479586-33-9Relevant academic research and scientific papers
Cellulose-supported chiral rhodium nanoparticles as sustainable heterogeneous catalysts for asymmetric carbon-carbon bond-forming reactions
Yasukawa, Tomohiro,Miyamura, Hiroyuki,Kobayashi, Shu
, p. 6224 - 6229 (2015)
Cellulose-supported chiral Rh nanoparticle (NP) catalysts have been developed. The Rh NPs, which were well dispersed on cellulose, catalyzed the asymmetric 1,4-addition of arylboronic acids to enones and enoates, one of the representative asymmetric carbon-carbon bond-forming reactions, in the presence of chiral diene ligands, providing the corresponding adducts in high yields with outstanding enantioselectivities without metal leaching. The solid-state NMR analysis of the chiral NP system directly suggested interactions between the Rh NPs and the chiral ligand on cellulose. This is the first example of using polysaccharide-supported chiral metal nanoparticles for asymmetric carbon-carbon bond-forming reactions.
Asymmetric construction of a ferrocenyl phosphapalladacycle from achiral enones and a demonstration of its catalytic potential
Gan, Kennard,Sadeer, Abdul,Xu, Chang,Li, Yongxin,Pullarkat, Sumod A.
, p. 5074 - 5076 (2014)
A new approach toward ferrocenyl phosphapalladacycle construction from achiral enones via asymmetric hydrophosphination and subsequent diastereoselective C-H activation is described. Its catalytic efficacy toward C-C bond formation is subsequently illustr
Fine-Tuning the Bicyclo[3.3.1]nona-2,6-diene Ligands: Second Generation 4,8-Substituted Dienes for Rh-Catalyzed Asymmetric 1,4-Addition Reactions
Bieliūnas, Vidmantas,Ston?ius, Sigitas
, p. 3815 - 3823 (2021/07/28)
Design and synthesis of the second generation C2-symmetric 4,8-endo,endo-bis(alkoxy) bicyclo[3.3.1]nona-2,6-diene ligands possessing additional 4,8-exo,exo substituents is reported. The 4,8-exo,exo groups provide a further element for fine-tuning of the ligand structure by enforcing conformational rigidity of the 4,8-endo,endo side chains. Such tetrasubstituted bicyclo[3.3.1]nona-2,6-dienes were employed as steering ligands in the rhodium-catalyzed arylation of cyclic enones with arylboronic acids, providing the corresponding 1,4-addition products in good to excellent yields (69–99 %) and enantioselectivities up to 99 % ee.
Enantioselective Hydrogenation of Endocyclic Enones: the Solution to a Historical Problem?
Lang, Qiwei,Yang, Huaxin,Gu, Guoxian,Feng, Qiang,Wen, Jialin,Zhang, Xumu
supporting information, p. 933 - 936 (2021/03/03)
The enantioselective hydrogenation of endocyclic enones has been a historical problem for homogeneous catalysis. We herein report an efficient method to reduce endocyclic enones with molecular hydrogen. Catalyzed by a rhodium/Zhaophos complex, a variety of enones with five-, six- or seven-member ring were hydrogenated with high enantioselectivity (92%—99% ee). Excellent chemo- and enantioselectivity demonstrated this method was successfully applied in the enantioselective hydrogenation of citral to produce enantio-enriched citronellal.
Enantioselective Conjugate Addition of Stabilized Arylzinc Iodide to Enones: an Improved Protocol of the Hayashi Reaction
Casotti, Gianluca,Rositano, Vincenzo,Iuliano, Anna
, p. 1126 - 1131 (2020/12/17)
Stabilised arylzinc iodide, prepared by direct insertion of zinc into aryl iodides, were used as nucleophiles in the Hayashi Rh-catalysed enantioselective conjugate addition to enones. The reaction conditions were optimized in the addition of phenylzinc i
Chiral N-aryl tert-butanesulfinamide-olefin ligands for rhodium-catalyzed asymmetric 1,4-addition of aryl boronic acids to cyclic enones
Yuan, Shuai,Zeng, Qingle,Wang, Jiajun,Zhou, Lihong
supporting information, p. 32 - 42 (2021/02/09)
Chiral N-aryl sulfinamide-olefins which are readily synthesized via C-N coupling and nucleophilic substitution have been used as chiral ligands, which demonstrate moderate to excellent asymmetric catalytic performance in the rhodium-catalyzed asymmetric 1
Organic Solvent-free Asymmetric 1,4-Addition in Liquid- or Solid-State using Conventional Stirring Catalyzed by a Chiral Rhodium Complex Developed as a Homogeneous Catalyst
Korenaga, Toshinobu,Kori, Hiroto,Asai, Shota,Kowata, Ryo,Shirai, Masayuki
, p. 6059 - 6066 (2020/10/28)
Organic solvent-free asymmetric 1,4-addition of arylboronic acids to enone substrates was performed by using a chiral rhodium complex catalyst developed as a homogeneous catalyst. Reactions catalyzed by [RhOH(cod)]2 with chiral diphosphine ligands in liquid- or solid-state proceeded to give chiral 1,4-adducts in high yield with enantioselectivities up to ca. 100 % ee by conventional stirring without mechanochemistry such as ball milling. The solid-state reactions under a static condition also proceeded, but with a slight decrease in enantioselectivity of the 1,4-adduct. SEM observations of the solid-state reactions indicated that no nanoparticles catalyst was generated. The organic solvent-free reaction could be applied to gram-scale synthesis by performing a greener purification using a minimum necessary organic solvent.
Heterogeneous Rh and Rh/Ag bimetallic nanoparticle catalysts immobilized on chiral polymers
Min, Hyemin,Miyamura, Hiroyuki,Yasukawa, Tomohiro,Kobayashi, Shu
, p. 7619 - 7626 (2019/08/20)
The development of heterogeneous chiral catalysts has lagged far behind that of homogeneous chiral catalysts in spite of their advantages, such as environmental friendliness for a sustainable society. We describe herein novel heterogeneous chiral Rh and Rh/Ag bimetallic nanoparticle catalysts consisting of polystyrene-based polymers with chiral diene moieties. The catalysts enable high-to-excellent yields and enantioselectivities to be obtained in asymmetric 1,4-addition reactions of arylboronic acids with α,β-unsaturated carbonyl compounds such as ketones, esters, and amides, and in other asymmetric reactions. The catalysts could be readily recovered by simple filtration and reused; they could also be applied to continuous-flow synthesis. We also discuss the nature of possible reaction species based on XPS analysis.
Heterogeneous Chiral Diene-Rh Complexes for Asymmetric Arylation of α,β-Unsaturated Carbonyl Compounds, Nitroalkenes, and Imines
Kuremoto, Tatsuya,Yasukawa, Tomohiro,Kobayashi, Shū
supporting information, p. 3698 - 3703 (2019/07/12)
A chiral diene ligand with tertiary alkyl amine-derived secondary amide moiety was immobilized on cross-linked polystyrene (PS) by radical polymerization, which was combined with Rh to form heterogeneous chiral Rh complexes (PS-diene Rh?Cl). PS-diene Rh?Cl catalyzed asymmetric arylation reactions of α,β-unsaturated carbonyl compounds (ketones, esters, and amides), nitroalkenes, and imines afforded the desired products in high yields with excellent enantioselectivities. PS-diene Rh?Cl is stable in air, can be stored for several months, and can be reused more than 10 times without any reduction of either yield or enantioselectivity. We also developed a method of activation of PS-diene Rh?Cl to generate more active species. (Figure presented.).
Steric Tuning of Sulfinamide/Sulfoxides as Chiral Ligands with C1, Pseudo-meso, and Pseudo-C2 Symmetries: Application in Rhodium(I)-Mediated Arylation
Borrego, Lorenzo G.,Recio, Rocío,álvarez, Eleuterio,Sánchez-Coronilla, Antonio,Khiar, Noureddine,Fernández, Inmaculada
supporting information, p. 6513 - 6518 (2019/08/20)
A new family of sulfinamide/sulfoxide derivatives was synthesized as chiral bidentate ligands by stereoselective additions of methylsulfinyl carbanions to N-tert-butylsulfinylimines. The new ligands, with C1, pseudo-meso, and pseudo-C2 symmetries, were successfully assayed in Rh-catalyzed additions of arylboronic acids to activated ketones. The sterically dissymmetric C1 ligand (RS,SC,RS)-N-[1-(phenylsulfinyl)-3-methylbut-2-yl] tert-butylsulfinamide turned out to be the optimal one, allowing the 1,4-additions of diverse arylboronic acids, on different α,β-unsaturated cyclic ketones with high chemical yields and enantioselectivities up to >99% ee.
