19641-53-3Relevant articles and documents
Synthesis of the first per(3-deoxy)-cyclooligosaccharide: Hepta(manno-3- deoxy-6-O-t-butyldimethylsilyl)-β-cyclodextrin
Kelly, David R.,Mish'al, Adel K.
, p. 3627 - 3648 (1999)
Reduction of hepta(manno-2,3-anhydro-6-O-t-butyldimethylsilyl)-β- cyclodextrin with lithium triethylborohydride gives hepta(manno-3-deoxy-6-O- t-butyldimethylsilyl)-β-cyclodextrin. This compound plus the hepta(2-O- methyl)- and hepta(2-O-benzyl)-derivativ
Enantioselective addition of organocerium reagents to aldehydes -effects of TADDOL ligand structure
Greeves, Nicholas,Pease, J. Elizabeth,Bowden, Martin C.,Brown, Stephen M.
, p. 2675 - 2678 (1996)
A range of TADDOL organocerium reagents have been prepared and the effect of TADDOL structure on their enantioselective addition to aldehydes has been studied. Copyright
ASYMMETRIC REDUCTION OF ALKYL ARYL KETONES WITH LITHIUM BOROHYDRIDE USING N-BENZOYLCYSTEINE AS CHIRAL LIGAND
Soai, Kenso,Yamanoi, Takashi,Oyamada, Hidekazu
, p. 251 - 254 (1984)
N-Benzoylcysteine, a chiral ligand posessing sulfur donor atom, was found to be highly effective in enentioselective reduction of alkyl aryl ketones with lithium borohydride (up to 92-93percente.e.).
[1,2]-Wittig rearrangement of acetals iii [1]. New 1,2-alkoxyalcohols, 1,2-alkoxyamines and 1,2-dialkoxy compounds as chiral ligands for organomagnesium and organolithium compounds and for lithium aluminum hydride
Gaertner, Peter,Letschnig, Martin,Knollmueller, Max
, p. 867 - 877 (2000)
Eight O-substituted 1,2-diols and one O,N-substituted 1,2-aminoalcohol derived from 2-alkoxyoctahydro-7,8,8-trimethyl-4,7-methanobenzofurans via a [1,2]-Witting rearrangement and subsequent substitution were synthesized and tested as additives for the ena
Reusable cobalt(III) complex catalysts for enantioselective borohydride reduction of ketones
Tsubo, Tatsuyuki,Chen, Hsiu-Hui,Yokomori, Minako,Kikuchi, Satoshi,Yamada, Tohru
, p. 983 - 986 (2013)
A reusable catalytic system was developed for the catalytic enantioselective borohydride reduction of ketones. The optically active 1-chlorovinylketoiminatocobalt(III) complexes were recovered after the reaction by silica gel column chromatography, and th
Asymmetric synthesis of alkylarylcarbinols via reaction of a chiral pinanediol alkylboronic ester with arylmethyl chlorides
Kabalka, George W.,Li, Nan-Sheng,Yu, Su
, p. 3843 - 3846 (1997)
The reaction of arylmethyl chlorides with chiral pinanediol esters of alkylboronic acids in the presence of lithium dicyclohexylamide affords chiral alkylarylcarbinols in good stereochemical yields after oxidation.
Asymmetric Carbonyl Addition and Asymmetric Polymerization Assisted by Axially Chiral Diamines Give Disparate Ligand/Product Configurational Correlations
Kanoh, Shygeyoshi,Muramoto, Hiroki,Maeda, Kazunobu,Kawaguchi, Naotaka,Motoi, Masatoshi,Suda, Hiroshi
, p. 2244 - 2246 (1988)
Organolithium reagents complexed with axially chiral biphenyl-substituted N,N,N',N'-tetramethylethylenediamines (1 and 2) add to aldehydes in good enantioface selectivity.The pattern of the stereoselection, however, disagrees with that of the helical choi
Bio-inspired asymmetric aldehyde arylations catalyzed by rhodium-cyclodextrin self-inclusion complexes
Asahi, Kaoru,Fujiwara, Shin-Ichi,Iwasaki, Takanori,Kambe, Nobuaki,Takahashi, Ryota,Tsuda, Susumu,Ueda, Ryoji,Yamauchi, Hiroki
supporting information, p. 801 - 807 (2022/02/03)
Transition-metal catalysts are powerful tools for carbon-carbon bond-forming reactions that are difficult to achieve using native enzymes. Enzymes that exhibit inherent selectivities and reactivities through host-guest interactions have inspired widesprea
Manganese catalyzed asymmetric transfer hydrogenation of ketones
Zhang, Guang-Ya,Ruan, Sun-Hong,Li, Yan-Yun,Gao, Jing-Xing
supporting information, p. 1415 - 1418 (2020/11/20)
The asymmetric transfer hydrogenation (ATH) of a wide range of ketones catalyzed by manganese complex as well as chiral PxNy-type ligand under mild conditions was investigated. Using 2-propanol as hydrogen source, various ketones could be enantioselectively hydrogenated by combining cheap, readily available [MnBr(CO)5] with chiral, 22-membered macrocyclic ligand (R,R,R',R')-CyP2N4 (L5) with 2 mol% of catalyst loading, affording highly valuable chiral alcohols with up to 95% ee.
Highly Active Cooperative Lewis Acid—Ammonium Salt Catalyst for the Enantioselective Hydroboration of Ketones
Titze, Marvin,Heitk?mper, Juliane,Junge, Thorsten,K?stner, Johannes,Peters, René
supporting information, p. 5544 - 5553 (2021/02/05)
Enantiopure secondary alcohols are fundamental high-value synthetic building blocks. One of the most attractive ways to get access to this compound class is the catalytic hydroboration. We describe a new concept for this reaction type that allowed for exceptional catalytic turnover numbers (up to 15 400), which were increased by around 1.5–3 orders of magnitude compared to the most active catalysts previously reported. In our concept an aprotic ammonium halide moiety cooperates with an oxophilic Lewis acid within the same catalyst molecule. Control experiments reveal that both catalytic centers are essential for the observed activity. Kinetic, spectroscopic and computational studies show that the hydride transfer is rate limiting and proceeds via a concerted mechanism, in which hydride at Boron is continuously displaced by iodide, reminiscent to an SN2 reaction. The catalyst, which is accessible in high yields in few steps, was found to be stable during catalysis, readily recyclable and could be reused 10 times still efficiently working.