Direct allenol-based stereocontrolled access to substituted (E)-1,3-enynes
作者:Benito Alcaide、Pedro Almendros、Teresa Martínez del Campo
DOI:10.1039/c2ob26085a
日期:——
A stereoselective synthesis of 1-substituted (E)-2-aryl-but-1-en-3-ynes, including tetrasubstituted alkenes, has been developed from aryl-substituted α-allenols by treatment with the AcCl–NaOH (aqueous) system. This transformation might be explained through the elimination of acetic acid, made up of a δ-hydrogen and the acetate group in the initially formed α-allenic acetate.
Broadening the Scope of the Gold-Catalyzed [2+2] Cycloaddition Reaction: Synthesis of Vinylcyclobutenes and Further Transformations
作者:M. Elena de Orbe、Antonio M. Echavarren
DOI:10.1002/ejoc.201800170
日期:2018.6.15
The synthesis of 1‐vinyl‐, 3‐vinyl‐ and 3‐alkynylcyclobutenes has been achieved by a gold(I)‐catalyzed [2+2] cycloadditionreaction. One‐pot transformations of the versatile cyclobutenes render cyclopentenes, 2,3‐dihydrofurans, polycyclic skeletons and beyond.
We present herein the first oxidation of enynylboronates for the synthesis of γ-lactones, including spiro-, and fused-butanolides as well as butenolides that are prevalent in nature products and bioactive molecules. The asymmetric version of this oxidation was also achieved in the presence of chiral ketone and Oxone. This process successively involves the oxidation of C(sp)−B bond, the epoxidation