3-Chloroacrylonitrile, nucleophilic

On the other hand, some evidence for the longer life-time of the intermediate formed with amines may be inferred from the formation of small amounts of (116a) from piperidine and /J-chloroacrylonitrile, in addition to the main substitution product. (116a) is also the sole substitution product with aniline (R1=Ph, R2 = H) but no such products were reported for reactions with oxygen or sulphur nucleophiles. For formation of (116a) the initially-formed carbanion should be long-lived enough as to attack another j8-chloroacrylonitrile molecule (Scotti and Frazza, 1964). 

Poly(a-chloroacrylonitrile) decomposes to low molecular weight compounds when treated with nucleophiles [A,iV-diethyldithiocarbamate (Et2NCS2 ), PhS and azide ions]. An2 SRN mechanism was suggested for this reaction, in which an ET to the polymer leads to a radical and chloride ion. Coupling with the nucleophile and decomposition are the main reactions proposed for the radical intermediates98. The reaction of 2-chloro-2-methylpropionitrile, as a model compound, with TV, A-diethyldithiocarbamate (52% yield) and PhS (61% yield) was studied98. 

Methyl 2-haloacrylate and 2-chloroacrylonitrile (84,187) react with triethyl phosphite to give the 3-phosphonates rather than the 2-phos-phonates. Nucleophilic attack by phosphite in the beta position of Michael acceptors in general and acrylate esters in particular has been " established recently for many compounds (cf. Section V-C-2). Coover, McCall, and Dickey postulate that the intermediate thus formed stabi-... 

Nevertheless, the use of relative reactivities to characterize carbenic philicity is restrictive the apparent philicity is related to the alkenes selected for the relative reactivity measurements. What if the set of alkenes were expanded by the addition of an even more electron-deficient alkene Such a test was applied in 1987 [65], using a-chloroacrylonitrile, 26, which is more 7t-electron deficient than acrylonitrile, 27. We found that PhCF or PhCCl added 15 or 13 times, respectively, more rapidly to 26 than to 27. In preferring the more electron-deficient olefin, the carbenes exhibited nucleophilic character. However, because they also behave as electrophiles toward other alkenes (Table 4), they must in reality be ambiphiles. In fact, we now realize that all carbenes have the potential for nucleophilic reactions with olefins the crucial factor is whether the carbene s filled a orbital (HOMO)/alkene vacant Ji orbital (LUMO) interaction is stronger than the carbene s vacant p orbital (LUMO)/aIkene filled k orbital (HOMO) interaction in the transition state of the addition reaction. [63]... 

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