Synthesis and structural characterisation of zinc complexes bearing furanylmethyl and thiophenylmethyl derivatives of (R,R)-1,2-diaminocyclohexanes for stereoselective polymerisation of poly(rac-lactide)
摘要:
Novel dichloro zinc complexes based on enantiopure N,N-diamine ligands bearing furanylmethyl and thiophenylmethyl pendent groups were synthesised, and their crystal structures were determined using X-ray crystallography. The isopropoxide derivatives (generated in situ) of these well-characterised complexes efficiently catalysed the ring-opening polymerisation (ROP) of rac-lactide (rac-LA) at two different temperatures under controlled conditions. Highly heterotactic polylactide (PIA) was obtained with P-r = 0.80 at -25 degrees C in THF. Crown Copyright (C) 2014 Published by Elsevier Ltd. All rights reserved.
Novel Chiral Diamino-Oligothiophenes as Valuable Ligands in Pd-Catalyzed Allylic Alkylations. On the “Primary” Role of “Secondary” Interactions in Asymmetric Catalysis
A new class of chiral C2-symmetrical diamino-oligothiophenes is described to be effective in catalyzing Pd-mediated asymmetricallylicalkylations in a highly enantioselective manner. The combination of experimental as well as crystallographic evidence revealed the key role played by sulfur-based heteroaromatic rings in the stereodiscriminating step of the procedure. In particular, unprecedented non-covalent
[EN] POLYDENTATE LIGANDS AND THEIR COMPLEXES FOR MOLECULAR CATALYSIS<br/>[FR] LIGANDS POLYDENTATES ET LEURS COMPLEXES POUR LA CATALYSE MOLÉCULAIRE
申请人:LOS ALAMOS NAT SECURITY LLC
公开号:WO2015191505A1
公开(公告)日:2015-12-17
The present invention relates generally to novel achiral and chiral sulfur-, nitrogen- and phosphorus-containing ligands, designated as NNS-type, P(0)NS-type, PNS-type, SNNS-type, SNNP(0)-type, or SNNP-type polydentate ligands and transition metal complexes of these ligands. The catalysts derived from these ligands and transition metal complexes may be used in a wide range of catalytic reactions, including hydrogenation and transfer hydrogenation of unsaturated organic compounds, dehydrogenation of alcohols and boranes, various dehydrogenative couplings, and other catalytic transformations.
When is an imine not an imine? Unusual reactivity of a series of Cu(ii) imine-pyridine complexes and their exploitation for the Henry reaction
作者:Christine J. Cooper、Matthew D. Jones、Simon K. Brayshaw、Benjamin Sonnex、Mark L. Russell、Mary F. Mahon、David R. Allan
DOI:10.1039/c0dt01740j
日期:——
In this paper we report the synthesis and solid-state structures for a series of pyridine based Cu(II) complexes and preliminary data for the asymmetric Henry reaction. Interestingly, the solid-state structures indicate the incorporation of an alcohol into one of the imine groups of the ligand, forming a rare α-amino ether group. The complexes have been studied viasingle crystal X-ray diffraction,
Nitroalkenes in the Ni(II) Catalyzed Asymmetric<i>Michael</i>Addition. Convenient Route to the Key Intermediate of Brivaracetam
作者:Alexander N. Reznikov、Leonid E. Kapranov、Valentina V. Ivankina、Anastasiya E. Sibiryakova、Victor B. Rybakov、Yuri N. Klimochkin
DOI:10.1002/hlca.201800170
日期:2018.12
A series of Ni(II) complexes with novel chiral ligands derived from (1R,2R)‐1,2‐diphenylethane‐1,2‐diamine was synthesized. The catalytic activity of these complexes in the asymmetricMichael reaction is demonstrated. Asymmetricaddition of diethyl malonate to ω‐nitrostyrene and 1‐nitropent‐1‐ene in the presence of these complexes leads to the enantiomerically enriched diethyl (S)‐2‐(2‐nitro‐1‐phenylethyl)malonate
A new class of chiraloligothiophenes is described. Mono-, bi-, ter-, and quarterthiophenes have been linked to enantiopure trans-1,2-cyclohexanediamine (DACH) via diamino or diimino moieties. The stereochemistry of DACH, the type of linker, and oligothiophene size determine the conformational flexibility of these molecules and consequently their molecular and supramolecular helicity in solution and