Regio- and Stereoselective Isomerizations of Allenamides: Synthesis of 2-Amido-Dienes and Their Tandem Isomerization-Electrocyclic Ring-Closure
作者:Ryuji Hayashi、Richard P. Hsung、John B. Feltenberger、Andrew G. Lohse
DOI:10.1021/ol900647s
日期:2009.5.21
A regio- and stereoselectiveisomerization of allenamides is described, leading to preparations of de novo 2-amido-dienes and a tandem isomerization-6π-electron electrocyclic ring-closure.
An efficient and practical entry to 2-amido-dienes and 3-amido-trienes from allenamides through stereoselective 1,3-hydrogen shifts
作者:Ryuji Hayashi、John B Feltenberger、Andrew G Lohse、Mary C Walton、Richard P Hsung
DOI:10.3762/bjoc.7.53
日期:——
by the use of Bronsted acids. Under either condition, these processes are highly regioselective in favour of the alpha-position, and highly stereoselective in favour of the E-configuration. In addition, 6pi-electron electrocyclic ring-closure could be carried out with 3-amido-trienes to afford cyclic 2-amido-dienes, and such electrocyclic ring-closure could be rendered in tandem with the 1,3-hydrogen
描述了通过烯丙酰胺的 1,3-氢转移制备从头无环 2-酰胺二烯和 3-酰胺三烯。这些 1,3-氢转移可以通过热实现,也可以通过使用布朗斯台德酸来促进。在任一条件下,这些过程都具有高度区域选择性,有利于 alpha 位置,并且具有高度立体选择性,有利于 E 构型。此外,3-酰氨基三烯可以进行6pi-电子电环闭环,得到环状2-酰氨基二烯,并且这种电环闭环可以与1,3-氢位移同时发生。