Synthesis of Dithia[5]helicenes and Enantioselective Synthesis of Helically Chiral Thia[6]helicenes via Rh-Catalyzed Intramolecular [2 + 2 + 2] Cycloaddition of Triynes
作者:Shun Nishibe、Taichi Kishi、Mamoru Ito、Takanori Shibata
DOI:10.1021/acs.joc.2c02466
日期:——
synthesized in high yields via a cationic Rh-catalyzed intramolecular [2 + 2 + 2] cycloaddition of triynes bearing sulfur-containing 1,6-diynes. Thia[6]helicene could be obtained with a high enantiomeric excess of P-isomers by using (S)-SEGPHOS as a chiral ligand. This protocol is the first example of the synthesis of thiahelicenes via [2 + 2 + 2] cycloaddition and can also be used for the asymmetric construction
通过阳离子 Rh 催化的含硫 1,6-二炔三炔的分子内 [2 + 2 + 2] 环加成反应,高产率合成了二硫杂[5]螺烯和螺旋手性硫杂[6]螺烯。通过使用( S )-SEGPHOS作为手性配体,可以获得具有高对映体过量P-异构体的硫杂[6]螺旋烯。该方案是通过[2 + 2 + 2]环加成合成硫代螺旋烯的第一个例子,也可用于氮杂[6]螺旋骨架的不对称构建。