Silver-Catalyzed Cascade Cyclization/1,6-Conjugate Addition of Homopropargyl Sulfonamides to <i>p</i>-Quinone Methides: An Approach to Diverse 3-Diarylmethine Substituted Dihydropyrroles
作者:Sachin R. Shirsath、Ganesh S. Ghotekar、Vir Bahadur、Rajesh G. Gonnade、M. Muthukrishnan
DOI:10.1021/acs.joc.0c01922
日期:2020.12.4
disclosed. The reaction pathway involves an intramolecular cascade cyclization of homopropargyl sulfonamides to generate a highly reactive dihydropyrrole intermediate in situ followed by conjugate addition with p-quinone methides. This method provides an efficient and scalable route for the synthesis of 3-diarylmethine substituted dihydropyrroles, in onepot.
Stereospecific Synthesis of <i>cis</i>-2,5-Disubstituted Pyrrolidines via <i>N</i>,<i>O</i>-Acetals Formed by Hydroamination Cyclization–Hydroalkoxylation of Homopropargylic Sulfonamides in HFIP
作者:Weilin Wang、Xiaohui Cao、Weiguo Xiao、Xiaoyu Shi、Xiaodan Zuo、Lingyan Liu、Weixing Chang、Jing Li
DOI:10.1021/acs.joc.0c00403
日期:2020.6.5
5-cis-disubstituted pyrrolidines with high diastereoselectivity (up to >99:1 dr) and enantioselectivity (up to >99% ee). The overall reaction constitutes a formal 1,1-bifunctionalization of terminal alkynes, which has hitherto been reported only rarely. Additionally, this method provides efficient access to pharmaceutical intermediate and to carry out postmodification of natural products.
A novel hypervalent iodine-triggered hydroamination of homopropargyl sulfonamides with copper halides to obtain dihalo-2,3-dihydropyrroles was efficiently developed.