1.1- Dinitrile groups

Nytril fiber n. A manufactured fiber containing at least 85% by weight of a long chain polymer of vinylidene dinitrile [-CH2-C (CN)2-] and having the vinylidene dinitrile group in no less than every other unit in the polymer chain (FTC definition). Nytril fibers have a low softening point so they are most commonly used in articles that do not require pressing such as sweaters and pile fabrics. They are also blended with wool to improve shrink resistance and shape retention. 

A stronger donor, the butadiene with the amino groups in place of the methoxy group in the 1,4-positions, was calculated to react with TCNE via a zwitterion (pseudoexcitation band in Scheme 7) [34], The loss of the stereochemical integrity was observed inthe[4+2]cycloadditionreactionsbetweensomestrongdonors,l,4-bis(dimethylamino) butadienes, and acceptors, fumaric and maleic dinitriles [36],... 

Our laboratory has investigated adsorption behavior at air/water and Hg/water interfaces, the adsorption potentials caused by the aliphatic nitriles," dinitriles,monoalkyl ethers" dialkylethers" propalgyl alcohol, and dimethysulfoxide. The influence of the relative positions of two OH groups using the isomeric butanodiols has been also studied. ... 

As expected, there was no formation of stilbenes or a dinitrile product and, more surprisingly, in all of the reactions reported only 5-7% of the allyltrimeth-ylsilane self-metathesis product was observed. It was proposed that this lack of allylsilane self-metathesis was due to the steric bulk of the TMS group reducing the reactivity of the Me3SiCH2 substituted alkylidene. In a more recent report by Blechert and co-workers it was noted that allyltrimethylsilane and its hydrocarbon equivalent (4,4-dimethylpent-l-ene) had comparable reactivities in the cross-metathesis reaction [28], further suggesting that the selectivity arises from steric rather than electronic effects. 

Porphyrazines are typically synthesized by a templated cyclization of substituted dinitriles, Fig. 2 (2). The most common divalent metal used as the template for this reaction is Mg2+, usually as the butoxide or propoxide, although other group 1(1 A) and 2(IIA) metals have been reported (41). Mixed cyclizations, which utilize two different dinitriles, Fig. 3, in principal, would give a statistical mixture of six different products or isomers. The truly enabling synthetic foundation for modem pz chemistry is the development of strategies directed toward the synthesis... 

Synthesis. The first example of a stable, soluble pz peripherally substituted with a heteroatomic moiety involved appended thioether groups, M[pz(.V-Mc)8, as reported in 1980 by Schramm and Hoffman (2) (Scheme 9, 45-48). Mg[pz(5 -Me)s], 46, was prepared in a 60% yield by a magnesium templated macrocyclization of dinitrile, 45. Demetalation with sulfuric acid gave H2[pz(5 -Me)8], 47 (65%) and remetalation with the anhydrous acetate salts of copper and nickel gave 48 (80%) and 49 (65%). 

Other nucleophile-electrophile pairs for which the pm-disubstituted naphthalene system has been used to monitor potential bonding interactions are illustrated in [35] and [36], The methoxynitrile [35], for example, shows the same sort of evidence for a bonding interaction, marked by a 7° distortion from linearity at the nitrile carbon, in plane, and exactly away from the methoxyl oxygen (Procter et al., 1981) so also does the bipyridyl dinitrile [37] (Baxter et al., 1991). In the unique case of the 8-diazonium quinoline-N-oxide [36] the proximity of a formally negatively charged oxygen induces a distortion from linearity of 10.4° in the diazonium group (Wallis and Dunitz, 1984). 

The aa -bipyridyl (bipy) complexes Sc(bipy)2X3 (X = Cl, NO3, or NC8), and [bipyH]3[Sc(NC8)6] have been isolated in the former group all ligands were bonded directly to the metal atom. Reaction of 8c(02CMe)3 with o-phthalo-dinitrile gave 8cHPc and 8cPc (Pc = phthalocyanine). The former could be easily deprotonated, and treatment of the latter in DMF with alumina and HCl afforded 8cPcCl,H20. 

The chemical transformation must not affect the stereogenic centers. Suitable acyclic candidates are compounds with easily convertible functional groups, such as diols, diamines, amino alcohols, dicarboxylic acids and so on. A number of procedures known before 1973 have been compiled, including conversion of diols and amino alcohols into sulfites or 1,3-dioxolanes by thionyl chloride, or acetalization with ketones31,1"319, as well as the conversions of dinitriles into imides320, dicarboxylic acids into cyclic anhydrides or imides321, and hydroxy acids into oxazolidones 322. 

A crude mixture of enzymes isolated from Rhodococcus sp. is used for selective hydrolysis of aromatic and aliphatic nitriles and dinitriles (117). Nitrilase accepts a wide range of substrates (Table 8). Even though many of them have low solubility in water, such as (88), the yields are in the range of 90%. Carboxylic esters are not susceptible to the hydrolysis by the enzyme so that only the cyano group of (89) is hydrolyzed. This mode of selectivity is opposite to that observed upon the chemical hydrolysis at alkaline pH, esters are more labile than nitriles. Dinitriles (90,91) can be hydrolyzed regioselectively resulting in cyanoacids in 71—91% yield. Hydrolysis of (92) proceeds via the formation of racemic amide which is then hydrolyzed to the acid in 95% ee (118). Prochiral 3-substituted glutaronitriles (93) are hydrolyzed by Phodococcus butanica in up to 71% yield with excellent selectivity (119). 

Dinitriles 97 on treatment with bases gave iminopyrrolizines 98a or aminopyrrolizines 98b.67,68 Imine 98a (R = piperidyl) formed a salt (99) with methyl iodide or with Meerwein s salt. Substitution of the dimethylamino group to give derivatives 100 is easily achieved67 (see Section III). 

When dinitrile 19 was subjected to Pinner reaction conditions, and the imidate was then hydrolyzed, the desired 7 was obtained quantitatively and as a single diastereomer (Scheme 7). Only the equatorial CN group of 19 underwent the Pinner reaction the axial CN group remained complete-... 

Some organic strong bases SM in CH3OH (see Examples 1 and 10), 1,8-diazabicyclo[5.4.0]undece-7-ene 933 (DBU, Example 10), l,5-diazabicyclo[4.3.0] non-5-ene 934 (DBN) are used to perform a nucleophilic attack in the carbon atom (CN group) of PN. Various dinitriles were reacted in the presence of these and other bases 2-N,N-dimethylaminoethanol (DMAE), 1,2,3,6-tetrahydropyridine (THP), triethylamine (TEA), pyridine (Py), triphenylphosphine (TPP), 1,5,7-triaza-bicyclo[4.4.0]dec-5-en 935 (TBD), and 2-/-butylimino-2-diethylamino-l,3-dimethyl-perhydro-l,3,2-diazophosphorine 936 (BEMP) in bulk or in high-boiling solvent [19,29] ... 

Since an important feature of Biicherer-Bergs hydantoin formation is that the process can only work for a-aminonitriles without substituent on the amino group, it follows that one compound of the equilibrium mixture formed from an aldehyde, ammonia, and cyanide is selectively reacted through an irreversible process leaving N-alkylated aminonitriles or imino-dinitriles unreacted. However, the difficulty with this process is that CAAs and hydantoins are poorly reactive towards hydrolysis and need long periods of time to be converted into free AAs. But, CAAs may also have per se a prebi-otic importance in activation pathways towards polypeptides (see Sect. 3.3.7). CAAs can also be synthesized by reaction of free amino acids with cyanic acid/cyanate (a likely prebiotic compound [50]). In the presence of a steady-state concentration of either cyanate or urea in aqueous medium, CAAs are at equilibrium with A A [51]. 

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