Brønsted Acid Catalyzed PhSe Transfer versusRadical Aryl Transfer: Linear Codimerization of Styrenes and InternalOlefins.

Brønstedacid p-TsOH·H2O-catalyzedhydrovinylation of styrenes with internal olefins α-oxo ketenedithioacetals was efficiently achieved in the presence of N-phenylselenophthalimide (N-PSP), regioselectivelyaffording Markovnikov phenylselenative hydrovinylation products throughPhSe transfer of the phenylseleno ketene dithioacetal intermediates.Radical reduction of the resultant PhSe-alkyl-substituted ketene dithioacetalswith AIBN/n-Bu3SnH gave the corresponding anti-Markovnikov hydrovinylation products formally fromthe linear codimerization of styrenes and the internal olefins. [ABSTRACT FROM AUTHOR]