Copper‐Catalyzed Enantioselective Construction of Tertiary Propargylic Sulfones
作者:José Enrique Gómez、Àlex Cristòfol、Arjan W. Kleij
DOI:10.1002/anie.201814242
日期:2019.3.18
asymmetric synthesis approach has been developed. We disclose a versatile copper‐catalyzed sulfonylation of propargylic cyclic carbonates using sodium sulfinates that allows the construction of propargylic sulfones featuring elusive quaternary stereocenters. This method provides the first successful example of such an enantioselective propargylic sulfonylation, features high asymmetric induction, wide functional
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
Synthesis of pyranopyrazoles with a chiral quaternary carbon stereocenter <i>via</i> copper-catalyzed enantioselective [3 + 3] cycloaddition
作者:Meihui Wang、Bo Li、Baihui Gong、Hequan Yao、Aijun Lin
DOI:10.1039/d1cc07058d
日期:——
A copper-catalyzed enantioselective [3 + 3] cycloaddition of propargyl carbonates and pyrazolones has been disclosed. This reaction provided an efficient route to synthesize pyranopyrazoles containing a chiral quaternary carbon stereocenter in good yields with good to excellent enantioselectivities. In addition, the hydroxyl group in the products could be conveniently transformed into a variety of
Copper-Catalyzed Enantioselective Synthesis of β-Amino Alcohols Featuring Tetrasubstituted Tertiary Carbons
作者:Lan Tian、Liang Gong、Xia Zhang
DOI:10.1002/adsc.201701613
日期:2018.5.16
Here we report a copper‐catalyzed asymmetric propargylic substitution reaction to prepare tetrasubstituted β‐amino‐β‐ethynyl alcohols in high yields and with enantiomeric ratio (er) up to 94:6. This transformation generates tetrasubstituted tertiary carbons by utilizing stable cyclic carbonates and amines as substrates, economical copper catalysts, and easily accessible ligands.
Enantioselective construction of vicinal tetrasubstituted carbon stereocenters is a formidable challenge in organic synthesis. A copper-catalyzed asymmetric decarboxylative propargylic substitution with 3-amino oxindoles as trisubstituted carbon nucleophiles and propargylic cyclic carbonates as tertiary carbon electrophiles was developed. A range of 3-amino-3,3′-disubstituted oxindoles bearing vicinal quaternary-tetrasubstituted
邻位四取代碳立体中心的对映选择性构建是有机合成中的一项艰巨挑战。开发了一种铜催化的不对称脱羧炔丙基取代,其中 3-氨基羟吲哚作为三取代碳亲核试剂,炔丙基环状碳酸酯作为叔碳亲电试剂。以高产率和良好的立体选择性(高达 98% 的产率,>20:1 dr 和 98.5:1.5 er)获得了一系列带有连位季四取代碳立体中心的 3-氨基-3,3'-二取代羟吲哚.