Ir/Zn-cocatalyzed chemo- and atroposelective [2+2+2] cycloaddition for construction of CN axially chiral indoles and pyrroles

作者：Yang, Jian; Xie, Zhong-Yang; Ye, Yu-Jie; Ye, Sheng-Bing; Wang, Yi-Bo; Wang, Wen-Tao; Qian, Peng-Cheng^*; Song, Ren-Jie; Sun, Qing^*; Ye, Long-Wu^*; Li, Long

来源：Science Advances, 2023, 9(51): eadk1704.

DOI：10.1126/sciadv.adk1704

• ENANTIOSELECTIVE SYNTHESIS
• ASYMMETRIC-SYNTHESIS
• YNAMIDES
• DIYNES

Here, an Ir/Zn-cocatalyzed atroposelective [2+2+2] cycloaddition of 1,6-diynes and ynamines was developed, forging various functionalized C -N axially chiral indoles and pyrroles in generally good to excellent yields (up to 99%), excellent chemoselectivities, and high enantioselectivities (up to 98% enantiomeric excess) with wide substrate scope. This cocatalyzed strategy not only provided an alternative promising and reliableway for asymmetric alkyne [2+2+2] cyclotrimerization in an easy handle but also settled the issues of previous [Rh(COD)2]BF4catalyzed system on the construction of C -N axial chirality such as complex operations, limited substrate scope, and low efficiency. In addition, control experiments and theoretical calculations disclosed that Zn(OTf) 2 markedly reduced the barrier of migration insertion to significantly increase reaction efficiency, which was distinctly different from previous work on the Lewis acid for improving reaction yield through accelerating oxidative addition and reductive elimination..

• 单位
  南昌航空大学; 厦门大学