Binaphthyl, 2,2 -dihydroxy

Racemic Crystal-to-Conglomerate Crystal Transformation Reactions in 2,2 -Dihydroxy-1,1 -binaphthyl-l /le4N+CI Complex... 

Recently, catalytic asymmetric Diels-Alder reactions have been investigated. Yamamoto reported a Bronsted-acid-assistcd chiral (BLA) Lewis acid, prepared from (R)-3-(2-hydroxy-3-phcnylphenyl)-2,2 -dihydroxy-1,1 -binaphthyl and 3,5A(trifluoromethy I) - be nzeneboronic acid, that is effective in catalyzing the enantioselective Diels-Alder reaction between a,(3-enals and various dienes.62 The interesting aspect is the role of water, THF, and MS 4A in the preparation of the catalyst (Eq. 12.19). To prevent the trimerization of the boronic acid during the preparation of the catalyst, the chiral triol and the boronic acid were mixed under aqueous conditions and then dried. Using the catalyst prepared in this manner, a 99% ee was obtained in the Diels-Alder reaction... 

Note This procedure has been scaled up to provide 50 g of the optically pure 7,7 -diallyloxy-2,2 -dihydroxy-1,1 -binaphthyl. 

Asymmetric cyclization of nerol and famesol.1 A biomimetic cyclization of nerol to limonene can be effected with an aluminum reagent 2 and a chiral leaving group. Thus the neryl ether 3 of R-( + )-2,2 -dihydroxy-1,1 -binaphthyl is cyclized... 

Potassium triethylborohydride, 260 Sodium borohydride, 21 Ring-forming reactions 2,2 -Dihydroxy-1,1 -binaphthyl, 113 Other asymmetric reactions Camphor-10-sulfonic acid, 62 Di-jjL-chlorobis(l,5-cyclooctadiene)di-rhodium-2,3-0-Isopropylidene-2,3-dihydroxy-1,4-bis(diphenyl-phosphine)butane, 153... 

Among the preparative methods used for obtaining P-chiral phosphorus compounds, there are procedures involving the use of optically pure auxiliaries like (—)-menthol [40], (—)-ephedrin [41,42], or more recently, the kinetic resolution of 1-hydroxymethylalkylphenylphosphine oxides using Pseudomonas or Candida antarctica lipases [43], It has been found that some [(alkyl-substituted)arene] phosphinates and phosphine oxides can also be resolved efficiently by inclusion complexation with optically active 2,2 -dihydroxy-1, 1 -binaphthyl (17) [44],... 

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.. 

Dihydroxy-1,1 -binaphthyl and Crystallographic Study of Two Diastereomeric Complexes with (CH3)(C6H5)(OCH3)PO, J. Org. Chem., 53, 308-312. 

Tanaka, K., Okada, T., and Toda, F. (1993) Separation of the Enantiomers of 2,2 -Dihydroxy-1,1 -binaphthyl and 10,10 -Dihydroxy-9,9 -biphenanthryl by Complex- ation withN-Alkylcinchonidinium Halides, Angew. Chem. Int. Ed. Engl., 32, 1147-1148. 

Fujimoto, Y. Iwadated, H. Ikekawa, N. Preparation of optically active 2,2 - dihydroxy-1,1 -binaphthyl via microbial resolution of the corresponding racemic diester. J. Chem. Soc., Chem. Commun. 1985, 1333-1334. 

Asymmetric hydride reduction.1 The complex (2) prepared in situ from 1, LiAlH4, and ethanol (1 1 1 ratio) reduces alkyl aryl ketones to the corresponding (S)-alcohols in 85-98% ee. Optical yields are only moderate (20-35%) in reductions of aliphatic ketones. The complex is comparable to the related complex obtained using optically active 2,2 -dihydroxy-1,1 -binaphthyl (9, 169-170). 

ASYMMETRIC REDUCTION OF KETONES (S)-(—)-2-Amino-3-methyl-1,1 -diphenyl-butane- 1 -ol. (S)-4-Anilino-3-methylamino-1 -butanol. 2,2-Dihydroxy-1,1 -binaphthyl. 

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. 

In 1951 Bothner-By first attempted asymmetric reductions based on the conversion of lithium aluminum hydride (LAH) into a chiral alkoxy derivative by reaction with (+)-camphor. Since this pioneering work, the use of chirally modified LAH reagents has been the focus of much attention. In 1979, the first virtually complete enantiofacial recognition of prochiral carbonyl compounds was accomplished by using LAH modified with optically pure 2,2 -dihydroxy-1,1 -binaphthyl and a simple alcohol (BINAL-H). Asymmetric reduction with chiral 2,5-dimethylborolane also gave alcohols in high optical yields." Recently, excellent results have been obtained using a chirally modified sodium borohydride... 

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