Helicene synthesis by Brønsted acid-catalyzed cycloaromatization in HFIP [(CF<sub>3</sub>)<sub>2</sub>CHOH]
作者:Takeshi Fujita、Noriaki Shoji、Nao Yoshikawa、Junji Ichikawa
DOI:10.3762/bjoc.17.35
日期:——
A facile synthesis of carbo- and heterohelicenes was achieved via tandem cycloaromatization of bisacetal precursors, which were readily prepared through C–C bond formation by Suzuki–Miyaura coupling. This cyclization was efficiently realized by a catalytic amount of trifluoromethanesulfonic acid (TfOH) in a cation-stabilizing solvent, 1,1,1,3,3,3-hexafluoropropan-2-ol (HFIP), which readily allowed
通过双缩醛前体的串联环芳构化,可以轻松实现碳-和异戊烯酮的合成,双缩醛前体很容易通过Suzuki-Miyaura偶联通过C-C键形成而制备。通过在阳离子稳定溶剂1,1,1,3,3,3-六氟丙烷-2-醇(HFIP)中催化量的三氟甲磺酸(TfOH)可以有效地实现克级合成,可以有效地实现这种环化高阶螺旋螺旋,双螺旋螺旋螺旋和杂螺旋螺旋。