Allyl chloride, 2- reaction with silver perchlorate

Trimethylsiloxy)allyl cations (5 Y = OSiMea) are obtained by the reaction of 2-(trimethylsi-loxy)allyl chlorides (4 X = Cl, Y = OSiMea) with silver perchlorate in nitromethane (Scheme 2). lliese intermediates are also obtained with the aid of a Lewis acid. It has been reported that 2-siloxyacrolein (12a R = H), but not the less electrophilic (12b R = Me), when activated by an equimolar amount of SnCl4 serves as a l-hydroxy-2-oxidoallyl synthon (13) (Scheme 5). ... 

Cycloadditions. Silver perchlorate converts the l,l-dimcthyl-2-(tri-methylsiloxy)allyl chloride (1) and related allylic chlorides into an oxyallyl cation (a), which reacts with 1,3-dienes to form seven-membered ketones, often in high yield, particularly in reactions conducted in nitromethane. 

Abstraction of chloride from a vinylpalladium complex by silver acetate has been reported,45 as well as halide abstraction by silver triflate from arylpalladium halides.46 More interestingly in the context of creating C-C bonds, silver perchlorate was able to promote the reaction of (r -aryl)palladium bromide with dienes. Silver-promoted bromide abstraction led to the formation of (r 1-r 2-enyl)palladium complexes, which evolved further through the regioselective formation of a C-C bond between the aryl group and the former diene. Reactions with nonconjugated dienes suggested that the reaction proceeds via carbometallation of the less crowded double bond. Isomerization and (3 elimination led to a (ri3-allyl)palladium complex (Scheme 10.26).47... 

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