The B(C<sub>6</sub>F<sub>5</sub>)<sub>3</sub>-Catalyzed Tandem Meinwald Rearrangement–Reductive Amination
作者:Martine R. Tiddens、Robertus J. M. Klein Gebbink、Matthias Otte
DOI:10.1021/acs.orglett.6b01744
日期:2016.8.5
A system of three coupledcatalytic cycles enabling the one-pot transformation of epoxides to amines via Meinwald rearrangement, imine condensation, and iminereduction is described. This assisted tandem catalysis is catalyzed by B(C6F5)3 resulting in the first tandem Meinwald rearrangement–reductive amination protocol. The reaction proceeds in nondried solvents and yields β-functionalized amines.
描述了三个耦合的催化循环的系统,该系统能够通过Meinwald重排,亚胺缩合和亚胺还原将环氧化物一锅转化为胺。这种辅助的串联催化由B(C 6 F 5)3催化,从而产生了第一个串联的Meinwald重排-还原胺化方案。该反应在未干燥的溶剂中进行,并产生β-官能化的胺。特别地,以高收率获得β-二芳基胺。
Development and Application of a Poly(ethylene glycol)-Supported Triarylphosphine Reagent: Expanding the Sphere of Liquid-Phase Organic Synthesis
作者:Frank Sieber、Paul Wentworth、Jonathan D. Toker、Anita D. Wentworth、William A. Metz、Neal N. Reed、Kim D. Janda
DOI:10.1021/jo9903712
日期:1999.7.1
into the utility of poly(ethyleneglycol) (PEG)-supportedtriarylphosphines as functional polymer reagents in liquid-phaseorganic synthesis (LPOS) are being pursued. This report describes the synthesis and NMR characterization of an aryl-alkyl ether-linked PEG-triarylphosphine derivative (2) and its subsequent application in LPOS. The utility of 2 as a mild stoichiometric reagent for ozonide reduction
examined. With a straightforward catalyst system composed of diironnonacarbonyl and tributyl phosphane, excellent yields and chemoselectivities (>99 %) were obtained for the formation of the corresponding alkenes. After studying the reaction conditions, and the scope and limitations of the reaction, several attempts were undertaken to shed light on the reaction mechanism.
Stereoselective iron-catalyzed alkyne hydrogenation in ionic liquids
作者:Tim N. Gieshoff、Alice Welther、Michael T. Kessler、Martin H. G. Prechtl、Axel Jacobi von Wangelin
DOI:10.1039/c3cc49679a
日期:——
Iron(0) nanoparticles in ionic liquids (ILs) have been shown to catalyse the semi-hydrogenation of alkynes. In the presence of a nitrile-functionalised IL or acetonitrile, stereoselective formation of (Z)-alkenes was observed. The biphasic solvent system allowed facile separation and re-use of the catalyst.
Ligand-free (<i>Z</i>)-selective transfer semihydrogenation of alkynes catalyzed by <i>in situ</i> generated oxidizable copper nanoparticles
作者:Rafał Kusy、Karol Grela
DOI:10.1039/d1gc01206a
日期:——
of a semihydrogenation reaction results in the formation of a water-soluble ammonia complex, so that the catalyst may be reused several times by simple phase-separation with no need for any special regeneration processes. Formed NH4B(OR)4 can be easily transformed back into ammonia-borane or into boric acid. In addition, a one-pot tandem sequence involving a Suzuki reaction followed by semihydrogenation
在此,我们提出了在氢供体(如氨硼烷和绿色质子溶剂)存在下,基于原位生成的 CuNPs的炔烃的( Z ) 选择性转移半氢化。这种环保方法的特点是操作简单,同时具有高立体选择性和化学选择性以及官能团兼容性。CuNPs在半氢化反应完成后自动氧化形成水溶性氨络合物,因此催化剂可以通过简单的相分离多次重复使用,无需任何特殊的再生过程。形成NH 4 B(OR) 4可以很容易地转化回氨硼烷或硼酸。此外,还提出了涉及 Suzuki 反应和半氢化的一锅串联序列,这可以最大限度地减少化学废物的产生。