Alkylation mechanism of benzene with 1-dodecene catalyzed by Et3NHCl-AlCl3

The isotope exchange method was employed to investigate the catalytic mechanism of ionic liquid in alkylation of benzenes with olefins. It is proposed that alkylation was induced by the Lewis acid AlCl3 which attracted pi electrons of 1-dodecene to shift toward 1-carbon, thus forming a carbonium ion. The carbonium ion further reacted with benzenes to form a complex. Due to unstabilit of the complex, a deuterated ring proton was transferred into an electronegative 1-carbon of the side chain to substitute for the AlCl3, accordingly 2-phenyldodecane was generated.