BINOLs 2,2 -dihydroxy binaphthyl

In this reaction, 2,2 -dihydroxy binaphthyl derivatives (BINOLs) are used together with Ti(OP-i)4 complex. The highly polarized C=0 of the formyl group having a 5+ at the carbon atom is attacked by the most electron-abundant para position of N,N-dimethylanilines from a less sterically hindered direction (re) to give the product with an (R)-configuration 29. 

Reduction of Prochiral Ketones. BINOL has been used as the chiral ligand of the reagent BINAL-H (see Lithium Aluminum Hydride-2,2 -Dihydroxy-1,1 -binaphthyl, Vol. B) for asymmetric reduction. The reagent reduces prochiral unsaturated ketones to the corresponding secondary alcohols in up to 90% yield and >90% ee (eq 7) (f )-BINAL-H leads to the (i )-alcohols while (S)-BINAL-H gives the (S)-alcohols. 

Metal phenoxides are utilized extensively in organic synthesis as reagents, since they can readily be prepared from phenols and appropriate metal reagents, and the phenol moiety can easily be modified either sterically or electronically. Particularly, 2,2 -dihydroxy-l,l -binaphthyl (BINOL), salicylideneamine and Af,Af -ethylenebis(salicylideneamine) (salen) proved to be excellent phenol ligands for asymmetric synthesis. Since some of their reactions have recently been reviewed , it may not be appropriate to reproduce all of them. Instead, this section concentrates on the effect of the phenol moiety on the chemical reactivity and selectivity, and tries to provide structure-activity relationships for the metal phenoxide reagents. Metalated derivatives of monophenols, biphenols and salicylaldehyde imines are discussed separately. 

The enantiomers of VANOL (l,l -dihydroxy-3,3 -diphenyl-2,2 -binaphthyl) or its phenanthrene analogue VAPOL (l,l -dihydroxy-3,3 -diphenyl-2,2 -biphenanthryl) have been tested as BINOL substitutes in various nontransition metal catalyzed organic reactions (69,70). 

Lin and coworkers reported the chiral MOF [Cd3Cl6(pybinol)3] where pybinol is the pyridine-decorated chiral binol ligand (/ )-6,6 -dichloro-2,2 -dihydroxy-1,1 -binaphthyl-4,4 -bipyridine shown in Chart 3. The... 

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