Isomerisation of prop-2-ynylic esters into 1,2- and 1,3-dienyl esters

Sigmatropic Rearrangements and Related Processes Promoted by Silver

“…53 Interestingly, these authors 53 and later others 54 showed the importance of the silver counterion in such rearrangements. 53 Interestingly, these authors 53 and later others 54 showed the importance of the silver counterion in such rearrangements.…”

Gold-Catalyzed Reaction of Propargylic Carboxylates via an Initial 3,3-Rearrangement

“…Gagosz reported an efficient synthesis of bicyclo-[3.1.0]hexenes and cycloalkenones from propargylic acetates with a tethered C-C double bond (Equation 16). 9b In the proposed mechanism, the cyclization step occurs via the alkene attacking the g-position of the activated carboxyallene.…”

“…The ability of gold complexes to catalyze 3,3-rearrangements comes with no surprise, however. It has been well established in the literature that salts/complexes of other coinage metals (i.e., Ag 15 and Cu 16 ) as well as Pt 17 can catalyze this transformation. Surprisingly, however, only a few synthetic applications 15d,e,16,17a of this transformation had been reported before our study although carboxyallenes are densely functionalized and should be synthetically versatile.…”

Synthesizing Allenes Today (1982-2006)

“…The metal-catalyzed formal [3,3]-sigmatropic rearrangement is a powerful method for the construction of allenyl esters. This transformation has been successfully carried out with silver, 58 gold, 59,60 platinum, 61 and copper 62,63 catalysts. A recent example of this protocol 64 is shown in Scheme 21, where propargyl ester 61 undergoes a gold(I)catalyzed [3,3]-rearrangement when reacted with 10 mol% of gold(III) chloride.…”