Palladium(II)-catalyzed claisen rearrangement of allyl vinyl ethers

✍ Scribed by J.L van der Baan; F Bickelhaupt

• Publisher: Elsevier Science
• Year: 1986
• Tongue: French
• Weight: 258 KB
• Volume: 27
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(00)85449-0

✦ Synopsis

The Claisen rearrangement of ally1 vinyl ethers is catalyzed by PdCQ(CH3CN)Z. provided that alkyl substituents protect the vinyl ether double bond from coordination by the metal catalyst. [3,3]Sigmatropic rearrangements are very useful for the formation of C-C, C-O, C-N and C-S bonds. Besides the classical thermal version of the reaction, use is made increasingly of transition metal catalysis, especially by Hg(II)-and Pd(II)-salts, which enable the execution of many of these rearrangements under mild conditions, in high yield, and with high regio-and stereoselectivity. Examples are the Pd(II)-catalyzed Cope rearrangement of 1,5-dienes, 1) and the Hq(II)-or Pd(II)-catalyzed hetero-Cope rearrangements of allylic esters, 2) ally1 imidates, 3) and S-ally1 thioimidates. 4) These reactions are suggested 1,2) to proceed z&z a "cyclization-induced rearrangement" pathway, which accounts

for the action of the metal catalysts (eq. ( 1)).