Stereocontrolled Fluorobenzylation of Vinyl Sulfones and α,β-Unsaturated Esters Mediated by a Remote Sulfinyl Group. Synthesis of Functionalized Enantiomerically Pure Benzylic Fluorides
摘要:
A sulfinyl group in an ortho position confers enough chemical and configurational stability to monofluorobenzylcarbanions to evolve in a completely stereoselective way in their reactions with beta-substituted vinyl sulfones and alpha,beta-unsaturated esters. Reactions afford easily separable mixtures of two epimers differing in the configuration of the center derived from the Michael acceptor (up to 98% de). They can be easily converted into enantiomerically pure gamma-fluorinated gamma-phenylsulfones and gamma-phenylesters bearing two chiral centers.
Methionine-functionalized chitosan-Pd(0) complex: A novel magnetically separable catalyst for Heck reaction of aryl iodides and aryl bromides at room temperature in water as only solvent
作者:Abdol R. Hajipour、Zeinab Tavangar-Rizi
DOI:10.1002/aoc.3638
日期:2017.7
We report a novel catalyst system with an immobilized palladium metal‐containing magnetic nanoparticle core (ImmPd(0)‐MNPs) for the Heckreaction. ImmPd(0)‐MNPs was found to be an exceptionally mild and versatile catalyst for the Heckreaction of aryl iodides and bromides at room temperature. The catalyst was simply recovered using an external magnet from the reaction mixture and recycled six times
A novel bisoxazoline/Pd composite microsphere: a highly active catalyst for Heck reactions
作者:Junke Wang、Yingxiao Zong、Guoren Yue、Yulai Hu、Xicun Wang
DOI:10.1039/c5ra16510e
日期:——
A novel bisoxazoline/Pd microsphere catalyst was successfully prepared. The structure of the solid catalyst was characterized by SEM, TGA and FT-IR. The catalyst exhibits excellent activity for the Heckreaction. Moreover, the catalyst shows outstanding stability and reusability, can be recovered simply and effectively and reused six times without any activity decrease.
emission spectroscopy (ICP-AES) and thermo gravimetric analysis (TGA). The catalyst has been successfully employed in Suzuki-Miyaura as well as Mizoroki–Heckcross-couplingreactions. The reactions proceed smoothly resulting in the high yields of cross-coupling products (81 to 95%) within short reaction times. The catalyst can be efficiently recovered by simple filtration and reused for multiple cycles
在本工作中,一种新型,高效,可回收的有机-无机杂化多相催化剂(Pd(II)-AMP-Cell @ Al 2 O 3通过将2-氨基吡啶共价接枝在氯丙基改性的纤维素-氧化铝复合材料上,然后与乙酸钯络合来制备)。通过扫描电子显微镜(SEM),透射电子显微镜(TEM),能量色散X射线光谱(EDX),X射线衍射(XRD),电感耦合等离子体原子发射光谱(ICP- AES)和热重分析(TGA)。该催化剂已成功用于Suzuki-Miyaura以及Mizoroki-Heck交叉偶联反应。反应平稳进行,从而在较短的反应时间内获得了高产率的交叉偶联产物(81%至95%)。可以通过简单的过滤有效地回收催化剂,并将其重复使用多次,而不会显着降低催化活性。
Pd and Ni complexes of a novel vinylidene β-diketimine ligand: Their application as catalysts in Heck coupling and alkyne trimerization
作者:Raghavendra Beesam、Dastagiri Reddy Nareddula
DOI:10.1002/aoc.3696
日期:2017.9
A β‐diketimine ligand with vinylidene substitution at γ‐carbon, CH2C(CH3CNAr)2 (Ar = 2,6‐diisopropylphenyl) (L2), was synthesized by treating β‐diketimine H2C(CH3CNAr)2 with n‐BuLi followed by paraformaldehyde. L2 formed the homobimetallic ether‐bridged β‐diketiminatecomplex [O(CH2‐β‐diketiminate)Pd(OAc)}2] (1) with (PdOAc)2. It also gave complexes [L2PdCl2] (2) and [L2NiBr2] (3) when treated with