Application of phase-transfer catalysis (PTC) to reactions of C-H acids with chloroethylenes

Abstract

2-Phenylalkanenitriles 1 react under PTC conditions with 1,1-or cis-dichloroethylene giving ethynylated products 2. Nitriles 1, α-substituted desoxybenzoines 6, 2-substituted phenylacetaldehydes 8, 1,3-dialkylindene 10 and substituted diethylmalonates 12 afford with trichloroethylene 1,2-dichlorovinylated derivatives, respectively 3, 7, enol ethers 9, 11 and 13. PTC reaction of trans-dichloroethylene with 1 or 10 lead to formation of 2-chlorovinylated 14 or ethynylated 16 products, respectively. In majority of cases the products were formed in good yield. The course of these reactions is rationalized.

Kinetics of the Reaction between 2-Phenylpropionitrile and 2-Chloro-5-nitrotrifluoromethylbenzene under Phase-Transfer Catalysis

“…The reactivity of in situ generated anionic nucleophiles under PTC conditions is usually enhanced since they result unsolvated and therefore strongly activated for the substitution reactions. ,, The reaction of carbanions with haloaromatic compounds offers important synthetic possibilities as it provides a way to introduce a carbon skeleton in an aromatic ring, which is often accompanied by the introduction or change in functionality. , The reactions of α-phenyl alkylacetonitriles with chloronitrobenzenes were reported to proceed with yields ranging from 59 to 92%. ,, An interfacial mechanism, which involves the carbanion formation by proton abstraction from the CH acid dissolved in a nonpolar solvent by a concentrated aqueous NaOH phase boundary, is usually accepted for this type of reaction. , Thus, in situ generated carbanions are ion-exchanged and extracted to the organic phase as fully lipophilic ion pairs with the PT cation and further reacted with the substrate, even though a mechanistic picture of the way these reactions take place was proposed in the early 1970s . In this work, the kinetics of the reaction between 2-chloro-5-nitrotrifluoromethylbenzene (CNTFB) and 2-phenylpropionitrile anion (HPP - ) under PTC to yield 2-(4-nitro-2-trifluoromethylphenyl)-2-phenylpropionitrile has been studied.…”