An asymmetric hydrogenation of sterically hindered β,β-disubstituted enones has been well-established by using a ruthenium complex composed of an achiral diphosphane and a chiral diamine as catalyst, wherein the carbonyl group was selectively hydrogenated to give a wide range of chiral allylic alcohols with high levels of enantioselectivity and complete chemoselectivity.
A Ruthenium Catalyst with Simple Triphenylphosphane for the Enantioselective Hydrogenation of Aromatic Ketones
作者:Han Zhou、Hanmin Huang
DOI:10.1002/cctc.201300080
日期:2013.8
An efficient Ru catalyst constructed from simple and commercially available triphenylphosphane and enantiopure (1S,1′S)‐1,1′‐biisoindoline (BIDN) was applied to the asymmetric hydrogenation of aromatic ketones. A range of simple aromatic ketones could be hydrogenated with good to excellent enantioselectivities (up to 95 % ee). An appropriate enantioselective transition state was proposed to explain
Non-Heme Iron Catalysts with a Rigid Bis-Isoindoline Backbone and Their Use in Selective Aliphatic C−H Oxidation
作者:Jianming Chen、Martin Lutz、Michela Milan、Miquel Costas、Matthias Otte、Robertus J. M. Klein Gebbink
DOI:10.1002/adsc.201700239
日期:2017.8.7
from a bis‐isoindoline‐bis‐pyridine ligand platform based on the BPBP ligand (BPBP=N,N′‐bis(2‐picolyl)‐2,2′‐bis‐pyrrolidine) have been synthesized and applied in selective aliphatic C−H oxidation with hydrogen peroxide under mild conditions. The introduction of benzene moieties on the bis‐pyrrolidine backbone leads to an increased preference of tertiary over secondary C−H bond oxidation (3°/2° ratio
合成了基于BPBP配体的双异吲哚啉-双吡啶配体平台的铁配合物(BPBP = N, N' -bis(2- picolyl)-2,2' -bis-pyrrolidine)并将其应用于选择性在温和条件下用过氧化氢进行脂肪族CH的氧化。在双吡咯烷主链上引入苯部分会导致叔酸优先于仲CH键氧化(3°/ 2°比,最高33)。另一方面,用大体积的甲硅烷基取代吡啶的间位基团可提高仲CH的氧化选择性,并通常导致更高的产品收率和质量平衡。
An Efficient Synthesis of Chiral Diamines with Rigid Backbones: Application in Enantioselective Michael Addition of Malonates to Nitroalkenes
new and efficient route for synthesis of enantiomerically pure biisoindoline and its isomer based on the diaza-Cope rearrangement reaction with chiral 1,2-bis(2-hydroxylphenyl)-1,2-diaminoethane as starting material has been developed. The newly prepared biisoindoline was employed as a chiralligand in the Ni(II)-catalyzed enantioselectiveMichaeladdition of malonates to conjugated nitroalkenes, and
Enantioselective Epoxidation of Electron-Deficient Alkenes Catalyzed by Manganese Complexes with Chiral N<sub>4</sub>
Ligands Derived from Rigid Chiral Diamines
作者:Xiangning Chen、Bao Gao、Yijin Su、Hanmin Huang
DOI:10.1002/adsc.201700541
日期:2017.8.7
series of tetradentate sp2N/sp3N hybrid chiral N4 ligands derived from rigid chiral diamines were synthesized, which enabled the first manganese-catalyzed enantioselective epoxidation of electron-deficientalkenes with hydrogenperoxide (H2O2) as an oxidant. The reaction furnishes enantiomerically pure epoxy amides, epoxy ketones as well as epoxy esters in good yields and excellent enantioselectivities
合成了一系列衍生自刚性手性二胺的四齿sp 2 N / sp 3 N杂合手性N 4配体,这使锰能够以过氧化氢(H 2 O 2)为氧化剂,首次对缺电子烯烃进行对映选择性环氧化。。该反应以较低的催化剂负载量提供了对映体纯的环氧酰胺,环氧酮以及环氧酯,具有良好的收率和优异的对映选择性(最高99.9%ee)。对结构-活性关系的初步研究表明,保持sp 3的相对较低的供电子能力N和N 2配体的sp 2 N的相对较高的供电子能力有利于获得更高的活性和选择性,从而为我们理解H 2 O 2的环氧化提供了新的视角。