- 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
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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.
- Bieliūnas, Vidmantas,Ston?ius, Sigitas
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p. 3815 - 3823
(2021/07/28)
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- C1-Symmetric Binap Derivative Featuring Single Diferrocenylphosphino-Donor Moiety
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A C1-symmetric chiral bisphosphine, FcPh-Binap (1), which possesses a single diferrocenylphosphino moiety together with a conventional Ph2P-substituent, was prepared in enantiomerically pure forms. Ligand 1 is sterically less demanding than Fc-Segphos (A)
- Enomoto, Yuuki,Ichiryu, Hiroki,Hu, Hao,Ura, Yasuyuki,Ogasawara, Masamichi
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supporting information
p. 1020 - 1024
(2021/05/07)
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- Enantioselective Reductive Homocoupling of Allylic Acetates Enabled by Dual Photoredox/Palladium Catalysis: Access to C2-Symmetrical 1,5-Dienes
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Transition-metal-catalyzed reductive coupling reactions have emerged as powerful protocols to construct C-C bonds. However, the development of enantioselective C(sp3)-C(sp3) reductive coupling remains challenging. Herein, we report a highly regio-, diastereo-, and enantioselective reductive homocoupling of allylic acetates through cooperative palladium and photoredox catalysis using diisopropylethylamine or Hantzsch ester as a homogeneous organic reductant. This straightforward protocol enables the stereoselective construction of C(sp3)-C(sp3) bonds under mild reaction conditions. A series of C2-symmetrical chiral 1,5-dienes were easily prepared with excellent enantioselectivities (up to >99% ee), diastereoselectivities (up to >95:5 dr), and regioselectivities (up to >95:5 rr). The resultant chiral 1,5-dienes can be directly used as chiral ligands in asymmetric synthesis, and they can be also transformed into other valuable chiral ligands.
- Zhang, Hong-Hao,Tang, Menghan,Zhao, Jia-Jia,Song, Changhua,Yu, Shouyun
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supporting information
p. 12836 - 12846
(2021/08/30)
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- Asymmetric Synthesis of Chiral Bicyclo[2.2.1]hepta-2,5-diene Ligands through Rhodium-Catalyzed Asymmetric Arylative Bis-cyclization of a 1,6-Enyne
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A series of novel chiral diene ligands (1R,4S)-L1, which are based on the bicyclo[2.2.1]heptadiene skeleton and are substituted with methyl and an ester group at the bridgehead carbons, were synthesized through rhodium-catalyzed asymmetric arylative bis-c
- Chen, Chen,Hayashi, Tamio,Meng, He,Ming, Jialin,Sun, Chao,Wei, Haili
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supporting information
p. 6311 - 6315
(2021/09/02)
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- Chiral N-aryl tert-butanesulfinamide-olefin ligands for rhodium-catalyzed asymmetric 1,4-addition of aryl boronic acids to cyclic enones
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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
- Yuan, Shuai,Zeng, Qingle,Wang, Jiajun,Zhou, Lihong
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supporting information
p. 32 - 42
(2021/02/09)
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- Synthesis of Silicon-Stereogenic Silanols Involving Iridium-Catalyzed Enantioselective C-H Silylation Leading to a New Ligand Scaffold
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Despite a growing focus on the construction of highly enantioenriched silicon-stereogenic organosilicon compounds, the enantioselective synthesis of silicon-stereogenic silanols through asymmetric catalysis remains a considerable challenge. Herein, we realized enantioselective construction of silicon-stereogenic diarylsilanols via an Ir-catalyzed C-H silylation of diarylsilanols along with stereospecific substitution or Tamao-Fleming oxidation. This strategy gives rise to a class of chiral diol catalyst cores (PSiOLs). Transformation of PSiOLs led to the ligand possessing both Si and P-stereocenters, which is capable of inducing excellent enantioselectivity in the rhodium(I)-catalyzed conjugate 1,4-addition of aryl boronic acids to cyclohexenone.
- Zhang, Hongpeng,Zhao, Dongbing
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p. 10748 - 10753
(2021/09/02)
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- Enantioselective Hydrogenation of Endocyclic Enones: the Solution to a Historical Problem?
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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.
- Lang, Qiwei,Yang, Huaxin,Gu, Guoxian,Feng, Qiang,Wen, Jialin,Zhang, Xumu
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p. 933 - 936
(2021/03/03)
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- Enantioselective Conjugate Addition of Stabilized Arylzinc Iodide to Enones: an Improved Protocol of the Hayashi Reaction
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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
- Casotti, Gianluca,Rositano, Vincenzo,Iuliano, Anna
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p. 1126 - 1131
(2020/12/17)
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- Counterion Enhanced Organocatalysis: A Novel Approach for the Asymmetric Transfer Hydrogenation of Enones
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We present a novel strategy for organocatalytic transfer hydrogenations relying on an ion-paired catalyst of natural l-amino acids as main source of chirality in combination with racemic, atropisomeric phosphoric acids as counteranion. The combination of a chiral cation with a structurally flexible anion resulted in a novel chiral framework for asymmetric transfer hydrogenations with enhanced selectivity through synergistic effects. The optimized catalytic system, in combination with a Hantzsch ester as hydrogen source for biomimetic transfer hydrogenation, enabled high enantioselectivity and excellent yields for a series of α,β-unsaturated cyclohexenones under mild conditions. Moreover, owing to the use of readily available and chiral pool-derived building blocks, it could be prepared in a straightforward and significantly cheaper way compared to the current state of the art.
- Scharinger, Fabian,Márk Pálv?lgyi, ádám,Zeindlhofer, Veronika,Schnürch, Michael,Schr?der, Christian,Bica-Schr?der, Katharina
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p. 3776 - 3782
(2020/06/22)
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- 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
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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.
- Korenaga, Toshinobu,Kori, Hiroto,Asai, Shota,Kowata, Ryo,Shirai, Masayuki
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p. 6059 - 6066
(2020/10/28)
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- Synthesis, Characterization, and Application of Segphos Derivative Having Diferrocenylphosphino-Donor Moieties
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An axially chiral bisphosphine, Fc-Segphos (1), which possesses diferrocenylphosphino-donor moieties, was prepared as a racemate, and its optical resolution was achieved by the use of chiral HPLC. Ligand 1 coordinated to a palladium(II) cation in a bidentate fashion to construct a unique chiral environment at the palladium center due to the sterically demanding ferrocenyl groups. Ligand (R)-1 was applied in the palladium-catalyzed asymmetric synthesis of axially chiral allenes showing good enantioselectivity of up to 92% ee. In general, (R)-1 displayed better enantioselectivity than the parent Segphos in the palladium-catalyzed reaction, and the Pd/(R)-1 species showed up to 18% ee enhancement over the (R)-Segphos-derived palladium catalyst.
- Hu, Hao,Ichiryu, Hiroki,Nakajima, Kiyohiko,Ogasawara, Masamichi,Ohki, Yasuhiro,Seki, Naoki
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- trans-Cyclooctenes as Chiral Ligands in Rhodium-Catalyzed Asymmetric 1,4-Additions
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trans-Cyclooctenes serve as asymmetric ligands for the rhodium-catalyzed 1,4-additions of organotin reagents to enones. We demonstrate, for the first time, that these chiral olefins can provide efficient coordination spheres for asymmetric metal catalysis. As the asymmetric environment around the reaction site is constructed by the trans-cyclooctene framework, the introduction of a substituent at the allylic position further improves enantioselectivity to 93 % ee. These findings provide new chiral framework designs for the asymmetric ligands of metal catalysts.
- Nagano, Tagui,Einaru, Shunsuke,Shitamichi, Kenta,Asano, Keisuke,Matsubara, Seijiro
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supporting information
p. 7131 - 7133
(2020/09/11)
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- Tricyclic Sulfoxide-Alkene Hybrid Ligands for Chiral Rh(I) Complexes: The "Matched" Diastereomer Catalyzes Asymmetric C-C Bond Formations
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Deprotonation of phenyldibenzo[b,f]tropylidene (8) with LDA/t-BuOK followed by quenching with either diastereomer of inexpensive glucose-based t-Bu-sulfinate (R)- or (S)-11 affords a sulfoxide-alkene hybrid ligand as the diastereomeric pairs (SS,SC)-9/(SS,RC)-10 and (RS,RC)-9/(RS,SC)-10, respectively, which via chromatographic/recrystallization may be separated into the four isomers. The optically pure diastereomeric ligands (SS,SC)-9 and (SS,RC)-10 react with [RhCl(coe)2]2 to form the dinuclear complexes (RS,SC)-11 and (RS,RC)-12, respectively, in which the bidentate ligands coordinate the metal centers through the sulfur and alkene donor functions. These complexes catalyze the conjugate addition of arylboronic acids to cyclic Michael acceptors with enantioselectivities of up to 99% ee. DFT calculations show the preponderant influence of planar chirality of the ligand alkene function. The enantioselectivity switch observed between (RS,SC)-11 and (RS,RC)-12 is explained by the inverted cis-trans coordinations of the substrate molecules in catalytic steps.
- Nikol, Alexander,Zhang, Ziyun,Chelouan, Ahmed,Falivene, Laura,Cavallo, Luigi,Herrera, Alberto,Heinemann, Frank W.,Escalona, Ana,Frie?, Sibylle,Grasruck, Alexander,Dorta, Romano
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supporting information
p. 1348 - 1359
(2020/03/30)
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- Design, synthesis and application of pinenyl chiral olefin and carbene ligand
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The invention discloses design, synthesis and application of pinenyl chiral olefin and carbene ligands. According to the carbene ligand, pinene or 9-anthraceneformaldehyde is taken as a chiral source,a corresponding bromide is obtained through a two-step reaction, then benzimidazole is taken as an initial raw material, reacts with one molecule of bromide and then reacts with the other molecule ofbromide to form a salt, and corresponding pinenyl chiral olefin and carbene ligands are obtained; the carbene ligand is used as a chiral catalyst to perform asymmetric 1, 4-addition reaction, and hasfavorable selectivity.
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-
Paragraph 0072-0076
(2020/11/10)
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- C-H Functionalization Approach for the Synthesis of Chiral C2-Symmetric 1,5-Cyclooctadiene Ligands
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Chiral cyclooctadiene (COD) derivatives are readily prepared by rhodium-catalyzed allylic C-H functionalization of COD. Either mono- or difunctionalization of COD is possible generating the products in high yield, diastereoselectivity and enantioselectivi
- Zhang, Bowen,Hollerbach, Michael R.,Blakey, Simon B.,Davies, Huw M. L.
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supporting information
p. 9864 - 9868
(2019/12/24)
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- Heterogeneous Chiral Diene-Rh Complexes for Asymmetric Arylation of α,β-Unsaturated Carbonyl Compounds, Nitroalkenes, and Imines
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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.).
- Kuremoto, Tatsuya,Yasukawa, Tomohiro,Kobayashi, Shū
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supporting information
p. 3698 - 3703
(2019/07/12)
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- Heterogeneous Rh and Rh/Ag bimetallic nanoparticle catalysts immobilized on chiral polymers
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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.
- Min, Hyemin,Miyamura, Hiroyuki,Yasukawa, Tomohiro,Kobayashi, Shu
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p. 7619 - 7626
(2019/08/20)
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- Steric Tuning of Sulfinamide/Sulfoxides as Chiral Ligands with C1, Pseudo-meso, and Pseudo-C2 Symmetries: Application in Rhodium(I)-Mediated Arylation
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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.
- Borrego, Lorenzo G.,Recio, Rocío,álvarez, Eleuterio,Sánchez-Coronilla, Antonio,Khiar, Noureddine,Fernández, Inmaculada
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supporting information
p. 6513 - 6518
(2019/08/20)
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- Enantioselective Conjugate Addition of Aryl Halides and Triflates to Electron-Deficient Olefins via Nickel- And Rhodium-Catalyzed Sequential Relay Reactions
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Asymmetric conjugate addition of aryl halides or aryl triflates to electron-deficient olefins was realized by sequential Miyaura borylation and Hayashi-Miyaura conjugate addition in one pot. A nickel-catalyzed borylation of aryl halides or triflates and a rhodium-chiral diene complex catalyzed enantioselective conjugate addition was executed as a pair of relay reactions as a more efficient and greener protocol.
- Fan, Chenrui,Wu, Qixu,Zhu, Chengfeng,Wu, Xiang,Li, Yougui,Luo, Yunfei,He, Jian-Bo
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supporting information
p. 8888 - 8892
(2019/10/14)
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- Asymmetric Baeyer-Villiger oxidation: Classical and parallel kinetic resolution of 3-substituted cyclohexanones and desymmetrization of: Meso -disubstituted cycloketones
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Regioselectivity is a crucial issue in Baeyer-Villiger (BV) oxidation. To date, few reports have addressed asymmetric BV oxidation of 3-substituted cycloketones due to the high difficulty of controlling regio- and stereoselectivity. Herein, we report the asymmetric BV oxidation of 3-substituted and meso-disubstituted cycloketones with chiral N,N′-dioxide/Sc(iii) catalysts performed in three ways: classical kinetic resolution, parallel kinetic resolution and desymmetrization. The methodology was applied in the total and formal synthesis of bioactive compounds and natural products. Control experiments and calculations demonstrated that flexible and adjustable catalysts played a significant role in the chiral recognition of substrates.
- Wu, Wangbin,Cao, Weidi,Hu, Linfeng,Su, Zhishan,Liu, Xiaohua,Feng, Xiaoming
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p. 7003 - 7008
(2019/07/31)
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- Synthesis of Highly Enantioenriched Propelladienes and their Application as Ligands in Asymmetric Rh-Catalyzed 1,4-Additions
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The first synthesis of highly enantioenriched [4.3.3]propelladienes is reported. The novel bridged bicyclo[3.3.0] dienes were applied as steering ligands in the rhodium-catalyzed asymmetric arylation of cyclic enones. The catalytic system showed high catalytic activity, and the 1,4-adducts were obtained in good to excellent yields (46-99%) with enantioselectivities up to 96% ee.
- Pecchioli, Tommaso,Christmann, Mathias
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supporting information
p. 5256 - 5259
(2018/09/13)
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- Electronic and Steric Tuning of an Atropisomeric Disulfoxide Ligand Motif and Its Use in the Rh(I)-Catalyzed Addition Reactions of Boronic Acids to a Wide Range of Acceptors
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A novel chiral disulfoxide ligand pair bearing fluorine atoms at the 6 and 6′ position of its atropisomeric backbone, (M,S,S)- and (P,S,S)-p-Tol-6F-BIPHESO, was synthesized. Complexation to a rhodium(I) precursor gave rise to μ-Cl- and μ-OH-bridged rhodiu
- Zhao, Guang-Zhen,Foster, Daven,Sipos, Gellért,Gao, Pengchao,Skelton, Brian W.,Sobolev, Alexandre N.,Dorta, Reto
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p. 9741 - 9755
(2018/09/06)
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- A diastereomeric pair of sulfoxide-containing chiral MOP-type ligands: Preparation and application to rhodium-catalyzed asymmetric 1,4-addition reactions
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(R,SS)-Sulfoxide-MOP (L2) and (R,RS)-sulfoxide-MOP (L3) were developed as a diastereomeric pair of sulfoxide-containing chiral MOP-type ligands. These two ligands also represent the first monosulfoxide analogues of BINAP. The chiral ligand L2 was successfully applied to the highly enantioselective rhodium-catalyzed 1,4-addition between α,β-unsaturated ketones or esters and arylboronic acids, and exhibited a broad substrate scope when the reaction was performed using 1.5 mol% Rh in cyclohexane/H2O (10:1) at 40 °C under mild basic conditions.
- Hoshi, Takashi,Fujita, Masataka,Matsushima, Shouta,Hagiwara, Hisahiro,Suzuki, Toshio
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supporting information
p. 800 - 802
(2018/06/12)
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- Aqueous Asymmetric 1,4-Addition of Arylboronic Acids to Enones Catalyzed by an Amphiphilic Resin-Supported Chiral Diene Rhodium Complex under Batch and Continuous-Flow Conditions
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A rhodium-chiral diene complex immobilized on amphiphilic polystyrene-poly(ethylene glycol) (PS-PEG) resin (PS-PEG-diene?-Rh) has been developed. The immobilized rhodium-chiral diene complex (PS-PEG-diene?-Rh) efficiently catalyzed the asymmetric 1,4-addition of various arylboronic acids to cyclic or linear enones in water under batch conditions to give the corresponding β-arylated carbonyl compounds in excellent yields and with excellent enantioselectivity. The catalyst was readily recovered by simple filtration and reused 10 times without loss of its catalytic activity and enantioselectivity. Moreover, a continuous-flow asymmetric 1,4-addition in a flow reactor containing PS-PEG-diene?-Rh proceeded efficiently at 50 °C with retention of high enantioselectivity. Long-term continuous-flow asymmetric 1,4-addition during 12 h readily gave the desired product on a 10 g scale with high enantioselectivity.
- Shen, Guanshuo,Osako, Takao,Nagaosa, Makoto,Uozumi, Yasuhiro
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p. 7380 - 7387
(2018/07/29)
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- A novel, C2-symmetric, chiral bis-cyclosulfinamide-olefin tridentate ligand in Rh-catalyzed asymmetric 1,4-additions
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A C2-symmetric, chiral bis-cyclosulfinamide-olefin ligand composed of two 1-oxo-2,3-dihydro-1,2-benzisothiazole moieties with rigid skeletons and a conformationally flexible butenylene chain is disclosed for the first time. HRMS and 1/sup
- Zhang, Li,Tan, Mingchao,Zhou, Lihong,Zeng, Qingle
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supporting information
p. 2778 - 2783
(2018/06/11)
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- Control of Enantioselectivity in Rhodium(I) Catalysis by Planar Chiral Dibenzo[a,e]cyclooctatetraenes
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Planar chiral 5,11-disubstiuted dibenzo[a,e]cyclo-octatetraenes (dbCOTs) have been developed as the first useful chiral homologs to dbCOT-ligands for asymmetric applications. Methods enabling the preparation of such compounds on a gram-scale in enantiomerically pure form are described. Evaluated as ligands in rhodium(I)-catalyzed 1,4- and 1,2-arylation reactions, tertiary and quarternary stereogenic centers were formed with excellent yields and selectivities of up to >99 % ee. A catalytic asymmetric synthesis of a key cyclization precursor to (?)-penifulvin A highlights the system in an applied context.
- Melcher, Michaela-Christina,Iv?i?, Trpimir,Olagnon, Charlotte,Tenten, Christina,Lützen, Arne,Strand, Daniel
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supporting information
p. 2344 - 2348
(2017/12/26)
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- Role of Regioisomeric Bicyclo[3.3.0]octa-2,5-diene Ligands in Rh Catalysis: Synthesis, Structural Analysis, Theoretical Study, and Application in Asymmetric 1,2- and 1,4-Additions
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In order to study the impact of regioisomeric diene ligands on the formation and catalytic activity of Rh complexes, a series of C2- and CS-symmetric 2,5-disubstituted bicyclo[3.3.0]octa-2,5-dienes C2-L and CS-L, respectively, were synthesized from Weiss diketone by simultaneous deprotonation/electrophilic trapping of both oxo functions, and the catalytic behavior was studied in the presence of [RhCl(C2H4)2]2. Complexes [RhCl(C2-L)]2 bearing C2-symmetric ligands catalyzed effectively the asymmetric arylation of N-tosylaldimines to (S)-diarylamines with yields and ee values up to 99%. In Hayashi-Miyaura reactions, however, the complexes showed poor catalytic activity. When complexes [RhCl(CS-L)]2 with CS-symmetric ligand or mixtures of [RhCl(C2-L)]2 and [RhCl(CS-L)]2 were employed in 1,2-additions, racemic addition products were observed, suggesting a C=C isomerization of the diene ligands. X-ray crystal structure analysis of both Rh complexes formed from the [RhCl(C2H4)2]2 precursor and ligands C2-L and CS-L revealed that only the C2-symmetric ligand C2-L coordinated to the Rh, whereas CS-L underwent a Rh-catalyzed C=C isomerization to rac-C2-L, which then gave the racemic [RhCl(rac-C2-L)]2 complex. DFT calculations of the relative stabilities of the Rh complexes and the proposed intermediates provided a mechanistic rationale via Rh-mediated hydride transfer.
- Mühlh?user, Tina,Savin, Alex,Frey, Wolfgang,Baro, Angelika,Schneider, Andreas J.,D?teberg, Heinz-Günter,Bauer, Florian,K?hn, Andreas,Laschat, Sabine
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p. 13468 - 13480
(2017/12/26)
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- Novel MOP-type H8-binaphthyl monodentate phosphite ligands and their applications in transition metal-catalyzed asymmetric 1,4-conjugate additions and hydroformylations
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A new series of monodentate phosphites based on the rigid, axially chiral monoesterified H8-BINOL, which are easy to prepare from the readily accessible phosphorylating reagents (Sa)- or (Ra)-1,1′-binaphthyl-2,2′-diylchlorophosphite and (Sa)- or (Ra)-1,1′-H8-binaphthyl-2,2′-diylchlorophosphite, have been synthesized. All ligands were purified on a silica gel column under a nitrogen atmosphere with moderate yields, and were white solids and air-stable at room temperature. These ligands afforded good to excellent enantioselectivities in the Cu-catalyzed 1,4-conjugate addition of 2-cyclohexenone with nucleophiles Et2Zn (96% ee) and with Ph2Zn (65% ee), 2-cyclopentenone with Et2Zn (95% ee), 2-cycloheptenone with Et2Zn (76% ee), and 5,6-dihydro-2H-pyran-2-one with Et2Zn (90% ee). In the Rh-catalyzed asymmetric hydroformylation of styrene, these ligands showed a chemoselectivity of >99% in aldehydes, and a satisfactory branched over linear ratio (96/4). Moreover, the sense of the enantiodiscrimination of the products was mainly determined by the configuration of the BINOL-based or H8-BINOL-based phosphocycle.
- Tian, Mi,Pang, Zeng-bo,Li, Hai-feng,Wang, Lai-lai
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supporting information
p. 330 - 337
(2017/02/18)
-
- Center chirality-axial chirality electron deficiency diphosphine ligand as well as synthesis and application thereof
-
The invention discloses a center chirality-axial chirality electron deficiency diphosphine ligand as well as synthesis and application thereof. The electron deficiency diphosphine ligand is designed and synthesized by the following steps: by basing bis(di
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-
Paragraph 0037-0039
(2017/07/20)
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- Design and synthesis of chiral 1,10-phenanthroline ligand, and application in palladium catalyzed asymmetric 1,4-addition reactions
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Pd-catalyzed asymmetric 1,4-addition of phenylboronic acid to α,β-unsaturated carbonyl compounds was developed using chiral 1,10-phenanthroline derivative as ligand. Good yields (up to 97%), and high enantioselectivities (up to 97% ee) were achieved.
- Tamura, Masafumi,Ogata, Hayato,Ishida, Yuu,Takahashi, Yasunori
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supporting information
p. 3808 - 3813
(2017/09/15)
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- Reducing Diastereomorphous Bis(phosphane oxide) Atropisomers to One Atropisomerically Pure Diphosphane: A New Ligand and a Novel Ligand-Preparation Design
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1,1′-Biphenyl-2,2′-diphosphanes with an achiral bridge spanning C-5 and C-5′ form atropisomers that are enantiomers. Accessing them in an atropisomerically pure form requires resolving a racemic mixture thereof or of a bis(phosphane oxide) precursor. 1,1′-Biphenyl-2,2′-diphosphanes with a homochiral bridge spanning C-5 and C-5′ form atropisomers that are diastereomers. We synthesized the first compound of this kind 1) atropselectively and 2) under thermodynamic control—seemingly a first-time exploit in diphosphane synthesis. The selectivity-inducing step was a high-temperature reduction of two non-interconverting bis(phosphane oxide) atropisomers (60:40 mixture). It furnished the desired diphosphane atropisomerically pure (and atropconvergently because the yield was 67 %). This diphosphane proved worthwhile in Tsuji–Trost allylations, the Hayashi addition of phenylboronic acid to cyclohexenone, and the asymmetric hydrogenation of methyl acetoacetate (up to 95 % yield and 95 % ee).
- Sartorius, Frank,Trebing, Marc,Brückner, Charlotte,Brückner, Reinhard
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supporting information
p. 17463 - 17468
(2017/11/27)
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- Pd NPs-Loaded Homochiral Covalent Organic Framework for Heterogeneous Asymmetric Catalysis
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We herein report the fabrication of a palladium nanoparticles (Pd NPs) loaded homochiral covalent organic framework using S-(+)-2-methylpiperazine and cyanuric chloride (Pd@CCOF-MPC) (2) via a very facile chemical approach. The chiral COF support of 1 (CC
- Ma, Hui-Chao,Kan, Jing-Lan,Chen, Gong-Jun,Chen, Cheng-Xia,Dong, Yu-Bin
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p. 6518 - 6524
(2017/08/18)
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- Palladium-Catalyzed Direct β-C?H Arylation of Ketones with Arylboronic Acids in Water
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A palladium-catalyzed direct β-C?H arylation of ketones was developed under mild conditions in water, featuring commercially available arylboronic acids as nucleophilic aryl sources and o-iodoxybenzoic acid as the oxidant. The method provides a concise route to access β-arylated ketones. Preliminary studies indicated that direct asymmetric β-C?H arylation of ketones could be achieved by this strategy. (Figure presented.).
- Hu, Xiaoyun,Yang, Xiaobo,Dai, Xi-Jie,Li, Chao-Jun
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supporting information
p. 2402 - 2406
(2017/07/22)
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- Chiral ferrocene-based P,S ligands for Ir-catalyzed hydrogenation of minimally functionalized olefins. Scope and limitations
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A family of 12 modular ferrocenyl planar chiral phosphine-thioethers (P,S) has been studied in the asymmetric hydrogenation of minimally functionalized alkenes. These ligands differ by the substituent on sulfur or by the linker between the ferrocene moiety and the sulfur atom (no linker, methylene or methyl substituted methylene linker bearing an additional element of chirality). The cationic iridium(cod) complexes of the different P,S ligands have been efficiently synthesized. For the majority of the ligands, coordination yielded only a single diastereoisomer with full control of the absolute configuration on sulfur. The different iridium complexes have been used in the hydrogenation of various di, tri, and tetrasubstituted minimally functionalized olefins. Conversions and enantioselectivities are highly dependent on the ligand and substrate structure. Full conversions and low-to-excellent enantioselectivities could be obtained (maximum ee from 14 to 94% for 1,1-disubsituted alkenes, from 17 to 99% for trisubstituted olefins, and 34% for the tetrasubstituted alkene).
- Biosca, Maria,Coll, Mercè,Lagarde, Florian,Brémond, Emma,Routaboul, Lucie,Manoury, Eric,Pàmies, Oscar,Poli, Rinaldo,Diéguez, Montserrat
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p. 2623 - 2631
(2015/03/30)
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- Synthesis of novel cyclohexanediol-derived chiral phosphite ligands and their application in the Cu-catalyzed conjugate addition of organozinc to cyclic enones
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A series of novel chiral diphosphite ligands have been synthesized from (1R,2R)-trans-1,2-cyclohexanediol, (1S,2S)-trans-1,2-cyclohexanediol, racemic trans-1,2-cyclohexanediol and chlorophosphoric acid diary ester, and were successfully employed in the Cu
- Pang, Zeng-Bo,Li, Hai-Feng,Wang, Lai-Lai
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supporting information
p. 271 - 276
(2018/03/22)
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- Electronically deficient (Rax,S,S)-F12-C3-TunePhos and its applications in asymmetric 1,4-addition reactions
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A novel electronically deficient chiral diphosphine ligand (Rax,S,S)-F12-C3-TunePhos has been concisely synthesized. The electron-poor ligand features both chiral centers and chiral axis bearing fluoro-functional groups on
- Hu, Shu-Bo,Chen, Zhang-Pei,Zhou, Ji,Zhou, Yong-Gui
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supporting information
p. 1925 - 1929
(2016/04/19)
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- Two phenyls are better than one or three: Synthesis and application of terminal olefin-oxazoline (TOlefOx) ligands
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A novel terminal olefin-oxazoline ligand was introduced into rhodium-catalyzed asymmetric conjugate addition of arylboronic acids to enones and gave excellent enantioselectivities. The two phenyls proved better than one or three in ligand evaluations.
- Zhao, Yi-Shuang,Liu, Jian-Kang,He, Zhi-Tao,Tao, Jing-Chao,Tian, Ping,Lin, Guo-Qiang
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supporting information
p. 3686 - 3689
(2016/05/09)
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- Base-Free Conditions for Rhodium-Catalyzed Asymmetric Arylation to Produce Stereochemically Labile α-Aryl Ketones
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The asymmetric arylation of 2,2-dialkyl cyclopent-4-ene-1,3-diones with aryl boronic acids was found to be efficiently catalyzed by a chiral diene-rhodium μ-chloro dimer, [{RhCl((R)-diene?)}2], in the absence of bases in toluene/H2O to give 2,2-dialkyl 4-aryl cyclopentane-1,3-diones in high yields with high enantioselectivity. Such compounds can not be obtained with high enantiomeric purity under the standard basic conditions used for rhodium-catalyzed asymmetric arylation because the α-aryl ketone products undergo racemization under the basic conditions. Forget about bases, score a home run: The asymmetric arylation of 2,2-dialkyl cyclopent-4-ene-1,3-diones with aryl boronic acids was efficiently catalyzed by a chiral diene-rhodium μ-chloro dimer without a base in toluene/H2O (see scheme). The resulting α-aryl ketones can not be obtained with high ee values under the standard basic conditions for rhodium-catalyzed asymmetric arylation owing to their racemization in the presence of a base.
- Dou, Xiaowei,Lu, Yixin,Hayashi, Tamio
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supporting information
p. 6739 - 6743
(2016/06/09)
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- Synthesis and evaluation of C2-symmetric bis-sulfinamides as effective ligands in rhodium catalyzed addition of arylboronic acids to cycloalkenones
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Synthesis of novel C2-symmetric 1,2- 1,3- and 1,4- bis-sulfinamides and their use as effective ligands in rhodium (I) catalyzed asymmetric conjugate addition of arylboronic acids to cyclohexenone and cyclopentenones is described. C2-
- Revu, Omkar,Uphade, Manoj B.,Prasad, Kavirayani R.
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p. 5355 - 5362
(2016/08/05)
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- Kinetic Resolution of Planar-Chiral Ferrocenylphosphine Derivatives by Molybdenum-Catalyzed Asymmetric Ring-Closing Metathesis and Their Application in Asymmetric Catalysis
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Highly enantioselective kinetic resolution of racemic planar-chiral metallocenylphosphine sulfides was realized by the molybdenum-catalyzed asymmetric ring-closing metathesis reaction with the krel values of up to 147. The enantiomerically enriched 1,4-but-2-enylene-bridged ferrocenylphosphine sulfides thus obtained could be purified to enantiomerically pure forms by simple recrystallization from hot methanol, and subsequent reduction of the phosphine sulfides provided the corresponding planar-chiral phosphines with retention of the enantiomeric homogeneity. This is a rare example of preparing planar-chiral ferrocenylphosphines by catalytic asymmetric reactions. The single-enantiomer planar-chiral ferrocenylphosphines were applied as chiral ligands in the rhodium-catalyzed asymmetric 1,4-addition reaction (the Hayashi-Miyaura conjugate addition reaction) of phenylboronic acid to 2-cyclohexenone to show excellent enantioselectivity and high yields. The NMR studies clarified that the butenylene-bridged ferrocenylphosphine coordinated to a rhodium(I) cation in a monodentate fashion and an interaction of the bridging olefin moiety to the rhodium atom was not detected.
- Ogasawara, Masamichi,Arae, Sachie,Watanabe, Susumu,Nakajima, Kiyohiko,Takahashi, Tamotsu
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p. 1308 - 1315
(2016/02/18)
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- A New Type of Chiral Cyclic Sulfinamide–Olefin Ligands for Rhodium-Catalyzed Asymmetric Addition
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A new type of chiral cyclic sulfinamide–olefin ligands, N-allylic 2,3-dihydro-1,2-benzoisothiazole 1-oxides, with 2,3-dihydro-1,2-benzoisothiazole 1-oxide as a unique chiral skeleton, is developed for the highly enantioselective rhodium-catalyzed asymmetr
- Wen, Quan,Zhang, Li,Xiong, Jing,Zeng, Qingle
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supporting information
p. 5360 - 5364
(2016/11/22)
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- Chiral Bicyclic Bridgehead Phosphoramidite (Briphos) Ligands for Asymmetric Rhodium-Catalyzed 1,2- and 1,4-Addition
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A complementary solution for Rh-catalyzed enantioselective 1,2- and 1,4-arylation with two structurally related chiral ligands is reported. A chiral bicyclic bridgehead phosphoramidite (briphos) ligand derived from 1-aminoindane was efficient for the 1,2-arylation of N-sulfonyl imines, while that derived from 1,2,3,4-tetrahydro-1-naphthylamine was efficient for 1,4-arylation of α,β-unsaturated cyclic ketones. For α,β-unsaturated N-tosyl ketimines, the briphos derived from 1-aminoindane was found to selectively provide γ, γ-diaryl N-tosyl enamines with high yields and stereoselectivities.
- Lee, Ansoo,Kim, Hyunwoo
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p. 3520 - 3527
(2016/05/24)
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- Chiral Phosphorus-Olefin Ligands for the RhI-Catalyzed Asymmetric Addition of Aryl Boronic Acids to Electron-Deficient Olefins
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New chiral phosphorus-olefin hybrid ligands derived from the rigid "privileged" l-proline have been conveniently prepared and applied in the rhodium-catalyzed asymmetric arylation of electron-deficient olefins with arylboronic acids at room temperature; t
- Chen, Qian,Li, Liang,Zhou, Guangli,Ma, Xiaoli,Zhang, Lu,Guo, Fang,Luo, Yi,Xia, Wujiong
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supporting information
p. 1518 - 1522
(2016/06/01)
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- Synthesis of atropisomeric chiral MeOBIPHEP analogues via Pd-catalyzed P-C coupling - applications to asymmetric Rh-catalyzed C-C bond formations in water
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Abstract The preparation and catalytic applications of water-soluble MeOBIPHEP-based atropisomeric chiral congener ligands are described. The optimization of the catalytic system to promote the key P-C coupling revealed the superiority of palladium cataly
- Leseurre, Lucie,Le Boucher D'Herouville, Florent,Millet, Anthony,Genêt, Jean-Pierre,Scalone, Michelangelo,Michelet, Véronique
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p. 129 - 132
(2015/06/23)
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- Multicomponent synthesis of chiral bidentate unsymmetrical unsaturated N-heterocyclic carbenes: Copper-catalyzed asymmetric C-C bond formation
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A multicomponent strategy was applied to the synthesis of chiral bidentate unsaturated hydroxyalkyl- and carboxyalkyl-N-heterocyclic carbene (NHC) precursors. The newly developed low-cost chiral ligands derived from amino alcohols and amino acids were eva
- Jahier-Diallo, Claire,Morin, Marie S. T.,Queval, Pierre,Rouen, Mathieu,Artur, Isabelle,Querard, Pierre,Toupet, Loic,Cr??visy, Christophe,Basl??, Olivier,Mauduit, Marc
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supporting information
p. 993 - 997
(2015/02/05)
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- 4,8-disubstituted bicyclo[3.3.1]nona-2,6-dienes as chiral ligands for rh-catalyzed asymmetric 1,4-addition reactions
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C2-symmetric chiral diene ligands based on 4,8-endo,endo-disubstituted bicyclo[3.3.1]nona-2,6-diene framework have been designed and synthesized. The rhodium complexes of the dienes, which were obtained in a few straightforward steps from enantiomerically pure bicyclo[3.3.1]nonane-2,6-dione, exhibited excellent catalytic activity and high enantioselectivity (up to 96% ee) in the conjugate addition reaction of arylboronic acids to cyclic enones under mild reaction conditions with high atom efficiency. Chiral C2-symmetric 4,8-endo,endo-disubstituted bicyclo[3.3.1]nona-2,6-diene ligands were synthesized from easily available bicyclo[3.3.1]nonane-2,6-dione and utilized in the asymmetric 1,4-addition reaction of arylboronic acids to cyclic enones. The catalyst prepared in situ from ligand 4b and [RhCl(C2H4)2]2 exhibited excellent catalytic activity and high enantioselectivity (up to 96% ee) under mild reaction conditions with high atom efficiency.
- Rimkus, Renaldas,Jurgelenas, Marius,Ston?ius, Sigitas
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supporting information
p. 3017 - 3021
(2015/05/13)
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- The first chiral diene-based metal-organic frameworks for highly enantioselective carbon-carbon bond formation reactions
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We have designed the first chiral diene-based metal-organic framework (MOF), E2-MOF, and postsynthetically metalated E2-MOF with Rh(i) complexes to afford highly active and enantioselective single-site solid catalysts for C-C bond fo
- Sawano, Takahiro,Ji, Pengfei,McIsaac, Alexandra R.,Lin, Zekai,Abney, Carter W.,Lin, Wenbin
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p. 7163 - 7168
(2015/11/23)
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- Cellulose-supported chiral rhodium nanoparticles as sustainable heterogeneous catalysts for asymmetric carbon-carbon bond-forming reactions
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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.
- Yasukawa, Tomohiro,Miyamura, Hiroyuki,Kobayashi, Shu
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p. 6224 - 6229
(2015/10/28)
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- A short synthesis of (+)-β-lycorane by asymmetric conjugate addition cascade
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Abstract The chiral diether ligand-controlled asymmetric conjugate addition of organolithiums to nona-2,7-dienedioate and subsequent intramolecular conjugate addition of the enolate intermediate gave all-trans trisubstituted cyclohexanes with high ee and
- Nishimura, Katsumi,Fukuyama, Naoshi,Yasuhara, Tomohisa,Yamashita, Mitsuaki,Sumiyoshi, Takaaki,Yamamoto, Yasutomo,Yamada, Ken-Ichi,Tomioka, Kiyoshi
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p. 7222 - 7226
(2015/03/30)
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- A chiral phosphine-olefin ligand derived from l-hydroxyproline and its use in the rhodium-catalyzed asymmetric 1,4-addition
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A new chiral phosphine-olefin ligand (S)-1 has been designed and synthesized from l-hydroxyproline via a short reaction sequence. It was examined for its efficiency in the rhodium-catalyzed asymmetric addition of arylboronic acids and a phenylzinc reagent
- Gandi, Vasudeva Rao,Lu, Yixin,Hayashi, Tamio
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p. 679 - 682
(2015/08/03)
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