Binaphthol condensation

Fulgides Modified on the Acid Anhydride Moiety. Dicyanomethylene-Condensed Fulgides Fulgenates and Fulgenolides (R)-Binaphthol-Condensed Fulgides Fulgides with Thioanhydride Moiety. 86-2... 

Inada, X, Uchida, S., and Yokoyama, Y, Perfect on/ofF switching oF emission oF fluorescence by photochromic reaction oF a binaphthol-condensed Fulgide derivative, Chem. Lett., 321, 1997. Chem. Lett., 961,1997. 

Functionalization in the 3-position has been accomplished by a Mannich type condensation as shown in Eq. (3.53). The process is initiated by heating binaphthol with N-( -butoxymethyl)morpholine for five days at 150° °. Under these conditions, a mix-... 

Thus, (1 A S Hra/7.v-chrysanthemic acid was condensed with 1,1 -binaphthol derivative using the TsCb/V-methylimidazole reagent to give the corresponding two sets of diastereomers (26) and (27). From the solution, only the (l/ )-trans-chrysanthemic acid ester (26) crystallized from the diastereomer mixtures. The ester was readily... 

The incorporation of two nonidentical chiral residues, each supporting C2 symmetry, into a mactocyclic poly ether affords a chiral crown compound with C2 symmetry provided its structure is constitutionally symmetrical. Thus, base-promoted reaction of the half-crown diol prepared from (5)-birraphthol with the half-crown ditosylate d-72 synthesized tom diacetone-manrritol affords (144) the 20-crown-6 derivative (S)-d-113 with C2 symmetry. When d-72 is condensed in like fashion with (/ 5)-binaphthol, then the diastereoisomeric 20-crown-6 derivative (/ )-d-114 can be separated chromatogiaphically tom (S)-d-113. In this matmer, (/ 5)-binaphthol is resolved by the carbohydrate unit during the synthesis. 

Methyl 2-methoxy-5,6-dihydro-2H-pyran-6-carboxylate (2 R = Me) can be obtained in optically active form by condensation of diene 1 with methyl glyoxylate in the presence of dichlorotitanium (R)-binaphthol catalyst (3) [45]. 

Scheme 118 shows enantioselective condensation of alkanals and ni-tromethane promoted by a binaphthol-modified rare earth alkoxide in wet THF. Reaction of the initially formed metal /3-nitro alkoxide and acidic nitromethane, leading to the j8-nitro alcohol product and chiral metal nitronate, makes the C—C bond formation catalytic (284). 

The ligands in 9.7-9.9 are all based on N,0 or N,N donor-atom-based chelating systems. In contrast, the ligands in 9.10-9.12 are all bidentate alkoxides, with 0,0 donor atoms. The chirality in binapthol, 9.11, arises from the fact that due to steric interactions the molecule does not have a plane of symmetry. The two naphthyl rings lie in different planes. The complex 9.12 has binaphthol as the ligand. Complexes such as 9.12 are used as catalysts in nitroaldol condensation reaction (see Section 9.5.4). 

Asymmetric nitroaldol condensation, reaction 9.10, has been used to make an intermediate for the drug S-propanolol 9.61. The condensation reaction is catalyzed by the chiral heterobimetallic binaphthol complex 9.12 with high (>90%) enantioselectivity. 

Trilluoroacetaldehyde (fluoral) undergoes facile highly stereoselective condensation with silyl enol ethers under titanium(ll) chloride binaphthol catalysis to give 2. ... 

Preparative Methods racemic BNPPA is obtained by condensation of ( )-binaphthol (see (R)-l,l -Bi-2,2 -naphthol) and Phosphorus Oxychloride followed by hydrolysis (eq 1). Racemic BNPPA can be resolved by recrystallization of its cinchonine salt. ... 

These reactions can also be made enantioselective (in which case only one of the four isomers predominates) ° ° by using chiral enol derivatives, chiral aldehydes or ketones, or both. ° " Chiral bases can be used, such as prohne, ° prohne derivatives, or chiral additives, used in conjunction with the base. ° A chiral binaphthol dianion has been used to catalyze the reaction. Chiral auxiharies ° ° have been developed that can be used in conjunction with the aldol condensation, as well as chiral catalysts and chiral ligands " ... 

Chiral boronales are generated m situ by reaction of binaphthols 3.7 (R = H, Ph) [231] with BH3 in the presence of acetic acid [778], with H BBr [781] or with B(OPh)3 [782, 783], Chiral borates are formed by reactions of substituted (S)-prolinol derivative 2.13 (R =- CPl OH) and BBr3 [784], These boronates and borates are valuable catalysts in asymmetric Diels-Alder reactions [73, 231, 601, 780], Tartaric acid derivatives, such as borate 3.8 and acyloxyboranes 3.9 recommended by Yamamoto and coworkers [73,601,778,780,785-791], are very efficient catalysts in asymmetric Diels-Alder reactions and in condensations of aldehydes with allylsilanes, enoxysilanes or ketene acetals. These catalysts are generated in situ from substituted monobenzoates of (RJl)- or (S -tartaric acid and BH3 (R = H) or an arylboric acid (R = Ar). The best asymmetric inductions are observed with catalysts 3.9, R = /-Pr. 1,3,2-OxazaboroMnes 3.10, prepared from a-aminoacids [44, 601, 780, 792, 793], are efficient catalysts in asymmetric Diels-Alder reactions. The catalyst generated from A -tosyltrytophan 3.11 is more efficient than borolidines 3.10 (R = Et, /-Pr). The catalysts 3.10 prepared from 3.11, 3.12 and 3.13 are also useful in asymmetric condensations of aldehydes with ketene acetals [794-797]. 

A chiral boron reagent, derived from equimolar amounts of (R)-or (5)-binaphthol and triphenyl borate, promotes the condensation of chiral imines with t-butyl acetate silyl ketene acetal in high diastereomeric excess (eq 12). ... 

Spiro compounds. For example, Gong and coworkers combined 17 and in situ generated azomethine ylides derived from the condensation of aminomalonate 33 and aldehydes 15 to afford spiro[pyrrolidin-3,3 -oxindoles] 34 in good yields and excellent stereoselectivities when the binaphthol phosphoric acid derivative IV was used as catalyst (Scheme 10.8) [16]. 

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