746-46-3Relevant articles and documents
Chiral Ligands in Hypervalent Iodine Compounds: Synthesis and Structures of Binaphthyl-Based λ3-Iodanes
Zhang, Huaiyuan,Cormanich, Rodrigo A.,Wirth, Thomas
, (2021/12/22)
Several novel binaphthyl-based chiral hypervalent iodine(III) reagents have been prepared and structurally analysed. Various asymmetric oxidative reactions were applied to evaluate the reactivities and stereoselectivities of those reagents. Moderate to excellent yields were observed; however, very low stereoselectivities were obtained. NMR experiments indicated that these reagents are very easily hydrolysed in either chloroform or DMSO solvents leading to the limited stereoselectivities. It is concluded that the use of chiral ligands is an unsuccessful way to prepare efficient stereoselective iodine(III) reagents.
Practical synthesis of axially chiral dicarboxylates via Pd-catalyzed external-CO-free carbonylation
Konishi, Hideyuki,Hoshino, Fumika,Manabe, Kei
, p. 1438 - 1441 (2016/10/09)
We have developed a safe and practical synthetic method for preparing axially chiral diphenyl dicarboxylates using Pd- catalyzed external-CO-free carbonylation with phenyl formate as a CO surrogate. Optimized conditions consisted of axially chiral [1,1′-binaphthalene]-2,2′-diyl ditriflate and its congeners, each easily prepared from commercially available enantiomerically pure diols, Pd(OAc)2, 1,3-bis(diphenylphosphino)-propane, ethyldiisopropylamine, and no solvent. To demonstrate the potential utility of these products, this method was conducted on gram-scale and the phenyl ester products were converted to other useful compounds, and both processes were carried out without difficulty.
Practical synthetic protocols of enantiopure 1,1′-binaphthyl-2, 2′-dicarboxylic acid and 2,2′-dicyano-1,1′-binaphthyl starting from optically active dibromide precursor
Hoshi, Takashi,Nozawa, Eiji,Katano, Masayoshi,Suzuki, Toshio,Hagiwara, Hisahiro
, p. 3485 - 3487 (2007/10/03)
Dilithiation of optically active 2,2′-dibromo-1,1 ′-binaphthyl 2 with t-BuLi followed by carboxylation of the resulting dilithio-intermediate 3 with CO2 gave optically active 1,1′-binaphthyl-2,2′-dicarboxylic acid 1, which was further transformed to its dicyano derivative 4. Both of these transformations were carried out in a one-pot operation and the products were obtained in excellent yields with no observable racemization.
A new synthetic route to enantiomerically pure axially chiral 2,2′-bipyridine N,N′-dioxides. Highly efficient catalysts for asymmetric allylation of aldehydes with allyl(trichloro)silanes
Shimada, Toyoshi,Kina, Asato,Hayashi, Tamio
, p. 6329 - 6337 (2007/10/03)
New axially chiral 2,2′-bipyridine N,N′-dioxides 1 were obtained in an enantiomerically pure form by way of cyclic diesters 6 or 7 which were formed by the esterification of diols 2 with (R)-2,2′-bis(chlorocarbonyl)-1,1′-binaphthalene (5). Epimerization of the kinetic products at the ester formation (Rnap,Spyr)-6 to the thermodynamically stable isomers (Rnap,Rpyr)-7 was observed in refluxing toluene or in the presence of trifluoroacetic acid. One of the N,N′-dioxides 1a which is substituted with phenyl groups at the 6 and 6′ positions was found to be highly catalytically active and enantioselective for the asymmetric allylation of aldehydes with allyl(trichloro)silane giving homoallyl alcohols.
A novel axially chiral 2,2′-bipyridine N,N′-dioxide. Its preparation and use for asymmetric allylation of aldehydes with allyl(trichloro)silane as a highly efficient catalyst
Shimada, Toyoshi,Kina, Asato,Ikeda, Syushiro,Hayashi, Tamio
, p. 2799 - 2801 (2007/10/03)
(Matrix presented) New axially chiral 2,2′-bipyridine N,N′-dioxides were obtained by a new method that does not involve any procedures for the separation of enantiomers. One of the dioxides, (R)-3,3′-bis(hydroxymethyl)-6,6′-diphenyl-2,2′-bipyridine N,N′-dioxide, exhibited extremely high catalytic activity for the asymmetric allylation of aldehydes with allyl(trichloro)silane. The allylation of aromatic aldehydes proceeded in the presence of 0.01 or 0.1 mol % of the dioxide catalyst to give the corresponding homoallyl alcohols of up to 98% ee.
A practical synthesis of C2-symmetric chiral binaphthyl ketone catalyst
Seki,Yamada,Kuroda,Imashiro,Shimizu
, p. 1677 - 1680 (2007/10/03)
A practical synthesis of 11-membered C2-symmetric binaphthyl ketone (R)-1, a catalyst for asymmetric epoxidation, was developed. (±)-1,1'-Binaphthyl-2,2'-dicarboxylic acid [(±)-6] was efficiently resolved by (R)-(-)-1-cyclohexylethylamine to give (R)-6 in >99% ee and in 38% yield. Condensation of the acid chloride derived from (R)-6 with 1,3-dihydroxyacetone dimer at 60-70 °C provided the desired chiral ketone (R)-1 in 61-63% yield without need for high dilution techniques.
Anomalous CD/UV exciton splitting of a binaphthyl derivative: The case of 2,2′-diiodo-1,1′-binaphthalene
Di Bari, Lorenzo,Pescitelli, Gennaro,Marchetti, Fabio,Salvadori, Piero
, p. 6395 - 6398 (2007/10/03)
The UV and CD spectra of (R)-(+)-2,2′-diiodo-1,1′-binaphthalene show an unexpectedly large value of the wavelength splitting between the two main bands, resulting from the exciton coupling of 1Bb transitions. An hypothesis is proposed on transition moments directions, making it possible to relate quantitatively the observed splitting to the orthogonal arrangement found in the solid state and calculated for the structure in solution.
Facile synthesis of enantiopure 1,1'-binaphthyl-2,2'-dicarboxylic acid via lipase-catalyzed kinetic resolution
Furutani, Toshiyuki,Hatsuda, Masanori,Imashiro, Ritsuo,Seki, Masahiko
, p. 4763 - 4768 (2007/10/03)
Enantiopure 1,1'-binaphthyl-2,2'-dicarboxylic acids (R)-1 and (S)-1 have been synthesized through the lipase-catalyzed kinetic resolution of the racemic 2,2-bis(hydroxymethyl)-1,1'-binaphthyl (±)-2 and subsequent oxidation of the hydroxymethyl groups. (C) 2000 Elsevier Science Ltd.
A Practical Method for Optical Resolution of 1,1'-Binaphtyl-2,2'-dicarboxylic Acid via 1-Phenylethylamides
Oi, Shuichi,Matsuzaka, Yutaka,Yamashita, Junzo,Miyano, Sotaro
, p. 956 - 957 (2007/10/02)
Both enentiomers of 1,1'-binaphthyl-2,2'-dicarboxylic acid (100percent ee's by HPLC) were conveniently obtained in high yields (ca. 80percent of the theory) via fractional crystallization of the (S)-1-phenylethylamide diastereomers of the racemic acid followed by treatment with thionyl chloride and then alkaline hydrolysis
