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

Molecular recognition of organic ammonium ions in solution using synthetic receptors

• Andreas Späth and
• Burkhard König

Beilstein J. Org. Chem. 2010, 6, No. 32, doi:10.3762/bjoc.6.32

Recent progress on the total synthesis of acetogenins from Annonaceae

• Nianguang Li,
• Zhihao Shi,
• Yuping Tang,
• Jianwei Chen and
• Xiang Li

Beilstein J. Org. Chem. 2008, 4, No. 48, doi:10.3762/bjoc.4.48

Control of asymmetric biaryl conformations with terpenol moieties: Syntheses, structures and energetics of new enantiopure C₂-symmetric diols

• Y. Alpagut,
• B. Goldfuss and
• J.-M. Neudörfl

Beilstein J. Org. Chem. 2008, 4, No. 25, doi:10.3762/bjoc.4.25

• structure of (P)-BICOL, Erel. = 0.0 kcal/mol. B3LYP/6-31++G**:AM1 optimized structure of (M)-BIMEOL, Erel. = 5.4 kcal/mol. B3LYP/6-31++G**:AM1 optimized structure of (P)-BIMEOL, Erel. = 0.0 kcal/mol. Atropisomeric BINOL and conformationally restricted, (−)-fenchone-based (M)-BIFOL. Syntheses of (M)-BIMOL

Asymmetric aza-Diels- Alder reaction of Danishefsky's diene with imines in a chiral reaction medium

• Bruce Pégot,
• Olivier Nguyen Van Buu,
• Didier Gori and
• Giang Vo-Thanh

Beilstein J. Org. Chem. 2006, 2, No. 18, doi:10.1186/1860-5397-2-18

• Jørgensen,[13][14] and the chiral copper complexes of phosphino sulfenyl ferrocenes reported by Carretero.[15] The catalyst systems also include the Lewis acid catalysts based on boron-BINOL complexes [16][17][18] and lastly zinc-BINOL complexes developed by Whiting et al.[19] In all the above cases

A superior P-H phosphonite: Asymmetric allylic substitutions with fenchol- based palladium catalysts

• Bernd Goldfuss,
• Thomas Löschmann,
• Tina Kop-Weiershausen,
• Jörg Neudörfl and
• Frank Rominger

Beilstein J. Org. Chem. 2006, 2, No. 7, doi:10.1186/1860-5397-2-7

• computational transition structure analyses, these phenyl and anisyl phosphinites are not "monodentate" but form chelate complexes via π-coordination. Biphenyl-2,2'-bisfenchol (BIFOL)[13] was developed as combination of a flexible biaryl axis (as in BINOL) and sterically crowded hydroxy groups (as in TADDOLs

An exceptional P-H phosphonite: Biphenyl- 2,2'-bisfenchylchlorophosphite and derived ligands (BIFOPs) in enantioselective copper- catalyzed 1,4-additions

• T. Kop-Weiershausen,
• J. Lex,
• J.-M. Neudörfl and
• B. Goldfuss

Beilstein J. Org. Chem. 2005, 1, No. 6, doi:10.1186/1860-5397-1-6

• = fenchyl-aryl dihedral angle between C1'-C2'-C3'-O2). Monodentate phosphorus ligands, e.g. BINOL-based phosphoramidites or TADDOL-based phosphites, are highly efficient in copper catalyzed enantioselective conjugate additions. Modular phosphoramidites (R= NR'2) or phosphites (R= OR') from reactive

Mixtures of monodentate P-ligands as a means to control the diastereoselectivity in Rh-catalyzed hydrogenation of chiral alkenes

• Manfred T. Reetz and
• Hongchao Guo

Beilstein J. Org. Chem. 2005, 1, No. 3, doi:10.1186/1860-5397-1-3

• involves the use of additives, catalyst poisons or catalyst activators.[10][11] Based on the discovery that monodentate BINOL-derived phosphites,[12][13] phosphonites[14][15] and phosphoramidites [16][17][18] are excellent ligands in enantioselective Rh-catalyzed olefin-hydrogenation, we proposed in 2003 a

• (Scheme 1). If the hetero-combination dominates due to enhanced activity and enantioselectivity, a superior catalytic profile can be expected. A mechanistic study of Rh-catalyzed olefin-hydrogenation using BINOL-derived monodentate phosphites (homo-combination) has shown that two such ligands are bound to

• the metal in the transition state of the reaction,[13] and it is certain that in the case of mixtures analogous species are involved.[19][20] This new strategy was first employed in Rh-catalyzed olefin-hydrogenation using mixtures of BINOL-derived phosphites and phosphonites[19][20] and was then