and 9a were obtained in a 50/50 mixture. Their separation was performed by crystallisation of the mandelate salts. Although this access to homochiral anti amino alcohols is somehow tedious, it is general since oxirane ring opening is efficient whatever the R substituent, and since epoxy ethers, substituted with various fluoroalkyl groups, are available. ... 

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