Cyanoolefins

Tetrafluoroethene hexamer reacts with ammonia to give a nitrile. The reaction occurs probably by initial formation of a very reactive cyanoolefin [95] (equation 81). 

Equilibrium Constants for Cyanoolefin Reactions 1 with Ni[P(0-b-iolyl)3]3 in Benzene at 25°C... 

Studies of equilibria in which cyanoolefins are allowed to react with Ni[P(0-o-tolyl)3]3 have shown (36) that olefin coordination of 4PN is preferred over 3PN by a factor of 200, while olefin coordination of 2PN is preferred over 3PN by a factor of 1000. (Note the decreasing K for olefin complex formation in Table II in the series CH2=CH(CH2)BCN as n increases from 0 to 3 4 x 104,10,3.6, and 2.2. A value of 0.5 can be estimated for n - oo, based on the K for 1-hexene.) The relative amount of nitrile-coordinated nickel in solutions of cyanoolefins increases with added free phosphorus ligand, because of the different stoichiometries in Eqs. (14) and (15). 

Cyanoolefins Hydrocyanated in Unpromoted Reactions Using Ni[P(0-o-tolyl) ]3... 

Isoxazolo[3,4-c/]pyrimidine 39 when treated with cyanoolefins 40, in the presence of TEA as catalyst, gave biologically interesting pyrido[2,3-c/]pyrimidine oxides 41 in excellent yields. Probably, a [4+2] cycloaddition of the azadiene moiety of 39 with keteneimine intermediates, derived from 40 and TEA, is involved in the process <03TL1847>. 

Strongly electrophilic cyanoolefins, such as arylidenemalononitrile, ar-ylidene-cyanoacetate, and arylidenecyanoacetamide react as C, reagents... 

Non-conjugated cyanoolefins are hydrocyanated in the presence of tetrakis(tri-p-tolyl phosphite)nickel(O) at 25 °C. Characteristic in this reaction is the relative stability of the RNiL CN intermediates which allows spectroscopic observation of these species either by NMR or IR. The ratio of linear/branched products in the unpromoted reaction is strongly dependent upon the bulkiness of tbe substrate [15] (Table 3). 

Table 3. Unpromoted hydrocyanation of cyanoolefins using Ni[P(0-o-toIyl)3]4. Olefin Product Ratio N/B ...

Photolysis of cyanoolefin complexes leads to reactions of the olefinic ligand ... 

Baddely has studied the reactions of tetracyanoethylene and other cyano-substituted ethylenes with Ir(I) complexes and found the stabilities of IrX(CO)(P )3) (cyanoolefin) (where X = Cl) from melting points, preparative data and solution behaviour decrease in the order... 

Knoevenagel condensation between the aldehyde (1) and malononitrile (16) to form cyanoolefins (40), followed by a Michael addition with amidine (38), cycloaddition, isomerization, and aromatization to afford the 4-amino-5-pyrimidinecarbonitriles (39) (Figure 9.2). 

Lehn and coworkers reported a series of reactive diene and pentafulvenes involving reversible Diels-Alder reactions at ambient temperature. The results provide a foundation for the implementation of the reversible Diels-Alder reaction in constitutional dynamic chemistry (Scheme 7.26) [27]. With variation of the functionalized substituted fulvenes 108 and cyanoolefin esters 109, the methodology may be applied for the preparation of dynamic combinatorial libraries and provides an entry to reversible dynamic polymers and the discovery of biologically active substances. 

Reaction of [Cp RhCl2]2 with (2,6-dimethoxyphenyl)diphenylphosphine (mdmpp) gave Cp RhCl2(mdmpp-/ ) and Cp"RhCl(mdmpp-P,0), depending on the reaction conditions. Treatment of the first compound with NaPF formed the O-coordinated complex, [Cp"RhCl(mdmpp-P,OMe)](PF6)." Complex Cp"RhCl(mdmpp-P,0) readily reacted with tetracyanoethylene (tcne) or 7,7,8,8,-tetracyano-p-quinomethane (tcnq) to form the 1 1 adducts Cp RhCl(mdmpp-P,0)(tcne) 187 and Cp RhCl(mdmpp-P,0)(tcnq) derived from insertion of cyanoolefins into the... 

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