1,1’ -binaphthalene-2,2’ -diol chirality

Axially chiral guanidines with an external guanidine unit such as dinaphthoazepineamidine are effective catalysts for the enantioselective addition of p-oxoesters and a 1,3-diketone to di-ferf-butyl azodicarboxylates to yield cx-hydrazino-p-oxoesters and a-hydrazino-p-dike-tones in 54-99% yields and in 15-98% ee [44]. For example, stirring 2-oxocyclopenta-necarboxylate and di(tert-butyl) azodicarboxylate in THF in the presence of 0.05 mol% catalyst for four hours at —60° C provides an adduct in quantitative yield and in 97% ee (Scheme 4.15). The (R)-catalyst was prepared from (/ )-2,2 -dimethyl-3,3 -binaphthalene-diol ditriflate, 4-methoxyphenylboronic acid and 3.5-di(rert-butyl)phenylboronic acid in six steps. 

Various chiral crown ethers based on [1,1 -binaphthalene]-2.2 -diol, lactose or other chiral 1,2-di-ols were tested as catalyst in the addition of methyl benzcneacetate to methyl 2-propenoate using sodium amide or potassium tert-butoxide as the base. Some pertinent examples are given261 262 396. 

A chiral zirconium catalyst generated from Zr(0,-Bu)4 and (R)-3,3 -diiodo-1,1 -binaphthalene-2,2 -diol [(f )-3,3/-l2BINOL] catalyzed... 

The applicability of axially chiral 1, l -binaphthalcnc-8,8 -diol in asymmetric Diels-Al-der reactions was studied by Fuji and colleagues190. They studied the Lewis acid catalyzed reaction of the unsymmetrically substituted maleate ester of 1,1 -binaphthalene-8,8 diol 302 with cyclopentadiene. The diastereoselectivity proved to depend strongly on the Lewis... 

A diol that has proved to be an ideal bridge is the rigid chiral [l,l -binaphthalene]-2,2 -diol which is commercially available in high optical purity in both enantiomers. Furthermore, this diol can be synthesized easily in enantiomerically pure form by phenolic oxidation25, followed by a resolution of the racemic mixture25 21. In addition, a part of this valuable chiral auxiliary can be recycled after the coupling reaction. 

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. 

A kinetic resolution with respect to the racemic diene 66 could be achieved in the Diels-Alder reaction promoted by a chiral Lewis acid prepared from BHj in the presence of (S)-3,3 -diphenyl-l,r-binaphthalene-2,2 -diol and juglone (47) in the synthesis of (+)-emycin A and (+)-ochromycinone (35) [66] (compare previous investigations by Kelly [67]). 

Enantlomerically pure 1,1 -binaphthalene-2,2 -diols are used in various types of asy 6ti 1c syntheses, for example, as chiral auxiliaries in a method for the asyn i 6tflc reduction of ketones. ... 

Miscellaneous.- A simple method to resolve racemic l,l -binaphthalene-2,2 -diol involves reaction with menthyl phosphorodichloridite (139) and separation of the diastereomeric phosphites by crystallisation from ether. The new cyclic chlorodiaminophosphine (140), prepared in and two new cyclic triaminophosphines (141) have been used to determine the enantiomeric purity of chiral alcohols, thiols, and amines by means of Ip n.m.r. New optically pure phosphites used for Rh catalysed asymmetric hydroformylation reactions are (142), two diastereomers of (143), and (144) the diphosphinite (145) was similarly employed. Some new cyclic aminophosphines (146) were prepared for use as ligands in asymmetric Pd catalysed allylic substitution reactions. 

To be accurate, the definition should be restricted to asymmetric reactions catalyzed by a combination of l,r-binaphthalene-2,2 -diol (BINOL, 4) and Ti(0 -Pr)4. Nonetheless, this chapter will give some background on non-chiral Lewis acid promoters, and include other asymmetric catalytic systems. We will not discuss the allylations that are promoted by Lewis bases, which are reviewed elsewhere, nor cover the reactions with other electrophiles. Excellent reviews already exist on "Selective Reactions Using Allylic MetaM and Catalytic Enantioselective Addition of Allylic Organometallic Reagents to Aldehydes and Ketones , as well as in the comprehensive monograph "Modern Carbonyl Chemistry. The use of BINOL-based catalysts in other fields of organic synthesis has also been reviewed. ... 

Nevertheless, A 12 proved to be superior in terms of yield and selectivity. The linker between the two sulfonamide moieties was extensively varied. A pentyl chain showed hereby the best outcome. Making use of the chiral l,l -binaphthyl-2,2 -diol (or l,l -binaphthalene-2,2 -diol or l,l -bi-2-naphthol) (BINOL) backbone, Benaglia designed catalyst A 14, which showed excellent yields (98%) and good enantioselectivities (81%). 

A completely different type of reagent was proposed in 1996 by Japanese workers for the stereochemical assignment of carboxylic acids this is 1,1 -binaphthalene-8,8 diol (BNDO see Figure 151a), which presents axial chirality and is available in the two enantiomeric forms. 

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