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.
Hg/Pt-catalyzed conversion of bromo alkynamines/alkynols to saturated and unsaturated γ-butyrolactams/lactones via intramolecular electrophilic cyclization
Convenient and general Hg(II)/Pt(IV) catalyzed syntheses of γ-butyrolactams and α,β-unsaturated γ-butyrolactones/lactams are described via intramolecular electrophilic cyclizations of bromoalkynes with tosylamino and hydroxyl tethers. The reaction features the use of wet solvents, the exclusion of any base and additive, mild conditions and practical yields. We also synthesised few chiral lactams through
One-pot Preparation of Homopropargylic <i>N</i>-Sulfonylamines Catalyzed by Zinc Powder
作者:Chao Wu、Wangyong Huang、Weimin He、Jiannan Xiang
DOI:10.1246/cl.130626
日期:2013.10.5
A new one-pot method for synthesis of homopropargylic N-sulfonylamines from aldehydes catalyzed by zinc powder is described. The procedure is lauded by its simplicity, good yields, and adaptability to a wide variety of aldehydes.