The reactions of styrene and phenylacetylene toward charged electrophiles have been studied in the gas phase by a radiolytic technique, supported by chemical ionization mass spectrometry. The two substrates undergo a methylation reaction by Me2F+ both at the ring and at the side chain, at variance with the side-chain electrophilic attack prevailing in condensed phase. The nitrating (MeONO2)H+ ion selectively nitrates the ortho position of styrene, an unprecedented ring nitration on this substrate. The formation of neutral isomeric products is determined by the efficiency of deprotonation of their ionic precursors and is sensitive inter alia to the presence of oxygen nucleophiles. The overall reactivity pattern is rationalized in terms of preferential electrostatic interactions between the reactants in a preliminary collision complex, whereby an incoming
GAS-PHASE REACTIONS OF CHARGED ELECTROPHILES WITH STYRENE AND PHENYLACETYLENE / Crestoni, Maria Elisa; Fornarini, Simonetta. - In: JOURNAL OF THE AMERICAN CHEMICAL SOCIETY. - ISSN 0002-7863. - STAMPA. - 111:16(1989), pp. 6008-6014. [10.1021/ja00198a006]
GAS-PHASE REACTIONS OF CHARGED ELECTROPHILES WITH STYRENE AND PHENYLACETYLENE
CRESTONI, Maria Elisa;FORNARINI, Simonetta
1989
Abstract
The reactions of styrene and phenylacetylene toward charged electrophiles have been studied in the gas phase by a radiolytic technique, supported by chemical ionization mass spectrometry. The two substrates undergo a methylation reaction by Me2F+ both at the ring and at the side chain, at variance with the side-chain electrophilic attack prevailing in condensed phase. The nitrating (MeONO2)H+ ion selectively nitrates the ortho position of styrene, an unprecedented ring nitration on this substrate. The formation of neutral isomeric products is determined by the efficiency of deprotonation of their ionic precursors and is sensitive inter alia to the presence of oxygen nucleophiles. The overall reactivity pattern is rationalized in terms of preferential electrostatic interactions between the reactants in a preliminary collision complex, whereby an incomingI documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
