Diamines aminonitriles

The use of guanidine for cyclization gives amino substituted derivatives (e.g. 212) (52CB1012), and in this case o-aminonitriles may be used to furnish diamines (e.g. 8UOC1394). An unusual reaction involving nitriles occurred during the preparation of nicotinonitrile from the amide and ammonium sulfamate, when a 60% yield of the dimeric by-product (213) was formed via the nitrile (69BSB289). Similar products have been obtained from... 

Like the nitronate ion, the cyanide ion is synthetically equivalent to the aminomethyl carbanion (CH2NH2) , because of the possible reduction of - CN to the - CH2NH2 group. Consequently, the addition of cyanide ion to imines to give a-aminonitriles (Strecker-type reaction) is a viable route to 1,2-diamines. As a matter of fact, a number of diastereoselective and catalytic... 

Optically pure a-amino acids can be converted to 1,2-diamines by a route that involves the preliminary formation of N-protected a-aminonitriles through the intermediate amides. The addition of organometallic reagents to these a-aminonitriles gives a-amino ketimines, which are then reduced in situ to 1,2-diamines. However, this route has been scarcely applied to acychc a-aminonitriles. As a matter of fact, the sequential addition of methylmag-... 

Scheme 37 Asymmetric synthesis of 1,2-diamines from chiral a-aminonitriles derived from diastereoselective aldolization...

The asymmetric Mannich addition of carbon nucleophiles to imines catalyzed by the cyclohexane-diamine catalysts has developed significantly in the past decade. List and co-workers reported the asymmetric acyl-cyanantion of imines catalyzed by a cyclohexane-diamine catalyst [103], Using a derivative of Jacobsen s chiral urea catalyst, the authors optimized reaction conditions and obtained chiral iV-acyl-aminonitriles in high yield and enantioselectivities (Scheme 51). The scope of the reaction was explored with both aliphatic and aromatic imines, providing good to high selectivities for a variety of substrates. 

In NC(CH2)nCN Conversion (%) Aminonitrile Cyclic Imine Diamine Dimeric product... 

P-morpholinopropionitrile equilibrium at a high temperature. Freifelder obtained good yields of diamines by low-pressure hydrogenations over Rh-Al203 of P-, y-, and 8-di alkyl aminonitriles.100... 

Recently, a new type of reaction - that is, aerobic oxidative cyanation of tertiary amines - was discovered. In this reaction, oxidation with molecular oxygen in place of peroxides, in addition to direct carbon-carbon bond formation by trapping of the iminium ion intermediates with a carbon nucleophile under oxidative conditions, is accomplished simultaneously. The ruthenium-catalyzed oxidation of tertiary amines with molecular oxygen (1 atom) in the presence of sodium cyanide gives the corresponding a-aminonitriles (Eq. 3.74) [132], which are useful for synthesis of a-amino acids and 1,2-diamines. 

Low-pressure hydrogenation of a-aminonitriles occurs without hydrogenolysis over platinum oxide in acetic anhydride (to the a,j8-diacetamido compound) or in alcohol-HCl (to the a,jS-diamine) . This procedure is not applicable to N-substituted amino-nitriles that are efficiently reduced using rhodium-on-alumina in alcoholic ammonia [equation (h)] the catalytic system also reduces )8-, y-, 5-aminonitriles to diamines. 

In our conditions, we have only observed secondary imines and secondary amines. Moreover, we have shown that the C-N impurities are mainly produced during the hydrogenation of aminonitrile to diamine. They correspond to the reaction of primary diamine with aminoimine intermediate. 

C-C by-products formation occurs during the hydrogenation of dinitrile into aminonitrile, while C-N by-products are formed during the second stage of the hydrogenation ie from aminonitrile to diamine. 

Hydrogenation of the aminonitrile with a Raney catalyst leads to a family of branched diamines. Because of the branching, most of the aminonitriles and diamines are liquids at low temperature and have low freezing points. They have found markets as comonomers or curatives, since they lower polymer viscosity, crystallinity, and glass transition temperature. Catalytic hydrogenation of MGN with a Raney catalyst gives the branched-amine methylpentamethylenediamine, MPMD, and 3-methylpiperidine (3MP) shown in equation 3. The product is dependent on conditions and choice of catalyst. The MPMD was initially isolated from plant streams to develop the market. Many applications were found as a polymer additive in... 

The aldehyde can also react stepwise with an amine and HCN within the framework of a Strecker synthesis (Scheme 5.147) [37]. The methodology tolerates a broad range of substituents in the starting olefin (acychc, cyclic, phthalimide) as well as different amines. The a-aminonitriles formed can be hydrolyzed to produce a-amino acids. Upon hydrogenation, 1,2-diamines are accessible. The latter were used, for example, for the construction of amino-functionalized dendrimers. 

Acylamidines a, a-Alkoxy aminonitriles N-Cyaniminoesters Diazo oxides Monoacyl-1,1-diamines... 

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