Organic synthesis via magnetic attraction: benign and sustainable protocols using magnetic nanoferrites
作者:R. B. Nasir Baig、Rajender S. Varma
DOI:10.1039/c2gc36455g
日期:——
Magnetic nano-catalysts have been prepared using simple modification of iron ferrites. The nm size range of these particles facilitates the catalysis process, as an increased surface area is available for the reaction; the easy separation of the catalysts by an external magnet and their recovery and reuse are additional beneficial attributes. Glutathione bearing nano-ferrites have been used as organocatalysts for the Paal–Knorr reaction and homocoupling of boronic acids. Nanoferrites, post-synthetically modified by ligands, were used to immobilize nanometals (Cu, Pd, Ru, etc.) which enabled the development of efficient, sustainable and green procedures for azide–alkynes-cycloaddition (AAC) reactions, C–S coupling, O-allylation of phenol, Heck-type reactions and hydration of nitriles.
A Chiral Sulfoxide-Ligated Ruthenium Complex for Asymmetric Catalysis: Enantio- and Regioselective Allylic Substitution
作者:Barry M. Trost、Meera Rao、André P. Dieskau
DOI:10.1021/ja411310w
日期:2013.12.11
and synthesis of a novel chiral sulfoxide-ligated cyclopentadienyl ruthenium complex is described. Its utility as an asymmetric variant of [CpRu(MeCN)3]PF6 is demonstrated through its ability to function in the branched-selective asymmetric allylic alkylation of phenols and carboxylic acids. Water has also been shown to act as a competent nucleophile in this reaction to generate branched allyl alcohols
Imidazolium‐Oxazoline Salts in Ruthenium‐Catalyzed Allylic Substitution and Cross Metathesis of Formed Branched Isomers
作者:Hamed Ben Ammar、Bechir Ben Hassine、Cédric Fischmeister、Pierre H. Dixneuf、Christian Bruneau
DOI:10.1002/ejic.201000718
日期:2010.10
Imidazolium-oxazoline chlorides have been prepared from chloroacetonitrile and used to generate bidentate mixed NHC-oxazoline ligands for ruthenium-catalyzed substitution of cinnamylchloride by phenols. These ligands associated to [RuCp*(MeCN)3][PF6] promote allylic substitution reactions at room temperature with high regioselectivity in favour of the branched isomers giving terminal alkenes. These allylic ethers
Pd-Catalyzed Substitution of the OH Group of Nonderivatized Allylic Alcohols by Phenols
作者:Thanya Rukkijakan、Sunisa Akkarasamiyo、Supaporn Sawadjoon、Joseph S. M. Samec
DOI:10.1021/acs.joc.7b03274
日期:2018.4.6
Nonactivated phenols have been employed as nucleophiles in the allylation of nonderivatized allylic alcohols to generate allylated phenolic ethers with water as the only byproduct. A Pd[BiPhePhos] catalyst was found to be reactive to give the O-allylated phenols in good to excellent yields in the presence of molecular sieves. The reactions are chemoselective in which the kinetically favored O-allylated
Facilepreparations of chiral [Ru(Cp*)]- and [Ru(Cp′)]-based allyl complexes featuring N,O chelate derived from (+)-nopinone are described. Single crystal X-ray structural analysis of one complex revealed the preferential configuration of the ruthenium centre and the orientation of the unsymmetrical allylic substituent. Applications of these complexes in catalysis for nucleophilicallylic substitution