1,1 -Binaphthalene-2,2 -diol ethers

In an oven dried glass flask under an argon atmosphere at — 78 UC, 950 mg (5 mmol) of methyl 2,3-dihydro-1-oxo-l/f-indene-2-carboxylate in 10 mL of toluene are added to 2.2 mg (0.2 mmol) of potassium rert-butoxide in 5 mL of toluene. 356 mg (0.2 mmol) of (5, 6 )-bis[3,3 -dimethyl-l,l -binaphthalene]-2,2 -diol bis(diethy-lencoxy) ether [(5,.5)-3) are added, followed after 10 min by 700 mg (10 mmol) of 3-buten-2-one in 10 mL of toluene and the mixture is stirred for 120 h at — 78 °C after which it is poured into 35 mL of sat. aq NH4C1. The toluene layer combined with a toluene wash solution is dried over MgS04 and evaporated at 40 "C. The crude adduct is purified by chromatography over silica gel (C H2C12) yield 624 mg (48%) 99% ee. 

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. 

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. 

The air stable and storable zirconium catalyst, formed from Zr(0 Bu)4, 3,3 -diiodo-l,l -binaphthalene-2,2 -diol (3,3 -l2-BINOL), -propanol and water, with the putative dimeric structure (7.33) also catalyses auft -selective asymmetric aldol reactions. While this process is beheved to proceed through an acyclic transition state, as depicted in Figure 7.2, it is postulated that the greatest steric interaction is now between the silyl enol ether substituent R3 and the bulky Lewis acid resulting in the formation of the fluft -diastereomer predominantly. 

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