Binaphthyl Backbone Research Articles

Atropochiral C,X‐ and C,C‐Chelating Carbon Ligands

AbstractIn the realm of atropochiral ligands initiated by the BINOL and BINAP paradigms and extended by modifications of the 1,1′‐binaphthyl backbone and the coordinating heteroatoms (O, P, N, S,..), the emerging domain of the carbon versions serving as spectator ligands in catalysis is reviewed. These atropochiral C,X‐chelating ligands are classified according to their coordinating mode (monodentate or bidentate), to the nature of the auxiliary donor X (a heteroatom or a carbon atom), to the overall charge of the coordinating carbon function (neutral or anionic C‐ligands), and to the hapticity of the coordinating carbon function (η1 for NHCs and ylides, or η2 for alkenes). Emphasis is put on both synthetic aspects and applications in catalysis, and especially in asymmetric catalysis. This survey suggests that the “carbon ligands” should continue to provide surprises not only in coordination chemistry and in stereoselective synthesis and catalysis, but also in fundamental molecular chemistry by pushing farther the stability limits of the metal–ligand interactions, thus reconciliating further the fields of organic and inorganic chemistry.

Graphical Abstract: Eur. J. Inorg. Chem. 16/2010

AbstractThe cover picture shows the molecular structure of an atropochiral C,X‐chelating ligand with the 1,1′‐binaphthyl backbone of BINAP and P,X‐chelating X‐MOP analogues. The primal role of the carbon element in the determination of chemical chirality is symbolized in the background by the diamond crystal mirror and in the forefront by a universal asymmetric carbon atom. The weights symbolize the added value of the natural or eutomeric configuration of such atoms in molecules of biological interest, which can be controlled by atropochiral ligands in enantioselective transition‐metal‐catalyzed processes. Details are presented in the Microreview by Y. Canac and R. Chauvin on p. 2325 ff.

Atropochiral C,X‐ and C,C‐Chelating Carbon Ligands (Eur. J. Inorg. Chem. 16/2010)

AbstractThe cover picture shows the molecular structure of an atropochiral C,X‐chelating ligand with the 1,1′‐binaphthyl backbone of BINAP and P,X‐chelating X‐MOP analogues. The primal role of the carbon element in the determination of chemical chirality is symbolized in the background by the diamond crystal mirror and in the forefront by a universal asymmetric carbon atom. The weights symbolize the added value of the natural or eutomeric configuration of such atoms in molecules of biological interest, which can be controlled by atropochiral ligands in enantioselective transition‐metal‐catalyzed processes. Details are presented in the Microreview by Y. Canac and R. Chauvin on p. 2325 ff.

Synthetic Access to a Novel Binaphthyl Ligand Bearing a Phosphine and a Triazole Donor Site

The combination of a diphenylphospinyl and a triazol-3-yl unit was realized for the first time at a 1,1'-binaphthyl backbone. This novel type of P,N-ligand is accessible as an enantiomerically pure compound in just a few steps. First experiments on the coordination chemistry with palladium(II) chloride have been carried out. A series of intermediates and a binuclear palladium(II) complex could be characterized by X-ray crystal structure analysis

A Series of Novel N,N‐Donor Ligands with Binaphthyl Backbones

AbstractChiral ligands with the 1,1′‐binaphthyl unit as the backbone play an important role in enantioselective catalysis. In this paper we present the synthesis and characterization of three novel azole‐functionalized 1,1‐binaphthyl derivatives. These systems are accessible from commercially available starting materials in not more than four steps. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)

Development of a New Chiral Spiro Oxazolinylpyridine Ligand (Spymox) for Asymmetric Catalysis

A novel optically active 2-(oxazolinyl)pyridine ligand (Spymox)having a spiro binaphthyl backbone was synthesized from an α,α-disubstituted α-aminoacid (H-Bin-OH), and successfully used in palladium-catalyzed asymmetricallylic alkylations to afford the corresponding alkylated productswith 99% ee.

A Chiral Bis-Sulfoxide Ligand in Late-Transition Metal Catalysis; Rhodium-Catalyzed Asymmetric Addition of Arylboronic Acids to Electron-Deficient Olefins

A bis-sulfoxide with a binaphthyl backbone is introduced as a readily available, chiral ligand entity in late-transition metal catalysis. Ligand p-tol-BINASO [where p-tol-BINASO is 1,1‘-binaphthalene-2,2‘-diyl-bis-(p-tolylsulfoxide)] is obtained in pure form in one single synthetic step from relatively cheap, commercially available starting materials. Precatalyst [{(P,R,R)-p-tol-BINASO}RhCl]2 was synthesized in high yield and structurally characterized by X-ray diffraction, and structural data were compared to the free ligand. The precatalyst shows both excellent reactivity and selectivity in the asymmetric 1,4-addition of arylboronic acids to cyclic α,β-unsaturated ketones and esters.

Chiral Phosphoric Acid Catalyzed Enantioselective Aza‐Friedel—Crafts Reaction of Indoles.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.

Chiral Phosphoric Acid‐Catalyzed Enantioselective Aza‐Friedel–Crafts Reaction of Indoles

AbstractA highly enantioselective 1,2‐aza‐Friedel–Crafts reaction of N‐tert‐butyldimethylsilylindole with N‐tert‐butoxycarbonyl aromatic imines is demonstrated using a BINOL‐derived monophosphoric acid catalyst. The present approach provides efficient access to 3‐indolylmethaneamines with aryl substituents in excellent enantioselectivities (up to 98 % ee). An inversion in the sense of enantioselection was found between monophosphoric acid catalysts bearing different substituents introduced at the 3,3′‐position of binaphthyl backbone. We also calculated the three‐dimensional structure of the monophosphoric acid catalysts to speculate on the inversion of the stereochemical outcome.

5,5′-Diamino-2,2′-bipyridin-1,1′-diium bis(5,5′-diamino-2,2′-bipyridin-1-ium) tetrakis(rac-1,1′-binaphthalene-2,2′-diyl phosphate) hexahydrate: a two-dimensional supramolecular hydrogen-bonded network

In the title compound, C10H12N42+·2C10H11N4+·4C20H12O4P−·6H2O, the 1,1′-binaphthalene-2,2′-diyl phosphate anion and 5,5′-diamino-2,2′-bipyridine as hydrogen-acceptor and -donor building blocks, respectively, are combined in a supra­molecular two-dimensional hydrogen-bonding network of one centrosymmetric diprotonated diamino­bipyridin-1,1′-ium dication, two monoprotonated diamino­bipyridinium cations, four phosphate counter-anions and six water mol­ecules of crystallization. Protonation of diamino­bipyridine to the bipyridinium mono- or dication enhances the hydrogen bonding due to the primary electrostatic attraction with the anion. The packing can be rationalized by a separation of the hydro­phobic binaphthyl backbone from the hydro­philic (RO)2PO2− phosphate groups, bipyridinium cation and water components. The binaphthyl tail-to-tail packing in the hydro­phobic lamellae as well as the diamino­bipyridinium packing is governed by π–π and C—H⋯π inter­actions.

Bisprolinediamides with the Binaphthyl Backbone as Organocatalysts for the Direct Asymmetric Aldol Reaction.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.

Bisprolinediamides with the Binaphthyl Backbone as Organocatalysts for the Direct Asymmetric Aldol Reaction

A series of L-prolineamides derived from various aromatic diamines including l,l'-binaphthyl-2,2'-diamine, were prepared in good yields. They were evaluated as catalysts for the direct asymmetric aldol reaction. The presence of the binaphthyl and proline moieties in one molecule has beneficial effects on the stereochemical outcome of the reaction of acetone with a model aldehyde. Furthermore, it was shown that dioxane as the solvent significantly improved both yield and enantioselectivity, reaching 89% and 86%, respectively.

Bisoxazoline ligands with an axial-unfixed biaryl backbone: the effects of the biaryl backbone and the substituent at oxazoline ring on Cu-catalyzed asymmetric cyclopropanation

The synthesis of novel C 2-symmetric bisoxazoline ligands with an axial-unfixed biaryl backbone and different substituents at the oxazoline ring is reported. The diastereomer equilibrium of these ligands in solution and their complexation behavior with the copper(I) ion were studied. Their application in Cu-catalyzed cyclopropanation of styrene, with diazoacetate, was carried out and the effects of the biaryl backbone and the substituent on the oxazoline ring in the catalysis were examined. The best result was obtained with the ligand having a 1,1′-binaphthyl backbone and a t-butyl group on the oxazoline ring, which afforded 89% de and 96% de for the trans- and cis-products of the above asymmetric cyclopropanation reaction, respectively.

Axially Chiral Guanidine as Enantioselective Base Catalyst for 1,4-Addition Reaction of 1,3-Dicarbonyl Compounds with Conjugated Nitroalkenes

A new strategy for designing chiral guanidine molecules is presented, which features the introduction of an axially chiral binaphthyl backbone. The axially chiral guanidine catalysts thus developed facilitated the highly enantioselective 1,4-addition reaction of 1,3-dicarbonyl compounds with a broad range of conjugated nitroalkenes and showed extremely high catalytic activity.

Rhodium, palladium and platinum coordination complexes of fluoroalkylated-BINAP and -MonoPhos ligands

The influence of perfluoroalkyl chains on the coordination chemistry of monodentate and bidentate binaphthyl-based ligands, MonoPhos and BINAP, has been evaluated, and a single-crystal X-ray structural determination of [Cp*RhCl 2(( R)-MonoPhos)] obtained. In spite of its size, the binaphthyl backbone is not sufficient to completely insulate the phosphorus donor atoms from the electronic effects of the perfluoroalkyl groups, and additional spacer units are required.

Design of an Axially Chiral Amino Acid with a Binaphthyl Backbone as an Organocatalyst for a Direct Asymmetric Aldol Reaction.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Design of an Axially Chiral Amino Acid with a Binaphthyl Backbone as an Organocatalyst for a Direct Asymmetric Aldol Reaction

Design of an Axially Chiral Amino Acid with a Binaphthyl Backbone as an Organocatalyst for a Direct Asymmetric Aldol Reaction

Design of an Axially Chiral Amino Acid with a Binaphthyl Backbone as an Organocatalyst for a Direct Asymmetric Aldol Reaction

Die robuste Binaphthyl-basierte Aminosäure (S)-1 ist als Katalysator einer direkten asymmetrischen Aldolreaktion zwischen Aldehyden und Aceton (siehe Schema) stabiler und selektiver als Prolin. Olefinische, heteroaromatische und aromatische Aldehyde erwiesen sich als geeignete Substrate; die entsprechenden Aldoladdukte wurden in guten Ausbeuten und ausgezeichneten Enantioselektivitäten erhalten.

(R)‐1,1′‐Binaphthyl‐2‐bis(pentafluorophenyl)borane Lewis Acids.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Synthesis, structure and catalytic properties of Re(I)–NOBIN Schiff base complex

The chiral mononuclear complex of Re(I)–NOBIN Schiff base (NOBIN = 1-amino-1′-hydroxylbinaphthyl) was synthesized via the reaction of Re(CO) 5Cl and corresponding tridentate ligand in methanol. The structure analysis reveals that the central metal coordinates with nitrogen atom of imine and oxygen atom of salicylaldehyde form a six-membered ring, while the left uncoordinated phenol group adjacent to the binaphthyl backbone forms a hydrogen bonding with water molecule coordinated with the Re(I) ion. This mononuclear complex shows some catalytic ability in asymmetric epoxidation and aziridination with moderate results.