Polymer-Stabilized Palladium Nanoparticles for the Chemoselective Transfer Hydrogenation of α,β-Unsaturated Carbonyls: Single-Step Bottom-Up Approach
作者:Sanjit K. Mahato、Rafique Ul Islam、Chiranjit Acharya、Michael J. Witcomb、Kaushik Mallick
DOI:10.1002/cctc.201300985
日期:2014.3.19
Polypyrrole stabilised palladium nanoparticles show good catalytic efficiency for the chemoselective transfer hydrogenation of α,β‐unsaturated carbonyl compounds. The catalyst is very specific and selectively hydrogenates the olefins or acetylenes only, without affecting the carbonyl moiety, with an excellent yield of products for a wide range of substrates.
Reduction of Activated Alkenes by P
<sup>III</sup>
/P
<sup>V</sup>
Redox Cycling Catalysis
作者:Lars Longwitz、Thomas Werner
DOI:10.1002/anie.201912991
日期:2020.2.10
using a phosphetane oxide catalyst in the presence of a simple organosilane as the terminal reductant and water as the hydrogen source. Quantitative hydrogenation was observed when 1.0 mol % of a methyl‐substituted phosphetane oxide was employed as the catalyst. The procedure is highly selective towards activated double bonds, tolerating a variety of functional groups that are usually prone to reduction
Direct Photoredox‐Catalyzed Reductive Difluoromethylation of Electron‐Deficient Alkenes
作者:Xiao‐Jun Tang、Zuxiao Zhang、William R. Dolbier
DOI:10.1002/chem.201504363
日期:2015.12.21
Photoredox‐catalyzed reductivedifluoromethylation of electron‐deficient alkenes was achieved in one step under tin‐free, mild and neutral conditions. This protocol affords a facile method to introduce RCF2 (R=H, Ph, Me, and CH2N3) groups at sites β to electron‐withdrawing groups. It was found that TTMS (tris(trimethylsilyl)silane) served nicely as both the H‐atom donor and the electron donor in the
在缺锡,温和和中性的条件下,一步一步就可以完成缺氧烯烃的光氧化还原催化的还原性二氟甲基化反应。该方案提供了一种简便的方法,可将β位的RCF 2(R = H,Ph,Me和CH 2 N 3)基团引入吸电子基团。发现TTMS(三(三甲基甲硅烷基)硅烷)在催化循环中既可以作为氢原子供体,也可以作为电子供体。实验和DFT计算结果提供了RCF 2(R = H,Ph,Me)自由基本质上亲核的证据。
Facile synthesis of libraries of functionalized cyclopropanes and oxiranes using ionic liquids – A new approach to the classical Corey-Chaykovsky reaction
作者:Shruti S. Malunavar、Suraj M. Sutar、Pavankumar Prabhala、Hemantkumar M. Savanur、Rajesh G. Kalkhambkar、Gopalakrishnan Aridoss、Kenneth K. Laali
DOI:10.1016/j.tetlet.2021.153339
日期:2021.9
[PAIM][NTf]/BMIM-ILs as a base/solvent in the Corey-Chaykovsky reaction is demonstrated by the facile synthesis of libraries of functionalized cyclopropanes from enones and oxiranes from aldehydes and ketones, at room temperature in respectable isolated yields. To demonstrate their application, the synthesized epoxides were employed as substrates for the synthesis of a library of 2,3-disubstituted quinolines, using
Application of E1cB Elimination in Asymmetric Organocatalytic Cascade Reactions To Construct Polyheterocyclic Compounds
作者:Zhi-Hao You、Ying-Han Chen、Yu Tang、Yan-Kai Liu
DOI:10.1021/acs.orglett.9b03138
日期:2019.10.18
By introducing a carbon functionality at 2-position of chromane, the formal asymmetric functionalization of the 3-position of 2-substituted chromane has been realized via a highly chemo-, regio-, and stereoselective organocatalyticcascadereaction in a sequential one-pot manner involving an E1cB mechanism governed ring-opening process. Critical to our success was the design of a chiral dipeptide-based