114937-27-8Relevant articles and documents
Easily accessible TADDOL-derived bisphosphonite ligands: Synthesis and application in the asymmetric hydroformylation of vinylarenes
Allmendinger, Simon,Kinuta, Hirotaka,Breit, Bernhard
supporting information, p. 41 - 45 (2015/03/03)
The synthesis of chiral bidentate bisphosphonite ligands based on the TADDOL motif from readily available starting materials has been developed. Taking advantage of the modular nature of the building blocks, a diverse ligand library has been prepared. Their catalytic potential has been evaluated in the asymmetric hydroformylation of styrene and derivatives. These catalysts showed high activity and provided the aldehydes in high enantiomeric purity.
Synthesis and application of modular phosphine-phosphoramidite ligands in asymmetric hydroformylation: Structure-selectivity relationship
Zhang, Xiaowei,Cao, Bonan,Yan, Yongjun,Yu, Shichao,Ji, Baoming,Zhang, Xumu
experimental part, p. 871 - 877 (2010/06/20)
A series of hybrid phos- phine-phosphoramidite ligands has been designed and synthesized in moderate yields from chiral BINOL (1, 1′- bi-2-naphthol) or NOBIN (2-amino-2′- hydroxy-1, 1′-binaphthyl). They have achieved highly regio- and enantiose- lectivities in Rh-catalyzed asymmetric hydroformylations of styrene derivatives (branched/linear ratio up to 56.6, ee up to 99%), vinyl acetate derivatives (up to 98% ee), and allyl cyanide (up to 96 % ee). Systematic variation of ligand structure showed that the steric factor on the phsophoramidite moiety determined the performance of the ligand. With the increased hindrance, the branched/linear ratio rose, while the ee value dropped in the hydrofor- mylation of styrene. However, the N- substituents did not influence the selec- tivities much.
Tunable phosphinite, phosphite and phosphoramidite ligands for the asymmetric hydrovinylation reactions
Park, Haengsoon,Kumareswaran, Ramaiah,RajanBabu
, p. 6352 - 6367 (2007/10/03)
Only a limited number of ligands have been successfully employed for the Ni-catalyzed asymmetric hydrovinylation reaction. Diarylphosphinites, carrying β-acylamino groups prepared from readily available carbohydrates, in conjunction with highly dissociated counteranions {[(3,5-(CF3) 2C6H3]4B- or SbF 6-}, effect the hydrovinylation of vinylarenes under ambient pressure of ethylene with high enantioselectivity. Nitrogen substituents such as -COCF3 and COPh groups lead to isomerization of the primary products (3-arylbutenes) to Z- and E-2-aryl-2-butenes. In a prototypical synthesis of a 2-arylproionic acid, (S)-3-(4-bromophenyl)-1-butene (89% ee) has be transformed into (R)-ibuprofen by Ni-catalyzed cross-coupling with i-BuMgBr, followed by oxidation of the double bond with NaIO4 and KMnO 4. Asymmetric codimerization of norbonene and ethylene using binaphthol-derived phosphoramidites as ligands gives 1:1, 2:1 or polymeric adducts depending on the relative configurations and nature of the BINAP and amine moieties. With one of the phosphoramidite-Ni complexes, counteranions BAr4- [Ar=3,5-(CF3)2C 6H3] and SbF6-, which had been used interchangeably in other reactions, give either a 1:1 adduct or a 2:1 adduct, respectively.
