1174672-16-2Relevant academic research and scientific papers
Gold-catalyzed 1,2-/1,2-bis-acetoxy migration of 1,4-bis-propargyl acetates: A mechanistic study
De Haro, Teresa,Gomez-Bengoa, Enrique,Cribiu, Riccardo,Huang, Xiaogen,Nevado, Cristina
experimental part, p. 6811 - 6824 (2012/07/03)
The late transition metal catalyzed rearrangement of propargyl acetates offers an interesting platform for the development of synthetically useful transformations. We have recently shown that gold complexes can catalyze a highly selective tandem 1,2-/1,2-bis-acetoxy migration in 1,4-bis-propargyl acetates to form 2,3-bis-acetoxy-1,3-dienes. In this way, (1Z,3Z)- or (1Z,3E)- and (1E,3Z)-1,3-dienes could be obtained in a stereocontrolled manner depending on the electronic and steric features of the ancillary ligand bound to gold and the substituents at the propargylic positions. In this work, we report an experimental study on the scope of this transformation, plus a detailed theoretical examination of the reaction mechanism, which has revealed the key features responsible for the reaction stereoselectivity. Synthetic applications towards the one-pot synthesis of quinoxaline heterocycles and tandem Diels-Alder processes have also been devised. Copyright
Gold-Catalyzed stereocontrolled synthesis of 2,3-Bis(acetoxy)-1,3-dienes
Huang, Xiaogen,De Haro, Teresa,Nevado, Cristina
supporting information; experimental part, p. 5904 - 5908 (2010/03/03)
A 1,4-bis(propargyl acetates) undergo a highly selective tandem 1,2-/1,2-Bis(acetoxy) migration to give 2,3-Bis(acetoxy)-1,3-dienes, that, depending on the catalyst of choice,(1Z,3Z) or (1Z,3E and 1E,3Z)-1,3-dienes can be obtained in a stereocontrolled manner. It was found that the 1,2-Bis(acetoxy) migration was favored in all studied cases and no allene product was observed in the reaction mixtures. It was also found that more e sterically demanding substrate dramatically improved the selectivity thereby revealing the key role of sterics in the stereocontrol of these transformations. The results show that the choice of the acetoxy migrating first seemed to be of key importance and is determined both by the electronic character and sterical bulkiness of substituents at the propargylic position.
