Allylic acylation

Isoquinoline also undergoes this simultaneous allylation-acylation to afford 1,2-adducts that can undergo Diels-Alder cyclization (equation I).1... 

The group R1 can be allyl, acyl, or alkynyl, and arynes can also act as the acceptors. The catalysts are usually Ni(cod)2, or ligated palladium. The mechanisms are not understood in detail, but a catalytic cycle involving the product of oxidative addition, Sn-M-R1, is thought to be involved. The stannylalkenes that are formed can then be subjected to reaction with electrophiles (e.g., AczO or RCH=0), or to coupling reactions in the presence of transition metals (e.g., the Stille reaction). 

The osmiophilic behavior of allylic acyl groups in rigid cyclohexenes has also been observed 94c. 

The reverse regiochemistry in additions to 43 was accomplished with cuprate nucleophiles. Thus 506, the regioisomer of 496, could be obtained in good yield as shown (examples include R = Me, Bu, Ph E = H, allyl, acyl). 

Shirakawa, E. et al., Nickel-catalyzed carbostannylation of alkynes with allyl-, acyl-, and aUcynylstan-nanes Stereoselective synthesis of trisubstituted vinylstannanes, J. Am. Chem. Soc., 121, 9907, 1999. Matsukawa, Y. et al., Lewis acid catalyzed allylstannylation of unactivated alkynes. Tetrahedron, 155, 3779, 1999. 

In fact, the very first report on the preparation of L-PEI was based on the hydrolysis of PAOx and it appears that any PAOx, including the rather stable poly(2-phenyl-2-oxazoline), may be converted into L-PEI. ° The side chain does however effect the hydrolysis rate, with the lower allyl acyls being hydrolysed much more rapidly than the higher allq l or aryl acyl groups. Owing to the commercial availability of the monomers and relative ease of PAOx synthesis, the hydrolysis of PAOx is the most common route to L-PEI, and two commercial suppliers of L-PEI also employ this route. 

Aliphatic Friedel-Crafts ketone synthesis Allylic acylation... 

Allylic acylation under Friedel-Crafts conditions has been reported Perchloric acid has been recommended as a catalyst for various 0-acylations such as enol lactonization and enol acetylation of steroids... 

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