Acyl derivatives of 5-phenylpent-4-enylamine were cyclized to give 2-substituted 3-benzal-3,4,5,6,-tetrahydropyridines in good yield. This is a new synthesis of pyridine derivatives.
Thioacetals are selectively transformed into two types of terminal olefins, one with one-carbon homologation and the other with two-carbon homologation, by treatment with a titanocene(II) species under ethylene. The mode of the reaction is controlled by changing the ligands coordinated to titanocene(II).
Decarboxylative Allylation using Sulfones as Surrogates of Alkanes
作者:Jimmie D. Weaver、Jon A. Tunge
DOI:10.1021/ol801951e
日期:2008.10.16
alpha-Sulfonyl functional groups are traceless activating groups that facilitate catalytic decarboxylative allylations in high yield yet can be cleaved to allow the synthesis of simple allylated alkanes. Substrate studies suggest that decarboxylation to form an a-sulfonyl anion is rate-limiting. Furthermore, the anion is formed reglospecifically under formally neutral conditions.
Cyclopropanes were obtained by the titanocene(II)-promoted reaction of thioacetals with vinyl pivalate. It was also found that vinycyclopropanes were produced by a similar treatment of thioacetals with the titanocene(II) species in the presence of 1,3-dienes. (C) 2004 Elsevier Ltd. All rights reserved.