Metal-catalyzed addition/elimination allylic alcohol

Isomerization of allylic alcohol to ketone has been extensively studied [13], and two different pathways have been established, including tt-allyl metal hydride and the metal hydride addition-elimination mechanisms [5,14]. McGrath and Grubbs [ 15] investigated the ruthenium-catalyzed isomerization of allyl alcohol in water and proposed a modified metal hydride addition-elimination mechanism through an oxygen-functionality-directed Markovnikov addition to the double bond. 

Kondo and Mitsudo are the pioneers of transition-metal-catalyzed retro-allylation [7]. They described this phenomenon as deallylation and fi-allyl elimination . Ruthenium-catalyzed reaction of tertiary homoallylic alcohols proceeds in the presence of allyl acetate under an atmosphere of carbon monoxide in tetrahydro-furan (THF) at a relatively high temperature of 180 C to afford the corresponding ketones (Scheme 5.3). Although the exact roles of allyl acetate and carbon monoxide are not clear, they propose a mechanism involving oxidative addition of the... 

Gabriele et al. reported a sequential homobimetallic palladium-catalyzed cascade reaction for the synthesis of benzofuran derivatives 207 [80] (Scheme 6.57). Sequential homobimetallic catalysis is different in catalytic cycles promoted by the same metal but in different oxidation states. After oxidative addition and oxopalladation, 5-exo-dig cyclization occurs, followed by carbonylation, affording the intermediate 206. The allylic alcohol is reduced by H—Pd—I through formation of a ji-aUyl complex and the elimination of water. Finally, the product observed is afforded... 

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