1,1 -Binaphthyl-2,2 -diol

Triflates of phenols are carbonylated to form aromatic esters by using PhjP[328]. The reaction is 500 times faster if dppp is used[329]. This reaction is a good preparative method for benzoates from phenols and naphthoates (473) from naphthols. Carbonylation of the bis-triflate of axially chiral 1,1 -binaphthyl-2,2 -diol (474) using dppp was claimed to give the monocarboxy-late 475(330]. However, the optically pure dicarboxylate 476 is obtained under similar conditions[331]. The use of 4.4 equiv. of a hindered amine (ethyldiisopropylamine) is crucial for the dicarbonylation. The use of more or less than 4.4 equiv. of the amine gives the monoester 475. 

Benzoin, methylbenzoin, ethylbenzoin, isopropylbenzoin, benzoin oxime, cyclobutyldianilide carbamate, 1,1 -binaphthyl-2,2 -diol, trans-stilbene oxide, and Trogers s base Polymethacrylate 104, 96... 

Mori, K., and Toda, F. (1990) Optical Resolution of Arsine Oxides by Complexation with Optically Active [1,1 -Binaphthyl]-2,2 -diol, Bull. Chem. Soc. Jpn., 63, 2127-2128. 

Diols such as the optically active 1,1 -binaphthyl-2-2 -diol (BINOL) have been used as versatile templates and chiral auxiliaries in catalysts employed successfully in asymmetric synthesis. The application of enzymes in the enantioselective access to axially dissymmetric compounds was first reported by Fujimoto and coworkers.83 In aqueous media, the asymmetric hydrolysis of the racemic binaphthyl dibutyrate (the ester) using whole cells from bacteria species afforded the (A)-diol with 96%ee and the unreacted substrate (A)-ester with 94% ee at 50 % conversion. Recently, in non-aqueous media, lipases from Pseudomonas cepacia and Ps. fluorescens have been employed in the enantioselective resolution and desymmetrization of racemic 6,6 -disubstituted BINOL derivatives using vinyl acetate.84 The monoacetate (K)-73 (product) was obtained in 32-44 % chemical yields and 78-96% ee depending on the derivatives used. The unreacted BINOL (S)-72 was obtained in 30-52 % chemical yield and 55-80% ee. 

The enantiomeric atropoisomers of 1,1 -binaphthyl-2,2 -diol (BINOL) and bis-diphenylphosphonate derivatives (BINAP) are completely synthetic molecules that have been developed to exploit the axial dissymmetry induced by the restricted rotation about the biaryl bond (Scheme 1.8) [64]. During the past 15 years, these compounds have become the most widely used ligands for both stoichiometric and catalytic asymmetric reactions, with many analogues and derivatives having been developed recently. 

Benzoin acetate, methylben-zoin, Troger s base, tra/w-stilbene oxide and 1,1 -binaphthyl-2,2 -diol Aminopropyl silica gel (LiChrospher 1000, 5 pm) coated with helically chiral poly(diphenyl-2-pyridylmethyl methacrylate) (PDPM) Methanolic solution of ammonium acetate (2.5 mM, pH 4.5) 300 mm x 100 pm i.d. 200 mm effective length, chiral separation 163... 

Oxidative cross-coupling of two electronically-different 2-naphthols with CuCl2 in the presence of tert-butylamine Preparation of 3-methoxy carbonyl-1,1 -binaphthyl-2,2 -diol (395) [58]... 

Keywords Aryl iodides, aliphatic amines, CuBr, racemic-1,1 -binaphthyl-2,2 -diol (rac-BINOL), K3PO4, N,N-Dimethyl formamide (DMF), room temperature, coupling reaction, amination, N-arylation of aliphatic amines... 

In 1994, Shibasaki et al. reported on the reaction between malonate and enone catalyzed by a lithium-free lanthanum-1,1 -binaphthyl-2,2 -diol (La-BINOL) complex. ... 

Clathrates of [tri-O-thymotide (TOT), brucine, sparteine, 2,2 -dihydroxy-1,1 -binaphthyl-diol] Alkanes, unbranched chiral hydrocarbons, acids and esters bearing small substituents, halogenated hydrocarbons, sulfoxides, phosphine oxides, phosphinates, piperidines [59-64]... 

In the case of binaphthyl ether 263, the secondary C—O bonds were hydrogenolyzed exclusively to provide the desired binaphthyl diol 264 (Scheme 81). ""... 

Meyers has also reported the use of chiral oxazolines in asymmetric copper-catalyzed Ullmann coupling reactions. For example, treatment of bromooxazoline 50 with activated copper powder in refluxing DMF afforded binaphthyl oxazoline 51 as a 93 7 mixture of atropisomers diastereomerically pure material was obtained in 57% yield after a single recrystallization. Reductive cleavage of the oxazoline groups as described above afforded diol 52 in 88% yield. This methodology has also been applied to the synthesis of biaryl derivatives. 

In 2004, Dieguez et al. reported the development of novel C2-symmetric dithioether ligands derived from the corresponding binaphthyl or biphenanthryl diols. Thus, various (i )-binaphthyl dithiols substituted by alkyl groups on the sulfur atom in order to increase the steric bulk were synthesised, and the corresponding mononuclear cationic Ir(I) -cyclooctadiene complexes were prepared and characterised (Scheme 8.20). NMR studies demonstrated that, in all cases, the coordination of the ligands proceeded with complete stereoselectivity at the... 

A number of optically active 1,1 -binaphthyl compounds, 8168 and 9,169 have been prepared with a view to use them as asymmetric catalysts. Compounds 8 (X = Br and OTf)170,171 and 9 [R3 = Me(OTf)2]169 have been used to resolve diols in their reaction with benzoyl chloride. Tin hydrides based on structure 8 (X2 = MeH,172 Bu H,173 and Me3CCH2H171) have been designed for carrying out enantioselective reductions. 

This biocatalytic method is therefore quite promising for the synthesis of complex molecules. Very recently, it was reported 1121] that HRP catalyzes the oxidation of 2-naphthols to l,l -binaphthyl-2,2 -diols with moderate enantiomeric excess (ee 38-64%) (Eq. 5). However, in view of the analytical techniques used, these data have to be questioned [167]. As shown recently, atrop-selective biaryl coupling can only be achieved by means of dirigent protein as chiral auxiliary [122]. 

In Ught of the recent developments in thiourea, diol, and phosphoric-acid-mediated catalysis, far fewer studies have focused on the use of chiral carboxyhc acids as suitable hydrogen bond donors. To this end, Mamoka synthesized binaphthyl-derived dicarboxylic acid 49 which catalyzes the asymmetric Mannich reaction of N-Boc aryl imines and tert-diazoacetate (Scheme 5.65) [120]. The authors postulate that catalytic achvity is enhanced by the presence of an addihonal car-boxyhc acid moiety given that use of 2-napthoic acid as catalyst provided only trace amounts of product... 

A related approach has recently been reported by Belokon and Kagan et al. These workers used chiral TADDOL-type diols, derived from tartaric acid and 2-amino-2 -hydroxy-1,1 -binaphthyl (NOBIN), as catalysts to obtain yields of up to 95% and enantioselectivity up to 93% ee [59-61], The catalytically active species seem to be the sodium salts of the diols. 

Data from the literature show that even if new convenient preparative methods are being developed for the resolution of l,l/-binaphthyl-2,2/-diol (17) via a phosphite using (—)-menthol as a resolving agent [39], the inclusion complexation method can still compete with these, owing to its simplicity, efficiency, and low cost. 

Dihydroxy-1,1 -binaphthyl and 1,6-Bis(o-chloropheny 1)-1,6-dipheny 1-hexa-2,4-diyne-l,6-diol, Chem. Lett., 509-512.. 

Kano has studied extensively the recognition of anions and zwitterions by both native and derivatized cyclodextrins [ 16]. The native (3-cyclodextrin com-plexation properties were examined with respect to binaphthyl derivatives. For both l,T-binaphthalene-2,2,-dicarboxylic acid and l,T-binaphthalene-2,2 -diol phosphate almost no chiral recognition was observed. The enantiomers of binaphthyl-2,2 -dicarboxylic acid were better distinguished using a per-O-methylated (3-cyclodextrin derivative in place of the native (3-cyclodextrin. 

Peroxidases are also active in the oxidation of naphthyl derivatives. In particular, when the substrates are 2-naphthols, the interesting derivatives 1,1 -dinaphthyl-2,2 -diols are formed [23] (Fig. 6.Id). In the presence of suitable substituents blocking the rotation of the naphthyl moieties, chiral binaphthyls can be obtained with enantiomeric enrichment [33, 34]. 

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