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Privileged biaryl frameworks, BINOL and NOBIN, were efficiently constructed with sole 1-DNQs as arylation reagents under one set of reaction conditions. The judicious selection of palladium catalytic system plays a pivotal role in the excellent selectivities. This transformation accommodated fairly broad substrate generality for both 2-naphthol and N-Boc-2-naphthylamine and afforded the structurally diversified BINOLs and NOBIN derivatives in high efficiency. Notably, the bromo substituent which cannot be survived in conventional palladium catalyzed reactions were well-compatible with this set of conditions, providing an effective handle for further enriching the library of BINOLs and NOBINs. Preliminary attempts on the asymmetric variant of this reaction were also performed with up to 80:20 er for BINOLs synthesis.

We developed herein a regioselective construction of non-C2 symmetrical NOBIN-type biaryls through a cascade N-arylation and [3,3]-sigmatropic rearrangement from O-arylhydroxylamines and diaryliodonium salts under mild conditions. The employment of copper salt could inhibit the further O-arylation of the newly formed biaryl products, otherwise, O-arylated NOBIN-type products were furnished in moderate to good isolated yields. The products of this protocol can be further converted into highly valuable functional molecules and heterocycles.

Summary Functionalization of arenes represents the most efficient approach for constructing a core backbone of important aryl compounds. Compared with the well-developed electrophilic aromatic substitution and transition-metal-catalyzed C–H activation, nucleophilic aromatic substitution remains challenging because of the lack of a convenient route for rapid conversion of the σH adduct to other stable and versatile intermediates in situ. Guided by computational design, we were able to realize asymmetric nucleophilic aromatic substitution by introducing a nitroso group on naphthalene via chiral phosphoric acid catalysis. This strategy enables efficient construction of atropisomeric indole-naphthalenes and indole-anilines with excellent stereocontrol. Density functional theory (DFT) calculations provide further insights into the origins of enantioselectivity and the reaction mechanisms. The successful application in the synthesis of NOBINs (2-amino-2′-hydroxy-1,1′-binaphthyl) extends the utility of this strategy.

Herein, we disclosed a transition metal-free cascade protocol for the construction of 2-hydroxy-2′-amino-1,1′-biaryls that are difficult to prepare by employing conventional methods. The nucleophilic substitution of arylhydroxylamines to arylammonium salts at room temperature generates transient N,O-diarylhydroxylamines that could rapidly undergo a tandem process, including a [3,3]-sigmatropic rearrangement and rearomatization to afford NOBIN analogues.

C1-symmetric vanadyl Schiff-base complexes were synthesized by reacting vanadium(IV) acetylacetonate with (S)-3-[(1-(2-hydroxynaphthalen-1-yl)naphthalen-2-ylimino]methyl]-phenanthrene-4-ol and (S)-2-{[1-(2-hydroxynaphthalen-1-yl)naphthalen-2-ylimino]methyl}tetraphene-1-ol. The complexes were characterized by MALDI-TOF-MS, UV–vis, and circular dichroism (CD) spectroscopy. The catalysts showed moderate activity for the oxidation of thioanisole to methyphenylsulfoxide with hydrogen peroxide, tert-butyl hydroperoxide, and cumene hydroperoxide as the oxidants.

The importance of axial chirality in enantioselective synthesis has been widely recognized for decades. The practical access to certain structures such as biaryl amino phenols known as NOBINs in enantiopure form, however, still remains a challenge. In drug delivery, the incorporation of axially chiral molecules in systematic screening has also received a great deal of interest in recent years, which calls for innovation and practical synthesis of structurally different axially chiral entities. Herein we present an operationally simple catalytic N-alkylation of sulfonamides using commercially available chiral amine catalysts to deliver two important classes of axially chiral compounds: structurally diverse NOBIN analogs as well as axially chiral N-aryl sulfonamides in excellent enantiopurity. Structurally related chiral sulfonamide has shown great potential in drug molecules but enantioselective synthesis of them has never been accomplished before. The practical catalytic procedures of our methods also bode well for their wide application in enantioselective synthesis., NOBINs and other axially chiral entities have received a great deal of interest in recent years. Here, the authors report the kinetic resolution of racemic amino phenols and the enantioselective preparation of axially chiral N-aryl sulfonamides with excellent level of enantiopurity and broad substrate scope.

Atropisomerically enriched biaryl frameworks are ubiquitous in many fields of chemistry. Enantioselective aryl–aryl cross-coupling provides the most straightforward entry to atropisomeric biaryls, with remarkable application potential in the field of chemical science. However, their development is hindered due to the lack of convenient and pragmatic protocols. Here, we report a method for the asymmetric synthesis of a myriad of 2-amino-2′-hydroxy-1,1′-binaphthyl (NOBIN) and 1,1’-binaphthyl-2,2’-diamine (BINAM) derivatives in excellent yields and enantioselectivities via a redox-neutral cross-coupling protocol. Two complementary systems were devised employing a chiral phosphoric acid–salt complex or Ni(OTf)2/chiral bis(oxazoline) ligand catalytic system for accessing atropisomeric NOBIN and BINAM derivatives, respectively. This work provides an alternative avenue to enantioenriched biaryls, and provides the capability to explore the synthetic and catalytic potentials of NOBIN- and BINAM-based frameworks. Axially chiral biaryls have proven to have a wide variety of uses—perhaps most importantly as ligands in asymmetric catalysis—but their synthesis remains challenging. Here, Bin Tan and colleagues report a redox-neutral aryl–aryl coupling, providing a direct route to N,N and N,O axially chiral biaryls in high yields and enantioselectivities.

NOBIN and BINAM derivatives harboring biaryl frameworks are recognized as a class of important atropisomers with versatile applications. Here, we present an efficient synthetic route to access such compounds through copper-catalyzed domino arylation of N-arylhydroxylamines or N-arylhydrazines with diaryliodonium salts and [3,3]-sigmatropic rearrangement. This reaction features mild conditions, good substrate compatibility, and excellent efficiency. The practicality of this protocol was further extended by the synthesis of biaryl amino alcohols.

A versatile kinetic resolution of protecting-group-free BINAMs and NOBINs has been realized through chiral phosphoric acid catalyzed triazane formation with azodicarboxylates. A series of mono-N-protected and unprotected BINAMs, diphenyl diamines and NOBIN derivatives could be kinetically resolved with excellent performances (with s factor up to 420). The gram-scale reactions and facile derivatizations of the chiral products demonstrate the potential of these methods in the asymmetric synthesis of chiral catalysts and ligands.

Herein, we present a transition-metal free direct O-arylation of arylhydroxylamines employing diaryliodonium salts as arylation reagents to form transient N,O-diarylhydroxylamines that could subsequently undergo [3,3]-sigmatropic rearrangement and re-aromatization to afford structurally diverse NOBIN analogs in good to excellent yields under mild conditions.

Heterogeneous metal catalysts constitute a very important tool for the synthesis of functional materials and fine chemicals owing to their high efficiency, robustness, and facile recyclability. Biaryls are privileged structural motifs in many natural products, chiral ligands, and catalysts. The oxidative biaryl coupling reaction is one of the most promising methods for biaryl synthesis in terms of atom and step economies. However, although oxidative biaryl coupling of naphthols has been studied thoroughly, the coupling of aryl amines providing biaryl amines like 2,2'-diamino-1,1'-binaphthyl (BINAM) and 2-amino-2'-hydroxy-1,1'-binaphthyl (NOBIN) derivatives remains elusive. Recently, we have found that aryl amines are efficiently dimerized with the use of a heterogeneous Rh/C catalyst under acidic conditions. This heterogeneously catalyzed method can be adapted to the highly selective cross-coupling reaction of aryl amines and the intramolecular biaryl coupling reaction. Furthermore, we developed an aerobic direct C-H oxidation of polycyclic aromatics catalyzed by a recyclable heterogeneous rhodium catalyst. These methodologies are advantageous compared with the existing reactions owing to the mild aerobic conditions employed and the facile recyclability of the heterogeneous catalysts used.

A simple ternary ion-pair complexation protocol has been developed for rapid testing of the enantiopurity and the assignment of absolute configurations of various acid and ester derivatives employing 1,1′-[binaphthalene]-2,2′-diamine (BINAM) as a novel chiral solvating agent (CSA) in the presence of trifluoromethanesulfonic acid (TFMS) as a third component. TFMS effectively enhances the ability of complexation between BINAM and the chiral analyte by stabilizing the ternary complex through strong hydrogen bonding interactions. In addition to testing of the enantiopurity, the systematic variation in the chemical shift positions of the distinctly identifiable peaks of the diastereomer complexes generated by using enantiopure (R)-BINAM and (S)-BINAM permitted the unambiguous assignment of the stereospecific configurations of different acid and ester derivatives. The protocol is superior to our earlier report where NOBIN with TFMS permitted only the absolute configurational assignment of hydroxy acids. The application of the protocol for the determination of enantiomeric contents of an asymmetric reaction has also been demonstrated.

2′-Amino-1,1′-binaphthalen-2-ol (NOBIN) serves as a versatile chiral solvating agent (CSA) in the presence of trifluoromethanesulfonic acid (TFMS). The formation of a ternary complex has been established by NMR, UV–Vis, fluorescence and IR studies. The mechanism of interactions among the three components in the ternary complex has been proposed and the ternary complex structures of different diastereomers have been established by DFT based theoretical calculations. The present protocol has its ubiquity not only in the analysis of the enantiomeric composition of molecules possessing diverse functionalities, but also in determining the stereospecific assignment of hydroxy acids.

The utility of enantiopure BINOL (1,10-Bi-2-naphthol), in a ternary ion-pair complex, which is obtained using a carboxylic acid and an organic base, as a versatile chiral solvating agent (CSA) has been demonstrated for chiral analysis and the absolute configuration assignment of hydroxy acids. Another protocol where the utility of NOBIN as a CSA has been developed for discrimination and absolute configuration assignment of acids, hydroxy acids and their derivatives with a distinct strategy where a third ingredient, p -toluenesulfonic acid ( p -TsOH) serves as a linker. In addition some three component chiral derivatization protocols have been introduced, such as the use of 2-formylphenylboronic acid and enantiopure mandelic acid or a primary amine for the determination of the configuration of primary amines and hydroxy acids, respectively. A simple, rapid and highly efficient three component chiral derivatizing protocol has also been discussed which was developed for assigning the absolute configuration of chiral α-hydroxy acids and their derivatives, which involves the coupling of 2-formylphenylboronic acid with ( R )-[1,1-binaphthalene]-2,2-diamine, and ( S )-[1,1-binaphthalene]-2,2-diamine separately. In a few examples, the DFT based theoretical calculations have been carried out to determine the geometry optimized structures of the complexes.

This computational and experimental study represents a case where “push–pull π+/π–” (PPππ) systems have shown a concrete application in chemistry apart from spectral tuning. The most notable finding of this investigation was that a mode of interaction unprecedented in catalysis, a PPππ system, played a crucial role in the Henry reaction catalyzed by a NOBIN-based squaramide. The results show that the PPππ system stabilizes the most favorable pathway, P1, with 2.7–4.7 kcal/mol. This is vital for the differentiation in energy of P1 over the remaining pathways and directly affects both the reactivity and stereoselectivity of this reaction. These results suggest that PPππ systems are promising tools with great potential for catalysis., We thank the Government of Aragon DGA (Research Group E-104) for financial support of our research. J.V.A.-R. thanks the DGA for a predoctoral contract.

Herein we present a highly efficient N-heterocyclic-carbene (NHC)-catalyzed atroposelective acylation of amino bisphenols to provide access to a wide range of 1,1′-biaryl-2,2′-amino alcohols (NOBIN analogs) in high yield and with uniformly excellent enantioselectivity. This catalytic system is shown to proceed through a combination of desymmetrization and secondary kinetic resolution to produce the axially chiral products in excellent enantioselectivity.

Direct entry to optically pure 2-amino-2'-hydroxy-1,1'-binaphthyl (NOBIN) derivatives by an iron-catalyzed stereoselective oxidative cross-coupling reaction between 2-naphthol and 2-aminonaphthalene with a labile chiral auxiliary is reported. This efficient method offers entry to tailor-designed ( R a)- and ( S a)-NOBINs that are not accessible by any other means.

2'-Amino-1,1'-binaphthalene]-2-ol (NOBIN) fails to serve as a chiral solvating agent (CSA) for acids, hydroxy acids and their derivatives due to its negligibly weak or absence of weak molecular interactions with the chiral analyte. In the present study, we demonstrate the utility of NOBIN as a CSA for discrimination of acids, hydroxy acids and their derivatives with a distinct strategy wherein a third ingredient, p-toluenesulphonic acid (p-TsOH), was introduced as a linker, which induces hydrogen bonding interactions and thus permits the NMR spectroscopic differentiation. The formation of ternary complex is further established by UV-Vis, fluorescence, IR and PXRD studies. Ternion complex structures were optimized by the DFT calculations.

P∗-Monodentate diamidophosphite and diastereomeric P,N-containing phosphite ligands have been synthesized from enantiomerically pure N-Bn-NOBIN and used as asymmetric inductors in Pd-catalyzed allylic substitution and Cu-catalyzed conjugate addition reactions. The best results (up to 93% ee) were obtained for the Pd-catalyzed allylic alkylation of (E)-1,3-diphenylallyl acetate with 1-cyclohexenylpyrrolidine. The reactions of P,N-containing ligands with Pd(COD)Cl2 at molar ratios of L/M = 1 and 2 were studied using 1H, 13C, and 31P NMR spectroscopy as well as HRESI mass spectrometry, showing the trans-PdCl2L2 complex was the only product.

Reactions that let chemists selectively make one enantiomer of a molecule over another fall into a field of modern organic chemistry called asymmetric catalysis. These reactions are crucial for syn...

BINAP aminophosphines are prevalent N,P-bidentate, chiral ligands for asymmetric catalysis. While modification via the BINAP-nitrogen linkage is well explored and has provided a diverse body of derivatives, modification of the other substituents of the phosphorous center is another avenue in generating new congeners of this important class of chiral ligands. Herein reported are new BINAP aryl aminophosphines with electron rich or deficient substituents on the aryl rings. This scalable synthesis converted readily available starting material, (S)-BINOL, to a key intermediate (S)-NOBIN, from which the final chiral aminophosphines were prepared via a palladium-catalyzed, phosphonylation reaction. The aryl substituents are able to modify the electronic properties of the phosphorous center as indicated by the range of 31P-NMR shifts of these new ligands. A computational analysis was performed to linearly quantitate contributions to the 31P-NMR shifts from both resonance and field effects of the substituents. This correlation may be useful for designing and preparing other related aminophosphines with varying ligand properties.

International audience; This review collects the major progress in the field of enantioselective transformations promoted by chiral lanthanide catalysts, covering the literature since the beginning of 2012, well illustrating the power of these special catalysts to promote many types of reactions.

Phosphoramidite and P-stereogenic phosphorodiamidite ligands derived from (Sa)-2-phenylamino-2′-hydroxy-1,1′-binaphthyl (N-Ph-NOBIN) and bis(1-phenyl-ethyl)amine were synthesised, fully characterised, and the absolute configuration of the stereogenic phosphorus atoms was assigned. The phosphoramidite ligand L2 features three non-bridged substituents at phosphorus comprising the bis(1-phenylethyl)amine and two NOBIN moieties. The NOBIN units are bound to the phosphorus through the oxygen atoms with two pendant nitrogen atoms. In the Ni-catalysed hydrovinylation of styrene no conversion was observed with the phosphorodiamidites, while the phosphoramidite ligands led to active catalysts with a marked co-operative effect on selectivities. Whereas the racemic product was obtained with the (Sa,Sa,SC,SC) diastereomer, the (Sa,Sa,RC,RC) diastereomer proved to be one of the best ligands for this reaction, leading to almost perfect selectivity and ees of up to 91%.

An efficient single-step conversion of (R)-BINAM to highly enantiopure (R)-NOBIN is developed.

A series of new camphorsulfonylated ligands derived from chiral 2-amino-2′-hydroxy-1,1′-binaphthyl (NOBIN) and (+)-camphorsulfonic acid were synthesized by a short and simple synthetic sequence, and their enantioselective catalytic activities were assessed in the nucleophilic addition reaction of dialkylzinc reagents to aldehydes in the presence of titanium tetraisopropoxide. The most efficient ligand, N-hydroxycamphorsulfonylated (S)-NOBIN, gave (S)-addition products with good yields and up to 87% of ee value. The 1H nuclear magnetic resonance (NMR) and 13C NMR results of the titanium titration experiments on this ligand indicate that the most likely catalytic reactive species involved in this catalytic asymmetric addition is a bimetallic titanium complex. A possible catalytic reaction mechanism is proposed. Chirality 24:825–832, 2012. © 2012 Wiley Periodicals, Inc.

An investigation into the N-acylation of atropisomeric anilines 8 and 2, which are related to NOBIN (1), catalysed by small molecule chiral pyridine-based nucleophilic catalysts is described. The first organocatalytic kinetic resolution (KR) of an atropisomeric aniline is described.

Synthesis was carried out of the new mixed-ligand square-planar platinum(II)complexes {Pt(R2SO)[(-)-S-NOBIN]Cl2}, where (-)-S-NOBIN was S-2-amino-2′-hydroxy-1,1′-binaphthyl (R = Me, Et). The complexes are of interest as catalysts for asymmetrical synthesis. The detailed analysis of NMR, UV, and CD spectra of these compounds was performed. These complexes were established to be a mixture of the corresponding cis- and trans-isomers.

A series of aminophosphine ligands was synthesized from 2-amino-2′-hydroxy-1,1′-binaphthyl (NOBIN). Their asymmetric induction efficiency was examined for silver(I) catalyzed enantioselective allylation reaction of benzaldehyde with allyltributyltin. Under the optimized reaction conditions, quantitative yield as well as moderate ee value (54.5% ee) of product was achieved by the catalysis with silver(I)/3 complex. The effects of the binaphthyl backbone and the substitutes situated at chelating N, P atoms on enantioselectivity of the reaction were also discussed.

A new type of dendritic NOBIN derived Schiff base ligands has been synthesized and applied to titanium catalyzed hetero-Diels-Alder reaction of Danishelfsky's diene and aldehydes, affording the corresponding 2-substituted 2,3-dihydro-4H-pyran-4-one in good yields and moderate enantioselectivities (up to 59.2% ee). It was found that the size of dendron attached to the tri-dentated ligands has slight impact on the enantioselectivity of the reaction and the second generation of dendritic ligand exhibited the best enantioselectivity.

A series of hybrid phosphine-phosphoramidite ligands has been designed and synthesized in moderate yields from chiral BINOL (1,1'-bi-2-naphthol) or NOBIN (2-amino-2'-hydroxy-1,1'-binaphthyl). They have achieved highly regio- and enantioselectivities in Rh-catalyzed asymmetric hydroformylations of styrene derivatives (branched/linear ratio up to 56.6, ee up to 99 %), vinyl acetate derivatives (up to 98 % ee), and allyl cyanide (up to 96 % ee). Systematic variation of ligand structure showed that the steric factor on the phsophoramidite moiety determined the performance of the ligand. With the increased hindrance, the branched/linear ratio rose, while the ee value dropped in the hydroformylation of styrene. However, the N-substituents did not influence the selectivities much.

A preparative method of synthesis of optically pure S-2-amino-2′-hydroxy-1,1′-binaphthyl (S-Nobin), the precoursor in the synthesis of other asymmetric 1,1-binaphthyls applied as the ligands at the creation of the catalysts of asymmetric synthesis, is modified. The UV and CD spectra of this compound were studied in detail and essential dependence of spectral information on the solvent nature was shown.

This review is intended to update the most recent developments in asymmetric hetero-Diels–Alder (HDA) reactions of carbonyl compounds, covering the literature from 2000 to 2008. The reactions of unactivated aldehydes, activated aldehydes, activated ketones and the inverse HDA reactions of α,β-unsaturated ketones and α,β-unsaturated aldehydes are successively investigated. This review clearly demonstrates the power of asymmetric HDA reactions of carbonyl compounds for the construction of chiral six-membered oxygen-containing heterocycles, with extensive synthetic applications in natural or unnatural products with a wide range of biological activity. Figure options Download full-size image Download as PowerPoint slide

Two new amido binuclear complexes {( 1 )YN(SiMe 3 ) 2 } 2 · C 7 H 8 ( 3 · C 7 H 8 ) and {( 2 )SmN(SiMe 3 ) 2 } 2 · C 6 H 14 ( 4 · C 6 H 14 ) have been readily prepared in good yields by amine elimination reaction between Ln[N(SiMe 3 ) 2 ] 3 (Ln = Sm, Y) and chiral NNO ligands, ( S )-2-(pyridin-2-ylmethylamino)-2′-hydroxy-1,1′-binaphthyl ( 1 H 2 ) and ( S )-5,5′,6,6′,7,7′,8,8′-octahydro-2-(pyrrol-2-ylmethyleneamino)-2′-hydroxy-1,1′-binaphthyl ( 2 H 2 ), respectively. They both have been characterized by various spectroscopic techniques, elemental analyses, and X-ray diffraction analyses. They are active catalysts for asymmetric hydroamination/cyclization of aminoalkenes and ring-opening polymerization of rac -lactide, affording cyclic amines in excellent conversions with moderate ee values and isotactic-rich polylactides, respectively.

Novel chiral H′ 4 -NOBIN was synthesized in 66% yield through partial hydrogenation of 2-amino-2′-hydroxy-1,1′-binaphthyl, and the structure was proved via X-ray analysis of its salicyl-aldehyde Schiff base, which was tested in the enantioselective titanium-catalyzed hetero-Diels-Alder reaction of Danishefsky’s diene with aldehydes. The reaction provided dihydropyranone in moderate to high yield (up to 99%) and enantioselectivities (up to 84.5% ee).

A mild, operationally simple, and single-step transition-metal-free protocol for the synthesis of enantiomerically pure (R)-(+)-2'-amino-1,1'-binaphthalen-2-ol (R-NOBIN) from (R)-(+)-1,1'-binaphthyl-2,2'-diamine (R-BINAM) is reported. The one-pot conversion proceeds with good yield and shows no racemization. The hydroxyl on the R-NOBIN product was shown to have come from water in the reaction medium via an H2(18)O study. The correct value of the specific rotation of R-NOBIN was reported.

The goal of this review is to collect the major developments in enantioselective titanium-promoted 1,2-alkylation, 1,2-arylation, 1,2-alkynylation, 1,2-allylation and 1,2-vinylation reactions of carbonyl compounds reported since the beginning of 2008, well illustrating the power of these inexpensive, nontoxic and highly abundant catalysts to provide remarkably diverse chemical reactivity. Figure options Download full-size image Download as PowerPoint slide

2-Amino-2'-hydroxy-1,1'-binaphthyl (NOBIN, 3) can be considered as the analogue of 1,1'-bi-2naphthol (BINOL, 1) and 1,1'-bi-2-naphthylamine (BINAM, 2) in terms of its functionality and scaffold. Since the first report on the synthesis of NOBIN by Kocovsky, the chemistry of NOWN has been developed rapidly in the last decade. This article summarizes its synthesis, modification and application of its derivatives as the chiral ligands in asymmetric catalysis. The methods for the preparation of enantiopure NOBIN included asymmetric cross-coupling reaction of 2-naphthol and 2-naphthylamine, optical resolution of its racemic form and transformation from enantiopure BINOL. A variety of chiral ligands could be easily obtained by simple transformation from NOBIN. Their application in various asymmetric reactions, such as diethyl zinc addition to aldehydes, allylation of aldehydes, allylic substitutions, 1,4-addition to alpha,beta-unsaturated ketones, aldol-type reaction, Diels-Alder and hetero-Diels-Alder reactions, transfer hydrogenation of ketones, cyclopropanation, phase-transfer catalysis of alkylations, ring-opening/cross metathesis, alpha-vinylation/arylation of ketones and Suzuki coupling reactions, clearly demonstrated that NOBIN has become one type of privileged scaffold for construction of various chiral ligands for asymmetric catalysis.

A series of new phosphite–pyridine ligands, based on the H 8 -binaphthyl backbone, were synthesized and employed in the copper-catalyzed enantioselective 1,4-conjugate addition of diethylzinc to acyclic enones. Ligands derived from ( S )-H 8 -NOBIN provided better results than their parent ligands in the reaction. Ligand L1 provided excellent ees for trans -4-aryl-3-buten-2-ones (up to 97.8% ee) as substrates. Ligand L2 was very efficient for various para -chalcones, and up to 97.2% ee was achieved.