Asymmetric Michael Addition of <i>N</i>-<i>tert</i>-Butanesulfinyl Imidate with α,β-Unsaturated Diesters: Scope and Application to the Synthesis of Indanone Derivatives
作者:Jinfang Wang、Yu Zhou、Lei Zhang、Zeng Li、Xianjie Chen、Hong Liu
DOI:10.1021/ol400277h
日期:2013.4.5
An additive-free and highly diastereoselective Michaeladdition reaction of an N-tert-butanesulfinyl imidate to α,β-unsaturated diesters has been developed using LDA as a base with good to excellent yields. The utility of this chemistry is further demonstrated by the asymmetric synthesis of 3-substituted indanone derivatives 8a, 8d, 8e, and 8i with high enantiomeric excess, which are potential building
Mannich-Type Reaction of α-Sulfanyl <i>N</i>-<i>tert</i>-Butanesulfinylimidates: Diastereoselective Access to α-Mercapto-β-amino Acid Derivatives
作者:Jie Feng、Hui Liu、Yun Yao、Chong-Dao Lu
DOI:10.1021/acs.joc.0c02583
日期:2021.2.5
were synthesized diastereoselectively in good yields through the aza-enolization of α-sulfanyl N-tert-butanesulfinylimidates, followed by their nucleophilic addition to N-tosyl imines via a Mannich-typereaction. The resulting derivatives bearing a β-sulfonylamino sulfide moiety participated in further inter- and intramolecular transformations involving episulfonium ion intermediates generated through
Total syntheses of (−)‐isoschizogamine and (−)‐2‐hydroxyisoschizogamine are described. The synthesis employs two asymmetric Michael additions to establish chiral centers at C7 and the quaternary carbon C20. Regioselective reduction of the methylthioiminium cation rather than the enamine generates an isoschizogamine‐type pentacyclic skeleton. Acidic hydrolysis of the isoschizogamine‐type intermediate
An asymmetric synthetic approach to the octahydrofuro[3,4-b]pyridine framework of marine naturalproduct zamamiphidin A has been described. The key steps include an asymmetric Michael addition of (R)-N-tert-butanesulfinyl imidate with enamidomalonate to install the C10 stereocenter, an intramolecular alkoxide exchange/Michael addition/hydrogenation sequence to construct the bicyclic ring system.
已经描述了海洋天然产物zamamiphidin A的八氢呋喃[3,4- b ]吡啶骨架的不对称合成方法。关键步骤包括( R ) -N-叔丁亚磺酰基亚氨酸酯与烯胺丙二酸酯的不对称迈克尔加成以安装C10立体中心,分子内醇盐交换/迈克尔加成/氢化序列以构建双环系统。
Aldol Reaction of <i>N</i>-<i>tert</i>-Butanesulfinyl Imidates under Basic Conditions for Diastereoselective Synthesis of <i>anti</i>-Aldols
作者:Chun-Tian Li、Hui Liu、Yan-Jun Xu、Chong-Dao Lu
DOI:10.1021/acs.joc.7b01982
日期:2017.10.20
Diastereoselectivealdolreaction of N-tert-butanesulfinyl imidates under typical hard enolization conditions is reported. Potassium bis(trimethylsilyl)amide (KHMDS) effectively promotes the aldolreaction of α-aryl- and α-alkyl-substituted imidates, providing anti-aldol adducts in high yields with good to excellent diastereoselectivities. In the case of α-aryl imidates, high conversion depends on