- The Trityl-Cation Mediated Phosphine Oxides Reduction
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Reduction of phosphine oxides into the corresponding phosphines using PhSiH3 as a reducing agent and Ph3C+[B(C6F5)4]? as an initiator is described. The process is highly efficient, reducing a broad range of secondary and tertiary alkyl and arylphosphines, bearing various functional groups in generally good yields. The reaction is believed to proceed through the generation of a silyl cation, which reaction with the phosphine oxide provides a phosphonium salt, further reduced by the silane to afford the desired phosphine along with siloxanes. (Figure presented.).
- Landais, Yannick,Laye, Claire,Lusseau, Jonathan,Robert, Frédéric
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supporting information
p. 3035 - 3043
(2021/05/10)
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- Chiral Recognition of in Situ-Oxidized Phosphine Oxides with Octahedral Indium Complexes by 31P NMR Spectroscopy
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Herein, efficient chiral recognition of phosphine oxides with octahedral indium complexes was demonstrated. Direct chiral analysis of in situ-prepared phosphine oxides formed using phosphines and hydrogen peroxide was conducted effectively via 31P nuclear magnetic resonance spectroscopy. Sufficient peak resolution of chiral phosphines was obtained consistently, thereby enabling the reliable determination of absolute chirality. Rational 1:1 binding models based on experiments and density functional theory calculations have been proposed.
- Jang, Sumin,Kim, Hyunwoo,Kwahk, Eun-Jeong
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supporting information
p. 7829 - 7833
(2021/10/12)
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- Photoresponsive Propeller-like Chiral AIE Copper(I) Clusters
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A pair of propeller-like chiral trinuclear CuI clusters (R/S-Cu3) with unique photoinduced fluorescence enhancement were prepared. R/S-Cu3 showed intense variable luminescence after UV light irradiation, which was attributed to the stepwise oxidation of ligand in the clusters. It exhibited typical aggregation-induced emission (AIE) (αAIE=17.3). Mechanism studies showed that metal cluster-centered (MCC) and triplet metal-to-ligand charge-transfer (3MLCT) processes are the origin of the luminescence; the processes are regulated by a restriction of intramolecular motions mechanism in a different state. The chiral structure and AIE feature endow R/S-Cu3 with remarkable circularly polarized luminescence (glum=2×10?2) in the aggregated state. It shows good capability for producing reactive oxygen species. This work enriches the kinds of atomically precise AIE clusters, gains insight into their luminescence mechanism, and offers the prospect of application in multifunctional materials.
- Kong, Yu-Jin,Li, Kai,Li, Si,Su, Hui-Fang,Yan, Zhi-Ping,Zang, Shuang-Quan,Zheng, You-Xuan
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p. 5336 - 5340
(2020/02/20)
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- Circularly polarized luminescence of Sm (III) and Eu (III) complexes with chiral ligand (R/S)-BINAPO
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Luminescent lanthanide (III) ions have been exploited for circularly polarized luminescence (CPL) for decades. However, very few of these studies have involved chiral samarium (III) complexes. Complexes are prepared by mixing axial chiral ligands (R/S))-2
- Cotter, Daniel,Dodder, Spencer,Klimkowski, Valentine J.,Hopkins, Todd A.
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p. 301 - 311
(2019/02/19)
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- Evaluation of bifunctional chiral phosphine oxide catalysts for the asymmetric hydrosilylation of ketimines
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A series of bifunctional phosphine oxides have been prepared and evaluated as catalysts for the trichlorosilane mediated asymmetric hydrosilylation of ketimines. bis-Phosphine oxides, hydroxy-phosphine oxides, and biaryl phosphine oxides all demonstrated good catalytic activity, but poor to moderate enantioselectivity. A bis-P-chiral phosphine oxide displayed the highest enantioselectivity of 60%.
- Warner, Christopher J.A.,Berry, Sian S.,Jones, Simon
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- An enantioselective oxidative coupling reaction of 2-naphthol derivatives catalyzed by chiral diphosphine oxide-iron(ii) complexes
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An enantioselective oxidative coupling of 2-naphthol derivatives is developed with the use of chiral Fe(ii)-diphosphine oxide complexes. Optically active 1,1-bi-2-naphthol derivatives can be synthesized in high yields when a 2?:?1 complex of (S)-xylyl-iPrO-BIPHEP-oxide and Fe(OTf)2 is used in the presence of t-butyl hydroperoxide as an oxidant. The non-linear effect, X-ray crystal structure and ESI-MS suggest that a 2?:?1 complex of (S)-xylyl-iPrO-BIPHEP-oxide and Fe(OTf)2 is a pre-catalyst for a Fe(iii)/Fe(iv) redox cycle.
- Horibe, Takahiro,Nakagawa, Keita,Hazeyama, Takashi,Takeda, Kazuki,Ishihara, Kazuaki
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supporting information
p. 13677 - 13680
(2019/11/19)
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- Chemoselective Reduction of Phosphine Oxides by 1,3-Diphenyl-Disiloxane
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Reduction of phosphine oxides to the corresponding phosphines represents the most straightforward method to prepare these valuable reagents. However, existing methods to reduce phosphine oxides suffer from inadequate chemoselectivity due to the strength of the P=O bond and/or poor atom economy. Herein, we report the discovery of the most powerful chemoselective reductant for this transformation to date, 1,3-diphenyl-disiloxane (DPDS). Additive-free DPDS selectively reduces both secondary and tertiary phosphine oxides with retention of configuration even in the presence of aldehyde, nitro, ester, α,β-unsaturated carbonyls, azocarboxylates, and cyano functional groups. Arrhenius analysis indicates that the activation barrier for reduction by DPDS is significantly lower than any previously calculated silane reduction system. Inclusion of a catalytic Br?nsted acid further reduced the activation barrier and led to the first silane-mediated reduction of acyclic phosphine oxides at room temperature.
- Buonomo, Joseph A.,Eiden, Carter G.,Aldrich, Courtney C.
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supporting information
p. 14434 - 14438
(2017/10/23)
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- Porous Rh/BINAP polymers as efficient heterogeneous catalysts for asymmetric hydroformylation of styrene: Enhanced enantioselectivity realized by flexible chiral nanopockets
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A new chiral monomer, (S)-5,5′-divinyl-BINAP, was successfully synthesized and embedded into two different porous organic polymers (Poly-1 and Poly-2). After loading a Rh species, the catalysts were applied for the heterogeneous asymmetric hydroformylation of styrene. Compared with the homogeneous BINAP analogue, the enantioselectivity of Rh/Poly-1 catalyst was drastically increased by approximately 70%. The improved enantioselectivity of the porous Rh/BINAP polymers was attributed to the presence of flexible chiral nanopockets resulting from the increased bulk of the R groups near the catalytic center.
- Wang, Tao,Wang, Wenlong,Lyu, Yuan,Xiong, Kai,Li, Cunyao,Zhang, Hao,Zhan, Zhuangping,Jiang, Zheng,Ding, Yunjie
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p. 691 - 698
(2017/04/24)
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- Two chiral ligands, and preparation and applications of chiral porous organic polymer
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The present invention provides a preparation method of two vinyl BINAP(2,2,-bis(diphenylphosphino)-1,1,-binaphthyl) derivative ligands, a preparation method of a related polymer, and applications of the related polymer as a catalyst carrier in an asymmetr
- -
-
Paragraph 0019
(2017/07/19)
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- Chiral BINAP-based hierarchical porous polymers as platforms for efficient heterogeneous asymmetric catalysis
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Two vinyl-functionalized chiral 2,2′-bis(diphenylphosphino)-1,1′-binaphthyl (BINAP) ligands, (S)-4,4′-divinyl-BINAP and (S)-5,5′-divinyl-BINAP, were successfully synthesized. Chiral BINAP-based porous organic polymers (POPs), denoted as 4-BINAP@POPs and 5-BINAP@POPs, were efficiently prepared via the copolymerization of vinyl-functionalized BINAP with divinyl benzene under solvothermal conditions. Thorough characterization using nuclear magnetic resonance spectroscopy, thermogravimetric analysis, extended X-ray absorption fine structure analysis, and high-angle annular dark-field scanning transmission electron microscopy, we confirmed that chiral BINAP groups were successfully incorporated into the structure of the materials considered to contain hierarchical pores. Ru was introduced as a catalytic species into the POPs using different synthetic routes. Systematic investigation of the resultant chiral Ru/POP catalysts for heterogeneous asymmetric hydrogenation of β-keto esters revealed their excellent chiral inducibility as well as high activity and stability. Our work thereby paves a path towards the use of advanced hierarchical porous polymers as solid chiral platforms for heterogeneous asymmetric catalysis.
- Wang, Tao,Lyu, Yuan,Xiong, Kai,Wang, Wenlong,Zhang, Hao,Zhan, Zhuangping,Jiang, Zheng,Ding, Yunjie
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p. 890 - 897
(2017/05/22)
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- Enantioselective Synthesis of 2-Bromomethyl Indolines via BINAP(S)-Catalyzed Bromoaminocyclization of Allyl Aniline
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An enantioselective bromoamination of allyl aniline with N-bromosuccinimide (NBS) catalyzed by BINAP(S) (BINAP monosulfide) is described. This protocol could provide a range of chiral 2-bromomethyl indolines in good to excellent yields with up to 87% ee.
- Yu, Sheng-Nan,Li, Yin-Long,Deng, Jun
-
supporting information
p. 2499 - 2508
(2017/07/22)
-
- Enantioselective chlorinative aldol reaction of α-substituted acroleins catalyzed by chiral phosphine oxides
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The enantioselective chlorinative aldol reaction of α-substituted acroleins with aldehydes catalyzed by chiral phosphine oxides is described. A hypervalent silicon complex-derived chloride adds to the α-substituted acroleins to form the corresponding sily
- Kotani, Shunsuke,Hanamure, Takuya,Nozaki, Hirono,Sugiura, Masaharu,Nakajima, Makoto
-
supporting information
p. 282 - 287
(2017/02/18)
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- Sequential Catalysis of Phosphine Oxide for Stereoselective Synthesis of Stereopentads
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An efficient method for accessing enantiomerically pure stereopentads via a catalytic asymmetric sequential aldol reaction has been developed for the first time. The enantioselective sequential aldol reaction produces a wide range of chiral stereopentad precursors in good yields with excellent enantioselectivities. The key to success is the use of the sequential catalytic system involving a chiral phosphine oxide catalyst and trichlorosilyl triflate.
- Kotani, Shunsuke,Kai, Kosuke,Sugiura, Masaharu,Nakajima, Makoto
-
supporting information
p. 3672 - 3675
(2017/07/15)
-
- PHOSPHEPINE MATRIX COMPOUND FOR A SEMICONDUCTING MATERIAL
-
The present invention is directed to a compound comprising at least one phosphepine ring and having the phosphorous atom of the phosphepine ring substituted with at least one monovalent substituent R, wherein (i) R is selected from aryls and heteroaryls c
- -
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Page/Page column 20; 21
(2017/01/31)
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- Chiral Ru/Ir bimetallic dendronized polymer catalysts constructed through sequential metal coordination and applied in asymmetric hydrogenation of quinaldine
-
A new kind of chiral conjugated copolymer P-2 with (S)-BINAP [BINAP = 2,2′-bis(diarylphosphino)-1,1′-binaphthyl] and fluorene as the building blocks was synthesized involving Pd[P(p-tolyl)3] 3-catalyzed Suzuki-coupling reaction together with reduction of phosphine oxide with HSiCl3/NEt3. The chiral polymer was used to construct chiral Ru/Ir bimetallic dendronized polymer catalysts P-5-m with different generations of Fréchet-type dendritic DPEN [DPEN = 1,2-diphenylethylenediamine] ligands through a programmed metal-ligand coordination strategy. These dendronized polymer catalysts were applied to the Ir-catalyzed asymmetric hydrogenation of quinaldine and exhibited excellent activity with moderate enantioselectivity. The reaction rate was increased with increasing generation of the dendronized polymer catalysts, which are better than that obtained from the monomeric catalyst. This interesting positive dendrimer effect might be due to effective shielding of the catalytically active iridium center by the bulky dendritic pendants, which reduced the formation of the inactive iridium dimer.
- Huang, Yi-Yong,Yang, Xing,Feng, Yu,Verpoort, Francis,Fan, Qing-Hua
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p. 150 - 155
(2014/07/21)
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- NIR and CT luminescence spectra of [Yb(TFN)(S-BINAPO)] and [Yb(HFA)(S-BINAPO)] complexes
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The complexes [Yb(TFN)3(S-BINAPO)](TFN = 4,4,4-trifluoro-1(2- napthyl)-1,3-butanedione) (complex 1) and [Yb(HFA)3(S-BINAPO)](HFA = hexafluoroacetylacetonate) (complex 2) were synthesized, characterized. The absorption as well as PL s
- Subhan, Md. Abdus,Nakata, Hiroyasu
-
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- 4,4′- and 5,5′-functionalized (S)- and (R)-2,2′- bis(diphenylphosphanyl)-1,1′-binaphthyl oxide derivatives
-
A series of 4, 4′- and 5, 5′-functionalized (S)- and (R)-2, 2′-bis(diphenylphosphanyl)-1, 1′-binaphthyl oxide (BINAPO) derivatives were prepared by Suzuki-Miyaura coupling from 4, 4′- and 5, 5′-dibromo-BINAPO and the corresponding boronic acid, RB(OH)sub
- Lestari, Witri Wahyu,Zaake-Hertling, Haldor,Loennecke, Peter,Hey-Hawkins, Evamarie
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supporting information
p. 2589 - 2596
(2013/11/19)
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- Facile synthesis of chiral 1,2-chlorohydrins via the ring-opening of meso-epoxides catalyzed by chiral phosphine oxides
-
The facile synthesis of chiral 1,2-chlorohydrins via the enantioselective ring-opening of meso-epoxides with silicon tetrachloride in the presence of a chiral phosphine oxide was accomplished. The chiral 1,2-chlorohydrins were also obtained from the corresponding cis-alkenes in one-pot without significant loss in the selectivity, thereby permitting easy access to the 1,2-chlorohydrins from cis-alkenes with good yields and enantioselectivities.
- Kotani, Shunsuke,Furusho, Haruka,Sugiura, Masaharu,Nakajima, Makoto
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p. 3075 - 3081
(2013/03/28)
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- Stereoselective synthesis of multiple stereocenters by using a double aldol reaction
-
Triple play: The title reaction of an alkyl methyl ketone and two aldehydes using chiral (S)-binapo as a Lewis base catalyst allows access to 1,5-dihydroxy-3-pentanone derivatives with multiple chiral centers in good yields with high diastereo- and enantioselectivities in a single operation (see scheme).
- Shimoda, Yasushi,Kubo, Tatsunori,Sugiura, Masaharu,Kotani, Shunsuke,Nakajima, Makoto
-
supporting information
p. 3461 - 3464
(2013/04/23)
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- Mesoporous cross-linked polymer copolymerized with chiral BINAP ligand coordinated to a ruthenium species as an efficient heterogeneous catalyst for asymmetric hydrogenation
-
We report here a successful preparation of a heterogeneous chiral catalyst from copolymerization of mesoporous cross-linked polymer with chiral BINAP ligands, followed by coordination of the BINAP with a ruthenium species, which exhibits high activity, excellent enantioselectivity, and extraordinary recyclability in asymmetric hydrogenation.
- Sun, Qi,Meng, Xiangju,Xiao, Feng-Shou,Liu, Xiao,Zhang, Xiaoming,Yang, Yan,Yang, Qihua
-
supporting information
p. 10505 - 10507,3
(2020/09/02)
-
- Enantioresolution of 2,2′-Bis(diphenylphosphino)-1,1′- binaphthyl oxide using inclusion complex with chiral 2,2′-dihydroxy-1, 1′-binaphtyl
-
An enantioresolution of 2,2′-bis(diphenylphosphino)-1,1′- binaphthyl oxide (BINAPO) into its enantiomers was achieved using the inclusion complex with a commerciallyavailable chiral 2,2′-dihydroxy-1,1′- binaphthyl ((R)-BINOL), giving the two enantiomers w
- Hatano, Bunpei,Hashimoto, Kazuyuki,Katagiri, Hiroshi,Kijima, Tatsuro,Murakami, Satoshi,Matsuba, Shigeru,Kusakari, Miho
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experimental part
p. 3595 - 3597
(2012/06/15)
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- Enantioselective catalysis with a chiral, phosphane-containing PMO material
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A novel bistriethoxysilyl-BINAP monomer was prepared and co-condensed with a biphenylene-bridged siloxane precursor in the presence of surfactant templates to give periodic mesoporous organosilicas (PMOs) functionalized with BINAP. Complexation of ruthenium followed by asymmetric catalytic hydrogenation and asymmetric transfer hydrogenation were carried out, and demonstrated that high levels of activity and selectivity are achievable with the chiral material.
- Seki, Tomohiro,McEleney, Kevin,Crudden, Cathleen M.
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supporting information; experimental part
p. 6369 - 6371
(2012/08/14)
-
- Simple unprecedented conversion of phosphine oxides and sulfides to phosphine boranes using sodium borohydride
-
A variety of phosphine oxides and sulfides can be efficiently converted directly to the corresponding phosphine boranes using oxalyl chloride followed by sodium borohydride. Optically active P-stereogenic phosphine oxides can be converted stereospecifically to phosphine boranes with inversion of configuration by treatment with Meerwein's salt followed by sodium borohydride.
- Rajendran, Kamalraj V.,Gilheany, Declan G.
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supporting information; body text
p. 817 - 819
(2012/02/03)
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- Enantioselective reductive aldol reaction using tertiary amine as hydride donor
-
An efficient method was developed for the enantioselective reductive aldol reaction of α,β-unsaturated ketones with aldehydes in the presence of a Lewis base catalyst; conjugate reduction using a tertiary amine and trichlorosilyl triflate, followed by an aldol reaction with BINAP dioxide (BINAPO) as an organocatalyst, gave the corresponding product in high yield with high stereoselectivity.
- Osakama, Kazuki,Sugiura, Masaharu,Nakajima, Makoto,Kotani, Shunsuke
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supporting information; body text
p. 4199 - 4201
(2012/08/28)
-
- Enantioselective double aldol reaction catalyzed by chiral phosphine oxide
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Goes on twice! The first enantioselective double aldol reaction is described (see scheme; R1=aryl, alkyl, alkenyl; R2=aryl, alkenyl). A combination of readily available chiral phosphine oxide and silicon tetrachloride as reagents enables the unique transformation, which gives the double aldol adducts in high yields and selectivities.
- Shimoda, Yasushi,Kotani, Shunsuke,Sugiura, Masaharu,Nakajima, Makoto
-
supporting information; experimental part
p. 7992 - 7995
(2011/09/13)
-
- The preparation of bi-functional organophosphine oxides as potential antitumor agents
-
Following our previously reported pyridinyl phosphine oxides as antitumor agents, we targeted the commercially available C2-axial chiral organophosphine ligand catalysts, such as 2,2′-bis(diphenylphosphino)-1, 1′-binaphthyl (BINAP) 1 and 2,2′,6
- Lam, Kim-Hung,Chui, Chung-Hin,Gambari, Roberto,Wong, Raymond Siu-Ming,Cheng, Gregory Yin-Ming,Lau, Fung-Yi,Lai, Paul Bo-San,Tong, See-Wai,Chan, Kit-Wah,Wong, Wai-Yeung,Chan, Albert Sun-Chi,Tang, Johnny Cheuk-On
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experimental part
p. 5527 - 5530
(2010/12/20)
-
- Asymmetric C-C bond-formation reaction with Pd: How to favor heterogeneous or homogeneous catalysis?
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The enantioselective allylic alkylation of (E)-1,3-diphenylallyl acetate was studied to clarify the heterogeneous or homogeneous character of the Pd/Al2O3-(R)-BINAP catalyst system. A combined approach was applied: the catalytic test
- Reimann, Sven,Grunwaldt, Jan-Dierk,Mallat, Tamas,Baiker, Alfons
-
body text
p. 9658 - 9668
(2010/10/20)
-
- Highly regioselective bromination of BINAP in [Hmim]PF6 ionic liquid
-
Bromination of (R)-2,2′-(diphenylphospnino)-1,1′-binaphthyl (BINAP) in [Hmim]PF6 ionic liquid was performed with N-halosuccinimides at 110°C during 12 h, affording the 4,4′-dibromoBINAP in high yield. The ionic liquid was recycled four times without modif
- Alame, Mohammad,Meille, Valerie,De Bellefon, Claude,Jahjah, Mohammad,Pellet-Rostaing, Stephane,Berthod,Lemaire, Marc
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p. 141 - 147
(2008/03/15)
-
- Method Of Reducing A Functional Group In An Oxidized Form
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A novel method of reducing a functional group in an oxidised form. The invention relates more particularly to the reduction of aldehyde, ketone, ester, lactone, nitrile or phosphine oxide groups. The reduction method according to the invention is characterised in that it comprises exposing the substrate including the functional group to be reduced to the presence of a siloxane-type compound of the following formula (I), combined with a Lewis acid-type catalyst. In said formula (I):—R1 and R2, which are the same or different, are an alkyl, cycloalkyle or aryl group, —X is a digit from 0 to 50.
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Page/Page column 12
(2008/12/08)
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- Selective mono reduction of bis-phosphine oxides under mild conditions
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Bis-phosphine oxides can be selectively reduced to bis-phosphine monoxides under exceptionally mild conditions using triflic anhydride and a thiol. The Royal Society of Chemistry.
- Petersson, Maria J.,Loughlin, Wendy A.,Jenkins, Ian D.
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supporting information; experimental part
p. 4493 - 4494
(2009/05/06)
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- Reduction of tertiary phosphine oxides with DIBAL-H
-
(Chemical Equation Presented) The reduction of tertiary phosphine oxides (TPOs) and sulfides with diisobutylaluminum hydride (DIBAL-II) has been studied in detail. An extensive solvent screen has revealed that hindered aliphatic ethers, such as MTBE, are optimum for this reaction at ambient temperature. Many TPOs undergo considerable reduction at ambient temperature and then stall due to inhibition. 31P and 13C NMR studies using isotopically labeled substrates as well as competition studies have revealed that the source of this inhibition is tetraisobutyldialuminoxane (TIBAO), which builds up as the reaction proceeds. TIBAO selectively coordinates the TPO starting material, preventing further reduction. Several strategies have been found to circumvent this inhibition and obtain full conversion with this extremely inexpensive reducing agent for the first time. Practical reduction protocols for these critical targets have been developed.
- Busacca, Carl A.,Raju, Ravinder,Grinberg, Nelu,Haddad, Nizar,James-Jones, Paul,Lee, Heewon,Lorenz, Jon C.,Saha, Anjan,Senanayake, Chris H.
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p. 1524 - 1531
(2008/04/12)
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- Diphosphines, preparation and uses thereof
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The invention concerns novel diphosphines of formula (I) useful in particular, in their optically active form, as ligands in metal complexes. The invention also concerns their uses an intermediates in the preparation of polymeric insoluble ligands. The invention further concerns the use of said insoluble ligands in the preparation of metal complexes for asymmetric. catalysis.
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Page/Page column 20
(2008/06/13)
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- Efficient aerobic oxidation of phosphines, phosphites, and sulfides by using trialkylborane
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Treatment of phosphines, phosphites, or sulfides with trialkylborane under air afforded the corresponding oxides in good yields.
- Motoshima, Kosuke,Sato, Akinori,Yorimitsu, Hideki,Oshima, Koichiro
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experimental part
p. 2229 - 2231
(2009/08/08)
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- Chiral phosphine oxide BINAPO as a Lewis base catalyst for asymmetric allylation and aldol reaction of trichlorosilyl compounds
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Chiral phosphine oxide BINAPO, which was readily prepared from chiral phosphine BINAP, exhibited good catalytic activities in the reaction of trichlorosilyl compounds via hypervalent silicate intermediates. The allylation of aldehydes with allyltrichloros
- Kotani, Shunsuke,Hashimoto, Shunichi,Nakajima, Makoto
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p. 3122 - 3132
(2007/10/03)
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- New perfluoroalkylated BINAP usable as a ligand in homogeneous and supercritical carbon dioxide asymmetric hydrogenation
-
New (R)- or (S)-4,4′- and 5,5′- perfluoroalkylated BINAP have been synthesized in four steps from enantiomerically pure BINAP. These new ligands were used in the homogeneous asymmetric hydrogenation of ethyl acetoacetate in ethanol and in the asymmetric hydrogenation of methyl-2-acetamidoacrylate in supercritical carbon dioxide. In the supercritical media, the addition and nature of a co-solvent have been discussed. Very good conversion and selectivity were obtained in each case.
- Berthod, Mikael,Mignani, Gerard,Lemaire, Marc
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p. 1121 - 1126
(2007/10/03)
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- 4,4′ and 5,5′-DiamBINAP as a hydrosoluble chiral ligand: Syntheses and use in Ru(II) asymmetric biphasic catalytic hydrogenation
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4,4′ and 5,5′-DiaminomethylBINAP were prepared in five steps from enantiomerically pure BINAP. Their synthesis involves, as key steps, the regioselective bromination of BINAP and the chemoselective efficient reduction of a dicyano, diphosphine oxide into the corresponding dicyano, diphosphine by a mixture of HSiCl3/PhSiH3. The ruthenium complexes of these new ligands were tested for the homogeneous and water/organic solvent biphasic asymmetric hydrogenation of β-ketoesters leading to 100% conversion with an enantiomeric excess greater than 97% in water. Catalysts can be recycled several times by extraction of the product with pentane.
- Berthod, Mikael,Saluzzo, Christine,Mignani, Gerard,Lemaire, Marc
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p. 639 - 645
(2007/10/03)
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- Stereospecific, enantioselective allylation of α-hydrazono esters by using allyltrichlorosilanes with BINAP dioxides as neutral-coordinate organocatalysts
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(Chemical equation presented). Excellent diastereo- and enantioselectivities were obtained in the title reaction, (E)-Crotylsilanes gave syn adducts, whereas anti adducts were obtained from (Z)-crotylsilanes (see scheme).
- Ogawa, Chikako,Sugiura, Masaharu,Kobayashi, Shu
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p. 6491 - 6493
(2007/10/03)
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- Synthesis and characterization of 4- and 4,4′-phosphorylated 2,2′-bis(diphenylphosphanyl)-1,1′-binaphthyls
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A convenient reaction sequence has been established to obtain selectively the mono- or bisphosphorylated BINAP derivatives 6-9. The structure of the new compounds was confirmed by NMR spectroscopy. The sodium salts of the phosphonic acid derivatives 8 and
- Kant, Michael,Bischoff, Stefan,Siefken, Rolf,Gruendemann, Egon,Koeckritz, Angela
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p. 477 - 481
(2007/10/03)
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- Preparation of enantiomerically pure 2′-substituted 2-diphenylphosphino-1,1′-binaphthyls by reductive cleavage of the carbon-phosphorus bond in a borane complex of 2-diphenylphosphino-2′-diphenylphosphinyl-1,1′-binaphthyl
-
Reaction of (S)-2′-boranatodiphenylphosphino-2-diphenylphosphinyl-1,1′- binaphthyl (3, borane complex of BINAP monoxide) with an excess of n-butyllithium in THF at -78°C brought about a selective cleavage of the carbon-phosphorus bond between the binaphthyl and diphenylphosphinyl groups to generate the binaphthyllithium 14, the treatment of which with electrophiles MeOD, I2, and ClSnMe3 gave, after removal of the borane, the corresponding 2′-substituted 2-diphenylphosphino-1,1′-binaphthyls (E-MOP 9: E = D, I, SnMe3), without loss of the enantiomeric purity.
- Shimada,Kurushima,Cho,Hayashi
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p. 8854 - 8858
(2007/10/03)
-
- Copolymerization of ethylene and carbon monoxide by phosphinite-modified palladium catalysts
-
Novel palladium complexes with bidentate phosphinite and mixed phosphine - phosphinite ligands of the general formula [(P^P)Pd(Me)Cl] were prepared. After halide abstraction, these complexes are highly active catalysts for the copolymerization of ethylene
- Keim,Maas
-
p. 271 - 276
(2007/10/03)
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- Practical Synthesis of (R)- or (S)-2,2'-Bis(diarylphosphino)-1,1'-binaphthyls (BINAPs)
-
Practical methods for the synthesis of (R)- or (S)-2,2'bis(diarylphosphino)-1,1'-binaphthyls (BINAPs), useful ligands for transition-metal-catalyzed asymmetric reactions, have been developed. (+/-)-2,2'-Bis(diphenylphosphinyl)1,1'-binaphthyl , prepared from 2,2'-dibromo-1,1'-binaphthyl and diphenylphosphinyl chloride, can be resolved into optical antipodes by the use of camphorsulfonic acid or 2,3-di-O-benzoyltartaric acid.Reduction of resolved BINAPO with trichlorosilane in the presence of triethylamine affords optically pure 2,2'-bis(diphenylphosphino)-1,1'-binaphthyl (BINAP).In a similar manner, several BINAP analogues have been prepared in optically pure form.The present procedures are suitable for obtaining these axially dissymmetric diphosphines in a large scale.The molecular structure of the 1:1:1 complex of (S)-(-)-BINAPO, (1R)-(-)-camphorsulfonic acid, and acetic acid has been studied by single-crystal X-ray analysis.
- Takaya, Hidemasa,Mashima, Kazushi,Koyano, Kinko
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p. 629 - 635
(2007/10/02)
-
- Preparation and lithiation of optically active 2,2'-dihalo-1,1'-binaphthyls. A general strategy for obtaining chiral, bidentate ligands for use in asymmetric synthesis
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Chiral, bidentate ligands based on the 1,1'-binaphthyl system have achieved remarkable success in certain asymmetric syntheses that have been reported in the literature. Enantiomeric excesses are often above 90% and may approach 99% or better. In the present paper, it is demonstrated that 2,2'-dibromo-1,1'-binaphthyl and the corresponding diodide can be obtained in preparative quantities with optical purities in excess of 98%. The compounds can be mono- or dilithiated, and the lithio intermediates are configurationally stable from -131°C up to at least -44°C. Yields of the dilithio intermediate are 95% or higher, and the monolithio intermediates can be formed in chemical yields of 80-85%. The discovery provides an efficient, general route for obtaining symmetrical and unsymmetrical chiral, bidentate ligands based on the binaphthyl system. These derivatives are expected to have broad applications in mechanistic studies of asymmetric reactions and in practical synthetic procedures. For example, (R)- and (S)-BINAP (2,2'-bis(diphenylphosphino)-1,1'-binaphthyl), which are reported to give enantiomeric excesses approaching 100% in certain rhodium-catalyzed hydrogenations, have been synthesized from 2-naphthol in overall yields ranging from 16% to 34%.
- Brown,Berry,Waterman,et al.
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p. 4717 - 4723
(2007/10/02)
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