54345-13-0Relevant academic research and scientific papers
Efficient synthesis of 4-(2′-alkenyl)-2,5-dihydrofurans and 5,6-dihydro-2H-pyrans via the Pd-catalyzed cyclizative coupling reaction of 2,3- or 3,4-allenols with allylic halides
Ma, Shengming,Gao, Wenzhong
, p. 6104 - 6112 (2007/10/03)
In the absence of a base, palladium(II) catalysts, such as PdCl2, PdCl2(CH3CN)2, Pd(OAc)2, and [(π-C3H5)PdCl]2, can catalyze the cyclizative coupling reaction of 2,3- or 3,4-allenols with allylic halides in DMA at room temperature to provide 2,5-dihydrofurans and 5,6-dihydro-2H-pyrans, respectively, in moderate to good yields. Under similar reaction conditions, nonsubstituted 2,3-allenol 1s affords bimolecular cyclizative coupling product 5s as the major product. The scope of the reaction and its mechanism have been studied briefly. On the basis of the experimental results, the transformation was believed to proceed via a divalent palladium-catalyzed pathway.
SYNTHESE D'ALCOHOLS α-ALLENIQUES PAR REACTION D'ORGANOCHROMIQUES PROPARGYLIQUES SUR LES ALDEHYDES ET LES CETONES
Place, Pierre,Verniere, Catherine,Gore, Jacques
, p. 1359 - 1368 (2007/10/02)
Propargylic bromides can be condensed with aldehydes and ketones in the presence of Hiyama's reagent (2CrCl3+LiAlH4 in THF) leading to α-allenic alcohols, to homopropargylic alcohols or to the mixture of both of them.The selectivity (or specificity) of this reaction depends on the substitution of the propargylic bromide, on the structure of the ketone, and on the presence of HMPT in the reaction mixture.In many cases, α- allenic alcohol has been specifically or very selectively obtained.The mechanism of the reaction and the influence of the various parameters are discussed.
