Metal-Templated Macrolactamization of Triamino and Tetramino Esters. Facile Synthesis of Macrocyclic Spermidine and Spermine Alkaloids, (<i>S</i>)-(+)-Dihydroperiphylline, (±)-Buchnerine, (±)-Verbacine, (±)-Verbaskine, and (±)-Verbascenine
The totalsynthesis of spermidine and spermine alkaloids, (S)-(+)-dihydroperiphylline (1), (±)-buchnerine (2), (±)-verbacine (3), (±)-verbaskine (4), and (±)-verbascenine (5), is described. The construction of macrocyclic lactams has been efficiently accomplished by the metal-templated cyclization of triamino esters and tetraamino esters. It was also found that the antimony(III) ethoxide is useful
3,5-Bis(perfluorodecyl)phenylboronic acid has been synthesized based on the direct coupling of perfluorodecyl iodide with 1,3-diiodobenzene. This new boronic acid is shown to be a "green" catalyst for the direct amide condensation reaction by virtue of the strong electron-withdrawing effect and the immobility in the fluorous recyclable phase of the perfluorodecyl group.