Search results for "405"

Palladium-catalysed direct cross-coupling of secondary alkyllithium reagents

2014

Palladium-catalysed cross-coupling of secondary C(sp(3)) organometallic reagents has been a long-standing challenge in organic synthesis, due to the problems associated with undesired isomerisation or the formation of reduction products. Based on our recently developed catalytic C-C bond formation with organolithium reagents, herein we present a Pd-catalysed cross-coupling of secondary alkyllithium reagents with aryl and alkenyl bromides. The reaction proceeds at room temperature and on short timescales with high selectivity and yields. This methodology is also applicable to hindered aryl bromides, which are a major challenge in the field of metal catalysed cross-coupling reactions.

Unprecedented reactivity of a Schiff base ligand in the co-ordination sphere of copper(I) complex towards β-diketones. Synthesis and X-ray characteri…

2002

International audience; The reactions of the copper(I) derivative [CuL(THF)(CH3CN)]PF6 (1), in which L is the di-imine/pyridine ligand 2,6-bis[1-(2,6-diisopropylphenylimino)ethyl]pyridine, with different β-diketones (2,4-pentanedione (acacH), 1,3-diphenyl-1,3-propanedione (dbm)) yielded the new Cu(I) salt [CuL′2]PF6 (2) (L′: 2-[acetyl]-6-[1-(2,6-diisopropylphenylimino)ethyl]pyridine). These reactions of β-diketones with a di-imine/pyridine ligand co-ordinated to a Cu(I) centre constitute the first example of a partial hydrolysis of such a Schiff base within the inner sphere of a Cu centre. Compound 2·acaH has been characterised by X-ray crystallography. © 2002 Elsevier Science B.V. All righ…

DFT and experimental studies on structure and spectroscopic parameters of 3,6-diiodo-9-ethyl-9H-carbazole

2015

The first report on crystal and molecular structure of 3,6-diiodo-9-ethyl-9H-carbazole is presented. Experimental room-temperature X-ray and 13C chemical shift studies were supported by advanced theoretical calculations using density functional theory (DFT). The 13C nuclear magnetic shieldings were predicted at the non-relativistic and relativistic level of theory using the zeroth-order regular approximation (ZORA). Theoretical relativistic calculations of chemical shifts of carbons C3 and C6, directly bonded to iodine atoms, produced a reasonable agreement with experiment (initial deviation from experiment of 44.3 dropped to 4.25 ppm). The changes in ring aromatic character via simple harm…

An overview on chemical structures as ΔF508-CFTR correctors

2019

Deletion of phenylalanine at position 508 (F508del) in the CFTR protein, is the most common mutation causing cystic fibrosis (CF). F508del causes misfolding and rapid degradation of CFTR protein a defect that can be targeted with pharmacological agents termed “correctors”. Correctors belong to various chemical classes but are generally small molecules based on nitrogen sulfur or oxygen heterocycles. The mechanism of action of correctors is generally unknown but there is experimental evidence that some of them can directly act on mutant CFTR improving folding and stability. Here we overview the characteristics of the various F508del correctors described so far to obtain indications on key ch…

Influència dels estereotips de gènere en les adolescents i els adolescents de La Safor, València: una aproximació a l'autopercepció i la construcció …

2018

Structure and Electronic Properties of an Expanded Terpyridine Complex of Nickel(II) [Ni(ddpd)2](BF4)2

2018

Synthesis of β-P,N Aminophosphines and Coordination Chemistry to PdII. X-ray Structures of [PdCl2(Ph2PCH2CH(Ph)NHPh-κP,κN)] and [PdCl(η3-C3H5)(Ph2PCH…

2001

The reaction of the CN bond in PhCHNPh with the carbanionic species Ph2PCH2-, leading to the N-phenyl β-aminophosphine Ph2PCH2CH(Ph)NHPh, L1, is described. This molecule reacts with different organ...

β-Amino alcohols from anilines and ethylene glycol through heterogeneous Borrowing Hydrogen reaction

2017

Abstract Borrowing Hydrogen (BH), also called Hydrogen Autotransfer (HA), reaction with neat ethylene glycol represents a key step in the preparation of β-amino alcohols. However, due to the stability of ethylene glycol, mono-activation has rarely been achieved. Herein, a combination of Pd/C and ZnO is reported as heterogeneous catalyst for this BH/HA reaction. This system results in an extremely air and moisture stable, and economic catalyst able to mono-functionalize ethylene glycol in water, without further activation of the diol. In this work, different diols and aromatic amines have been explored affording a new approach towards amino alcohols. This study reveals how the combination of…

The wet synthesis and quantification of ligand-free sub-nanometric Au clusters in solid matrices.

2017

© The Royal Society of Chemistry. The synthesis of ligand-free sub-nanometric metal clusters on a large scale suffers typically from very low yields (15% yields, as unambiguously determined using a very simple and extremely sensitive analytical reaction test.

Polymorphism in a π stacked Blatter radical: structures and magnetic properties of 3-(phenyl)-1-(pyrid-2-yl)-1,4-dihydrobenzo[ e ][1,2,4]triazin-4-yl

2020

International audience; 3-(Phenyl)-1-(pyrid-2-yl)-1,4-dihydrobenzo[e][1,2,4]triazin-4-yl (2) demonstrates the first example of polymorphism in the family of Blatter radicals. Two polymorphs, 2α and 2β, have been identified and characterized by single crystal X-ray diffractometry and magnetic susceptibility measurements to investigate their magnetism–structure correlations. Both polymorphs form one-dimensional (1D) π stacks of evenly spaced radicals with distinctly different π–π overlap modes. Within the 1D π stacks, radicals are located at evenly interplanar distances, 3.461 Å for 2α and 3.430 Å for 2β. Magnetic susceptibility studies indicate that both polymorphs exhibit antiferromagnetic …