By Hélène Pellissier

The objective of this ebook is to teach the excessive strength of chiral sulfur-containing ligands to advertise various uneven catalytic variations. the real variety of reviews seemed within the literature during the last 35 years usually highlighted fantastic ends up in phrases of potency and enantioselectivity, permitting entry to many biologically vital molecules, which essentially demonstrates that those ligands can now be acknowledged as genuine opponents to the extra ordinary phosphorus- or nitrogen-containing ligands. A key aspect of reference for post-graduate scholars, researchers and lecturers.

Show description

Read Online or Download Chiral Sulfur Ligands: Asymmetric Catalysis (RSC Catalysis Series) PDF

Similar chemistry books

Water Scarcity in the Mediterranean: Perspectives Under Global Change

Water shortage impacts hydrologic assets, platforms connectivity, biodiversity, water caliber, and river surroundings functioning. It has direct affects on fiscal sectors that use and depend upon water, equivalent to agriculture, tourism, undefined, power and shipping. The Mediterranean Basin is without doubt one of the areas on the earth so much at risk of weather adjustments, in addition to probably the most impacted by way of human water call for.

Extra info for Chiral Sulfur Ligands: Asymmetric Catalysis (RSC Catalysis Series)

Example text

On the other hand, a novel chiral xylofuranose-based phosphinooxathiane ligand was found by Nakano et al. 50 This ligand was easily prepared from commercially available 1,2-O-isopropylidene-D-xylofuranose in five steps. In order to explain the absolute configuration of the product, these authors have proposed a nucleophilic attack occurring at the allyl terminus trans to the phosphorus atom, which was the better p-acceptor. 17 Furanoside thioether-phosphinite ligand for Pd-catalysed allylic substitutions of acyclic and cyclic allylic substrates.

They proposed a possible mechanism for the chirality transfer, controlled by the steric environment of the chiral imine-sulfur chelate ligand with the reaction occurring trans to the imine donor. 74 In 2005, Kunieda et al. 75 The first successful use of simple 1,2-aminothioethers as hybrid ligands in the test reaction was reported by Bulman Page et al. 39), whereas poor enantioselectivities were obtained when the sulfur atom was substituted with an aromatic group. These authors explained these results by steric and not electronic considerations.

Due to the fact that the steric effect near the sulfur atom was less important than near the nitrogen atom, the enantioselection was much weaker. In 2001, a new chiral bis(benzothiazines) ligand was reported by Harmata et al. 101 The authors studied, in particular, different reaction conditions to perform this reaction and proved that good yields and enantioselectivities were obtained in relatively nonpolar solvents, whereas the reaction remained racemic in dichloromethane S O R R = CH2i-Pr: 87% ee = 16% (S) R = i-Pr: 89% ee = 56% (S) R = Bn: 84% ee = 14% (R) R = Ph: 86% ee = 19% (S) O R R = CH2i-Pr: 88% ee = 74% (R) R = i-Pr: 86% ee = 75% (R) R = Bn: 83% ee = 73% (R) R = Ph: 90% ee = 86% (R) Test reaction with bis(thiazolines) ligands bridged by a dibenzo[a,c]cycloheptadiene backbone.

Download PDF sample

Download Chiral Sulfur Ligands: Asymmetric Catalysis (RSC Catalysis by Hélène Pellissier PDF
Rated 4.54 of 5 – based on 50 votes