Cascade Reaction by Chemo- and Biocatalytic Approaches to Obtain Chiral Hydroxy Ketones and <i>anti</i>
1,3-Diols
作者:Raffaella Gandolfi、Giorgio Facchetti、Michael S. Christodoulou、Marco Fusè、Fiorella Meneghetti、Isabella Rimoldi
DOI:10.1002/open.201800056
日期:2018.5
biocatalytic cascade approach was applied for the stereoselectivesynthesis of hydroxy ketones and the corresponding 1,3‐diols. A new class of tridentate N,N,O ligands was used with copper(II) complexes for the asymmetric β‐borylation of α,β‐unsaturated compounds. The complex containing ligand L5 emerged as the best performer, and it gave the organoborane derivatives with good ee values. The corresponding keto–alcohol
four-stereogenic centered tetrahydroindolizine intermediates could be efficiently transferred into axially chirality in 3-arylindolizines and vicinal pyridyl and aryl substituted 1,5-diketones. In addition, densely functionalized cyclopropanes and bridgedcyclic compound were also discovered depended on the nature of the pyridinium ylides. Mechanism studies were involved to explain the stereochemistry during the
Reaction condition controlled nickel(<scp>ii</scp>)-catalyzed C–C cross-coupling of alcohols
作者:Meng-Juan Zhang、Hong-Xi Li、David J. Young、Hai-Yan Li、Jian-Ping Lang
DOI:10.1039/c9ob00418a
日期:——
methodology employing a Ni(II) 4,6-dimethylpyrimidine-2-thiolate cluster catalyst under different reaction conditions. This catalyst could tolerate a wide range of substrates and exhibited a high activity for the annulation reaction of secondary alcohols with 2-aminobenzyl alcohols to yield quinolines. This work is an example of precise chemoselectivity control by careful choice of reaction conditions.
The effects of solvent on switchable stereoselectivity: copper-catalyzed asymmetric conjugate additions using D2-symmetric biphenyl phosphoramidite ligands
A highly enantioselective copper-catalyzed conjugateaddition of diethylzinc to acyclic aromatic enones was developed with phosphoramidite ligands bearing a D2-symmetric biphenyl backbone. This type of reaction demonstrated that toluene and THF solvents can completely reverse the absolute configuration of the products, thus simplifying the process of accessing either enantiomer (S: 92% ee, 94% yield;
In this study, the authors have designed and synthesized a novelseries of 3-acyl-4-aryl-4,5-dihydropyrazoles, with the aim to obtain new potential scaffolds for the inhibition of both isoforms of monoamine oxidase (MAO) enzyme. The synthetic pathway to these compounds includes as a key step the 1,3-dipolar cycloaddition reaction of diazomethane with a chalcone. All the compounds were fully characterized