A modular approach to neutral P,N-ligands: synthesis and coordination chemistry

• Vladislav Vasilenko,
• Torsten Roth,
• Clemens K. Blasius,
• Sebastian N. Intorp,
• Hubert Wadepohl and
• Lutz H. Gade

Beilstein J. Org. Chem. 2016, 12, 846–853, doi:10.3762/bjoc.12.83

• aromatic formamidines (1a–c) starting from triethyl orthoformate and aromatic amines. Low-temperature lithiation of 1 and addition to achiral (R = Ph) and axially chiral (R2 = BINOL) chlorophosphines R2PCl gave ligands 2 and 3 in excellent yields (Scheme 1) [11]. If the correct stoichiometry is maintained

• -fluorophenyl; R = phenyl or BINOL. Yields: [2a-Rh(cod)]BF4 = 85%, [2b-Rh(cod)]BF4 = 75%, [2c-Rh(cod)]BF4 = 88%, [3a-Rh(cod)]BF4 = 74%, [3b-Rh(cod)]BF4 = 90%, [3c-Rh(cod)]BF4 = 81%, [2a-Ir(cod)]BF4 = 77%, [2b-Ir(cod)]BF4 = 80%, [2c-Ir(cod)]BF4 = 88%, [3a-Ir(cod)]BF4 = 65%, [3b-Ir(cod)]BF4 = 81%, [3c-Ir(cod)]BF4

Cupreines and cupreidines: an established class of bifunctional cinchona organocatalysts

• Laura A. Bryant,
• Rossana Fanelli and
• Alexander J. A. Cobb

Beilstein J. Org. Chem. 2016, 12, 429–443, doi:10.3762/bjoc.12.46

• developed an aza-MBH process using β-ICPD in the reaction between N-sulfonyl-1-aza-1,3-butadienes and activated alkenes (Scheme 4) [25]. In this report, optimal selectivity required (R)-BINOL as a co-catalyst (see inset for proposed catalytic transition state – (R)-BINOL shown in red). Furthermore, the

• the flexible cinchona framework, which has a knock-on effect on the catalytic outcome. Interestingly, the chiral nature of the binol phosphoric acid catalyst (S)-49 in the anti-selective process was not thought to be hugely influential upon the stereochemical outcome. Indeed replacing it with diphenyl

• processes catalyzed by β-ICPD, as demonstrated by Shi and Li and co-workers. (b) Takizawa and co-workers demonstrated similar chemistry, but also utilized the catalyst α-ICPN (inset). (a) Chen’s asymmetric MBH reaction. Good selectivity was dependent upon the presence of (R)-BINOL (shown in red) as well as

Self and directed assembly: people and molecules

• Tony D. James

Beilstein J. Org. Chem. 2016, 12, 391–405, doi:10.3762/bjoc.12.42

• important it is to read and keep up to date with the literature. Taking that one step further, it is also very important to keep abreast of papers that cite your own work. This is clearly illustrated using a paper by Todd A. Houston, who discovered that the racemic form of our chiral binol boronic acid 8

• formed very strongly complexes with tartaric acid [60]. This paper made us realise that our chiral binol boronic acid 8 should be able to discriminate the enantiomers of tartaric acid and also bind strongly with other sugar acids. Therefore, with Jianzhang Zhao an outstanding Postdoctoral Research Fellow

• enantiomers of tartaric acid and also bound bind strongly with other sugar acids [61] (Figure 9). While, we were very happy with these results, we realised that the system could be improved by changing the fluorophore from binol, to a much better fluorophore such as anthracene. Therefore, we combined the

Recent advances in copper-catalyzed asymmetric coupling reactions

• Fengtao Zhou and
• Qian Cai

Beilstein J. Org. Chem. 2015, 11, 2600–2615, doi:10.3762/bjoc.11.280

• advantage of a chiral (R)-BINOL-bridge to link the two aromatic acids and obtained the coupling product with excellent stereocontrol (up to 100% de) (Scheme 1) [16][17][18][19]. In 1998, Martin et al. [20] applied this strategy to the asymmetric intramolecular biaryl coupling of sugar derivatives carrying 2

• )butanoates with CuI/BINOL-derived ligands in 2013, affording the chiral coupling products and recovered starting material with high enantioselectivity (Scheme 21). Recently, the aforementioned kinetic resolution strategy was applied to another type of substrates [51], leading to the formation of cyano

Synthesis of bi- and bis-1,2,3-triazoles by copper-catalyzed Huisgen cycloaddition: A family of valuable products by click chemistry

• Zhan-Jiang Zheng,
• Ding Wang,
• Zheng Xu and
• Li-Wen Xu

Beilstein J. Org. Chem. 2015, 11, 2557–2576, doi:10.3762/bjoc.11.276

• 5,5’-bitriazoles from acetylenic amide. The amine-functionalized polysiloxane-mediated divergent synthesis of trizaoles and bitriazoles. The cyclic BINOL-based 5,5’-bitriazoles. The one-pot click–click reactions for the synthesis of bistriazoles. The synthesis of bis(indolyl)methane-derivatized 1,2,3

Selected synthetic strategies to cyclophanes

• Sambasivarao Kotha,
• Mukesh E. Shirbhate and
• Gopalkrushna T. Waghule

Beilstein J. Org. Chem. 2015, 11, 1274–1331, doi:10.3762/bjoc.11.142

• 308 in the presence of CuSO4 and sodium ascorbate in acetonitrile/water to deliver the desired cyclophane derivative 309 (56%, Scheme 53). Similarly, a novel BINOL-based cyclophane 310 has been synthesized via click chemistry by incorporating two triazole moieties in the macrocycle [187]. Li and co

Diastereoselective and enantioselective conjugate addition reactions utilizing α,β-unsaturated amides and lactams

• Katherine M. Byrd

Beilstein J. Org. Chem. 2015, 11, 530–562, doi:10.3762/bjoc.11.60

• many ligands, magnesium–BINOL complex was identified as suitable catalyst for the 1,4-cyanation of 107. The authors obtained the 1,4-cyano products in both moderate to high yields and enantioselectivities for a variety of β-aryl substituted N-acylpyrazoles (Scheme 26). In 2007, Shibasaki and co-workers

• reported the asymmetric 1,4-addition of dibenzyl malonate to α,β-unsaturated N-acylpyrroles catalyzed by a La(OiPr)3–linked BINOL complex [220]. Optimal yields and enantioselectivies were realized by adding 1,1,1,3,3,3-hexafluoroisopropanol (HIFP) to the reaction mixture and by placing steric bulk near the

Chemistry of polyhalogenated nitrobutadienes, 14: Efficient synthesis of functionalized (Z)-2-allylidenethiazolidin-4-ones

• Viktor A. Zapol’skii,
• Jan C. Namyslo,
• Mimoza Gjikaj and
• Dieter E. Kaufmann

Beilstein J. Org. Chem. 2014, 10, 1638–1644, doi:10.3762/bjoc.10.170

• Supporting Information File 1). For comparison, the well-known atropisomer 1,1’-binaphthalene-2,2’-diol (BINOL) shows a rotational barrier of 158 kJ/mol with calculated data in good accordance with the experimental value [46]. In addition to substantial NMR, IR, and mass spectral characterization of the

Homochiral BINOL-based macrocycles with π-electron-rich, electron-withdrawing or extended spacing units as receptors for C₆₀

• Marco Caricato,
• Silvia Díez González,
• Idoia Arandia Ariño and
• Dario Pasini

Beilstein J. Org. Chem. 2014, 10, 1308–1316, doi:10.3762/bjoc.10.132

• several homochiral macrocycles has been achieved by using π-electron-rich, electron-deficient or extended aromatic dicarboxylic acids in combination with an axially-chiral dibenzylic alcohol, derived from enantiomerically-pure BINOL. Two series of cyclic adducts with average molecular D2 and D3 molecular

• cyclic adducts exhibit recognition properties towards C60 in toluene solutions (up to log Ka = 3.2) with variable stoichiometries and variable intensities of the charge-tranfer band upon complexation. Keywords: BINOL; C60; carbon nanomaterials; carbon nanostructures; chirality; macrocycles; sensors

• protocol for the preparation of several chiral macrocycles incorporating BINOL (1,1′-bi-2-naphthol) units, through the formation of bridging ester functionalities, which ensure chemical inertness for the purposes of supramolecular sensing, recognition, or self-assembly. We have shown their application in

Self-assembly of metallosupramolecular rhombi from chiral concave 9,9’-spirobifluorene-derived bis(pyridine) ligands

• Rainer Hovorka,
• Sophie Hytteballe,
• Torsten Piehler,
• Georg Meyer-Eppler,
• Filip Topić,
• Kari Rissanen,
• Marianne Engeser and
• Arne Lützen

Beilstein J. Org. Chem. 2014, 10, 432–441, doi:10.3762/bjoc.10.40

• far we have studied templates based on the Tröger’s base [27] and the 2,2’-dihydroxybinaphthyl (BINOL) [28] scaffold and identified the bend angle of these V-shaped compounds to be a critical factor for the degree of self-sorting that can be achieved [9][15][16][17][18][25][26][27][28]. The 9,9

New hydrogen-bonding organocatalysts: Chiral cyclophosphazanes and phosphorus amides as catalysts for asymmetric Michael additions

• Helge Klare,
• Jörg M. Neudörfl and
• Bernd Goldfuss

Beilstein J. Org. Chem. 2014, 10, 224–236, doi:10.3762/bjoc.10.18

• Helge Klare Jorg M. Neudorfl Bernd Goldfuss Department of Chemistry, Universität zu Köln, Greinstrasse 4, D-50939 Köln, Germany, Fax: +49(0)221-470-5057 10.3762/bjoc.10.18 Abstract Ten novel hydrogen-bonding catalysts based on open-chain PV-amides of BINOL and chinchona alkaloids as well as three

• ; Chakravarty et al. [24] tested an ansa-bridged BINOL-based PV-cyclodiphosphazane in the asymmetric reduction of acetophenone with BH3 (5–8% ee), while Gade et al. [25] recently introduced BINOL-based PIII-cyclodiphosphazane ligands to transition-metal catalysis (up to 84% ee). We anticipated that by

• in activating a hydrogen-bond-acceptor than commonly employed (thio)ureas. Synthesis of chiral open-chain PV-amides We evaluated both BINOL and chinchona alkaloids as chiral backbones. BINOL is a well-established chiral motif [30], while chinchona alkaloids are sterically very demanding, can be

A combined continuous microflow photochemistry and asymmetric organocatalysis approach for the enantioselective synthesis of tetrahydroquinolines

• Erli Sugiono and
• Magnus Rueping

Beilstein J. Org. Chem. 2013, 9, 2457–2462, doi:10.3762/bjoc.9.284

• the synthesis of tetrahydroquinolines from readily available 2-aminochalcones using a combination of photochemistry and asymmetric Brønsted acid catalysis. The photocylization and subsequent reduction was performed with catalytic amount of chiral BINOL derived phosphoric acid diester and Hantzsch

• optically active tetrahydroquinolines. Readily available substituted 2-aminochalcones were envisioned to undergo photocyclization to the corresponding quinolines which in the presence of a chiral BINOL-derived phosphoric acid diester and Hantzsch dihydropyridine as hydride donor [32][33][34][35][36][37

An overview of the synthetic routes to the best selling drugs containing 6-membered heterocycles

• Marcus Baumann and
• Ian R. Baxendale

Beilstein J. Org. Chem. 2013, 9, 2265–2319, doi:10.3762/bjoc.9.265

• protocol for resolving the racemate on large scale using (S)-BINOL was reported [88]. This method works via the co-crystal formation between (S)-BINOL and cis-(−)-lamivudine forming a binary complex which was characterised by single crystal X-ray crystallography. Raltegravir (3.18, Isentress), is another

Gold(I)-catalyzed enantioselective cycloaddition reactions

• Fernando López and
• José L. Mascareñas

Beilstein J. Org. Chem. 2013, 9, 2250–2264, doi:10.3762/bjoc.9.264

• substituents at the Binol ortho-positions (Au11, Scheme 9) [60]. Independently, Toste and co-workers reported that the related phosphoramidite–gold complex Au12, and the chiral gold catalyst Au13, derived from a C3-symmetric phosphite [66], were also able to induce excellent enantioselectivities in these [4

• active cyclobutanes [77]. Several chiral phosphoramidite–gold complexes, such as (S,R,R)-Au7, (S,R,R)-Au15 and (R,R,R)-Au16, derived from Siphos, Binol and Vanol, respectively, provided excellent enantioselectivities, displaying useful complementarity in some of the cases. Importantly, the method also

• Ph3PAuCl/AgNTf2 [79][80]. Moreover, for the latter cycloaddition with nitrones, the authors reported a enantioselective variant by using chiral phosphoramidite–gold complexes. In these cases, the binol-derived complexes, with aryl substituents at the 3 and 3’ positions, turned out to be the optimal systems

Synthesis of axially chiral gold complexes and their applications in asymmetric catalyses

• Yin-wei Sun,
• Qin Xu and
• Min Shi

Beilstein J. Org. Chem. 2013, 9, 2224–2232, doi:10.3762/bjoc.9.261

• Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 354 Fenglin Road, Shanghai 200032, People’s Republic of China 10.3762/bjoc.9.261 Abstract Several novel chiral N-heterocyclic carbene and phosphine ligands were prepared from (S)-BINOL. Moreover, their ligated Au complexes

• . The synthesis of compound 9 was reported by Slaughter and co-workers (Scheme 1) [49]. The usage of (S)-BINOL as the starting material to react with trifluoromethanesulfonic anhydride in the presence of DIPEA afforded at 0 °C in dichloromethane the corresponding product (S)-2'-hydroxy-1,1'-binaphthyl-2

• indicated that no reaction occurred in the absence of a Au catalyst (Table 1, entry 14). Conclusion Axially chiral Au(I) complexes exhibiting a binaphthalene scaffold with NHC or phosphine gold complexes on one side and an arene moiety on another side were prepared starting from axially chiral BINOL. A weak

Organocatalytic asymmetric selenofunctionalization of tryptamine for the synthesis of hexahydropyrrolo[2,3-b]indole derivatives

• Qiang Wei,
• Ya-Yi Wang,
• Yu-Liu Du and
• Liu-Zhu Gong

Beilstein J. Org. Chem. 2013, 9, 1559–1564, doi:10.3762/bjoc.9.177

• ]. These leading findings indicate that either Lewis base or Brønsted acid shows catalytic activity for the selenofunctionalization reaction. Since chiral phosphoric acids have been shown to be Brønsted acid/Lewis base bifunctional organocatalysts [29][30][31][32][33], we ask whether the chiral BINOL-based

Asymmetric Brønsted acid-catalyzed aza-Diels–Alder reaction of cyclic C-acylimines with cyclopentadiene

• Magnus Rueping and
• Sadiya Raja

Beilstein J. Org. Chem. 2012, 8, 1819–1824, doi:10.3762/bjoc.8.208

• optically active aza-tetracycles in good yields with high diastereo- and enantioselectivities under mild reaction conditions. Keywords: BINOL phosphate; [4 + 2] cycloaddition; Diels–Alder reaction; organocatalysis; Introduction The enantioselective aza-Diels–Alder reaction is an important method for the

• with cyclopentadiene providing optically active nitrogen-containing heterocycles (Scheme 1). Results and Discussion Our initial study began with the examination of the the aza-Diels–Alder reaction of cyclic C-acylimine 1 with cyclopentadiene (2) in the presence of BINOL-derived phosphoric acid diesters

• -Diels–Alder reaction. From the different catalysts tested, phosphoric acid diester 4b, with the 2,4,6-triisopropylphenyl substituent in the 3,3’-position of the BINOL backbone, proved to be the best catalyst, and the product was obtained with an encouraging enantiomeric excess of 74% (Table 1, entry 3

Asymmetric organocatalytic decarboxylative Mannich reaction using β-keto acids: A new protocol for the synthesis of chiral β-amino ketones

• Chunhui Jiang,
• Fangrui Zhong and
• Yixin Lu

Beilstein J. Org. Chem. 2012, 8, 1279–1283, doi:10.3762/bjoc.8.144

• ketones. Application of aryl methyl ketones in the asymmetric Mannich reaction by enamine catalysis remains elusive. On the other hand, the only chiral Brønsted acid catalytic system based on BINOL-phosphates was reported by Rueping et al. Unfortunately, the yields of the reported reactions were

Organocatalytic asymmetric allylic amination of Morita–Baylis–Hillman carbonates of isatins

• Hang Zhang,
• Shan-Jun Zhang,
• Qing-Qing Zhou,
• Lin Dong and
• Ying-Chun Chen

Beilstein J. Org. Chem. 2012, 8, 1241–1245, doi:10.3762/bjoc.8.139

• catalysis by amine 1h, although a longer reaction time was required to give a better yield (Table 1, entry 19). It should be noted that the reaction became sluggish when (S)-BINOL [32] was added, and even no reaction happened in the presence of other additives such as LiClO4 or Ti(OiPr)4 [33]. With the

Synthesis and anion recognition properties of shape-persistent binaphthyl-containing chiral macrocyclic amides

• Marco Caricato,
• Nerea Jordana Leza,
• Claudia Gargiulli,
• Giuseppe Gattuso,
• Daniele Dondi and
• Dario Pasini

Beilstein J. Org. Chem. 2012, 8, 967–976, doi:10.3762/bjoc.8.109

• chiral binol scaffolds, which incorporate either methoxy or acetoxy functionalities in the 2,2' positions and carboxylic functionalities in the external 3,3' positions, were used as the source of chirality. Two of these binaphthyls are joined through amidation reactions using rigid diaryl amines of

• complexation. Several macrocyclic systems capable of effective anion recognition and discrimination have been previously reported [16][17][18]. Binol (1,1'-binaphthyl-2,2'-diol) based synthons are popular in the recent literature; given their robustness, they are frequently used to impart or transfer chiral

• information, not only in the field of asymmetric synthesis and catalysis, but also in materials science [19][20][21][22][23][24]. During the course of our ongoing efforts dealing with the use of binol-based synthons for the production of functional, oriented nanomaterials and chiroptical sensors [25][26][27

Facile isomerization of silyl enol ethers catalyzed by triflic imide and its application to one-pot isomerization–(2 + 2) cycloaddition

• Kazato Inanaga,
• Yu Ogawa,
• Yuuki Nagamoto,
• Akihiro Daigaku,
• Hidetoshi Tokuyama,
• Yoshiji Takemoto and
• Kiyosei Takasu

Beilstein J. Org. Chem. 2012, 8, 658–661, doi:10.3762/bjoc.8.73

• triethylammonium chloride promotes the isomerization to give thermodynamically favourable ones in moderate yield [5]. However, harsh conditions (reaction temperature: ca. 100 to 200 °C) were required for the complete equilibration. Yamamoto and co-workers reported that a SnCl4–(BINOL monomethyl ether) complex (5

Development of the titanium–TADDOLate-catalyzed asymmetric fluorination of β-ketoesters

• Lukas Hintermann,
• Mauro Perseghini and
• Antonio Togni

Beilstein J. Org. Chem. 2011, 7, 1421–1435, doi:10.3762/bjoc.7.166

• . To start with, the (R)-BINOL-derived complex displayed low activity and selectivity (Table 6, entry 1). The phenyl-TADDOL ligand T1 induced enantiomeric excesses that increased with the steric requirements of the substrate ester group (Table 6, entry 2). The effect was more pronounced for 1-naphthyl

Directed ortho,ortho'-dimetalation of hydrobenzoin: Rapid access to hydrobenzoin derivatives useful for asymmetric synthesis

• Inhee Cho,
• Labros Meimetis,
• Lee Belding,
• Michael J. Katz,
• Travis Dudding and
• Robert Britton

Beilstein J. Org. Chem. 2011, 7, 1315–1322, doi:10.3762/bjoc.7.154

• The discovery of new chiral ligands and auxiliaries continues to expand the frontiers of catalytic asymmetric synthesis. In particular, C2-symmetric diols, such as (S)-BINOL (1) [1] and (−)-TADDOL (2) [2] (Figure 1), have garnered considerable attention owing to the wide variety of asymmetric

Synthesis of chiral mono(N-heterocyclic carbene) palladium and gold complexes with a 1,1'-biphenyl scaffold and their applications in catalysis

• Lian-jun Liu,
• Feijun Wang,
• Wenfeng Wang,
• Mei-xin Zhao and
• Min Shi

Beilstein J. Org. Chem. 2011, 7, 555–564, doi:10.3762/bjoc.7.64

• catalysts in chiral induction reactions [19][20][21][22][23][24][25]. The axially chiral biaryl framework, widely used in the design of chiral ligands such as BINAP [26][27], BINOL [28][29], and boxax [30], has proved to be very rigid, and was introduced in the development of NHC ligands by the Hoveyda

Synthesis of 5-(2-methoxy-1-naphthyl)- and 5-[2-(methoxymethyl)-1-naphthyl]-11H-benzo[b]fluorene as 2,2'-disubstituted 1,1'-binaphthyls via benzannulated enyne–allenes

• Yu-Hsuan Wang,
• Joshua F. Bailey,
• Jeffrey L. Petersen and
• Kung K. Wang

Beilstein J. Org. Chem. 2011, 7, 496–502, doi:10.3762/bjoc.7.58

• '-diol (BINOL) and BINOL derivatives as reagents in asymmetric synthesis has stimulated the development of new synthetic methods for 2,2'-disubstituted 1,1'-binaphthyls [8][9][10][11][12][13][14][15][16]. However, the great majority of the reported methods involved coupling of two properly substituted 1

• spectrometer, the signals of the methylene hydrogens on the five-membered ring could be discerned as an AB system at δ 4.27 (J = 21 Hz) and 4.25 (J = 21 Hz). The rotational barrier of BINOL as a member of the 2,2'-disubstituted 1,1'-binaphthyls was determined to be 37.2 kcal/mol at 195 °C in naphthalene

• , corresponding to a half-life of 4.5 hours for racemization [28]. The high stability of the configuration even at such an elevated temperature allows BINOL to be used in a variety of synthetic applications. The configurational stability of 20b and 20c, which could be regarded as 2,2'-disubstituted 1,1