Radical Route to 1,4-Benzothiazine Derivatives from 2-Aminobenzenethiols and Ketones under Transition-Metal-Free Conditions
作者:Ya-mei Lin、Guo-ping Lu、Rong-kang Wang、Wen-bin Yi
DOI:10.1021/acs.orglett.6b03324
日期:2016.12.16
Transition-metal-free radical access to 1,4-benzothiazine derivativesfrom o-aminobenzenethiols is disclosed. This procedure is available for various ketones including α,β-unsaturated, cyclic, linear, and fluoroalkyl ketones to generate a number of 1,4-benzothiazines, which exist in numerous bioactive and natural molecules, rendering this protocol attractive to both synthetic and medicinal chemistry
Potassium Base‐Catalyzed Michael Additions of Allylic Alcohols to α,β‐Unsaturated Amides: Scope and Mechanistic Insights
作者:Masahiro Sai、Hiroaki Kurouchi
DOI:10.1002/adsc.202100272
日期:——
We report herein the first KHMDS-catalyzed Michaeladditions of allylic alcohols to α,β-unsaturated amides through allylic isomerization. The reaction proceeds smoothly in the presence of only 5 mol% of KHMDS to afford a variety of 1,5-ketoamides in high yields. Mechanistic investigations, including experimental and computational studies, reveal that the KHMDS-catalyzed in-situ generation of the enolate
Formal Diels–Alder Reactions of Chalcones and Formylcyclopropanes Catalyzed by Chiral N-Heterocyclic Carbenes
作者:Hui Lv、Junming Mo、Xinqiang Fang、Yonggui Robin Chi
DOI:10.1021/ol202250s
日期:2011.10.7
Highly enantioselective (formal) hetero-Diels–Alder reactions between chalcones and formylcyclopropanes are disclosed. The challenging N-heterocycliccarbene (NHC)-bounded enolate intermediates from formylcyclopropanes were captured for new C–C bond forming reactions. The reaction products were obtained with high diastereo- and enantioselectivities and could be easily transformed to optically pure
Non-Heme Manganese Complexes Catalyzed Asymmetric Epoxidation of Olefins by Peracetic Acid and Hydrogen Peroxide
作者:Roman V. Ottenbacher、Konstantin P. Bryliakov、Evgenii P. Talsi
DOI:10.1002/adsc.201100030
日期:2011.4.18
Chiral non‐heme aminopyridine manganese complexes catalyze the enantioselective epoxidation of olefins with peracetic acid or hydrogenperoxide with moderate to high yields and ee valuess up to 89% (peracetic acid, AcOOH) and 84% (hydrogenperoxide, H2O2), performing as many as 1000 turnovers.
手性非血红素氨基吡啶锰配合物以过高的产率催化过氧乙酸或过氧化氢对烯烃的对映选择性环氧化,ee值高达89%(过氧乙酸,AcOOH)和84%(过氧化氢,H 2 O 2),执行多达1000次失误。
Switchable Chemoselective Transfer Hydrogenations of Unsaturated Carbonyls Using Copper(I) N-Donor Thiolate Clusters
作者:Meng-Juan Zhang、Da-Wei Tan、Hong-Xi Li、David James Young、Hui-Fang Wang、Hai-Yan Li、Jian-Ping Lang
DOI:10.1021/acs.joc.7b02676
日期:2018.2.2
Unsaturated alcohols and saturated carbonyls are important chemical, pharmaceutical, and biochemical intermediates. We herein report an efficient transfer hydrogenation protocol in which conversion of unsaturated carbonylcompounds to either unsaturated alcohols or saturated carbonyls was catalyzed by Cu(I) N-donor thiolate clusters along with changing hydrogen source (isopropanol or butanol) and base
不饱和醇和饱和羰基是重要的化学,制药和生化中间体。我们在本文中报告了一种有效的转移氢化方案,其中不饱和羰基化合物转化为不饱和醇或饱和羰基的反应是由Cu(I)N供体硫醇盐簇以及变化的氢源(异丙醇或丁醇)和碱(NaOH或K)催化的。2 CO 3)。DFT过渡态建模支持的机理研究表明,这种化学选择性可以用每个催化体系中一价氢化铜(I)和质子化氢化铜(I)配合物的相对浓度来解释。