Optisch aktive 9,9′‐Spirobifluoren‐Derivate

Haas, Georges; Prelog, V.

doi:10.1002/hlca.19690520505

Cited by 91 publications

(47 citation statements)

References 12 publications

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“…Similarly, the same Friedländer reaction of the diketone 6 [2] with a series of o-aminoarenecarbaldehydes afforded the corresponding ligands 7 in 75%-82% yields. The prerequisite ketones 3 and 6 were prepared by polyphosphoric acid (PPA)-catalyzed Friedel-Crafts acylation of known 4-[9,9'-spirobi(fluoren)-7-yl]butanoic acid (2) and 4,4'-(9,9'-spirobi[fluorene]-7,7'-diyl)dibutanoic acid [2] in 70% and 78% yields, respectively.…”

Section: Synthesismentioning

confidence: 91%

“…The prerequisite ketones 3 and 6 were prepared by polyphosphoric acid (PPA)-catalyzed Friedel-Crafts acylation of known 4-[9,9'-spirobi(fluoren)-7-yl]butanoic acid (2) and 4,4'-(9,9'-spirobi[fluorene]-7,7'-diyl)dibutanoic acid [2] in 70% and 78% yields, respectively.…”

Section: Synthesismentioning

confidence: 99%

“…A nitrogen flow rate for the each scanning calorimetric run was 50 mL/min. The starting 4-[9,9'-spirobi(fluoren)-7-yl]butanoic acid (2) [2], o-aminoarenecarbaldehydes [26][27][28], and diketone (6) [2] were prepared by employing previously reported methods. Chemicals and solvents were of commercial reagent grade and used without further purification.…”

Section: Generalmentioning

confidence: 99%

“…9,9'-Spirobifluorene (1) as well as its derivatives have been of interest due to their characteristic structures [1], of which the early studies were focused not only on the molecular recognition of various α-aminoalcohols by 9,9'-spirobifluorene-based crown ethers [2,3] and of monosaccharides by dendritic cleft receptors [4][5][6], but also on the inclusion of compounds with hydrocarbons [7], carbohydrates [8,9], and α-hydroxycarboxylates [10]. However, interest in 9,9'-spirobifluorenes, especially 9,9'-spirobifluorenebased oligomers, as well as polymers has recently switched to applications in molecular electronic devices for light emitting devices [11][12][13][14][15][16], hybrid porous solid [17] and catalysis [18].…”

Section: Introductionmentioning

confidence: 99%

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Synthesis and Properties of Annulated 2-(Azaar-2-yl)- and 2,2'-Di(azaar-2-yl)-9,9'-spirobifluorenes

2013

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A series of 9,9'-spirobifluorene-derived N-heterocycles were prepared by the reactions of 8,9-dihydrospiro(benzo [b]fluorene-11,9'-fluoren)-6(7H)-one and 8, 8',9,9'-tetrahydro-11,11'-spirobi(benzo[b]fluorene)-6,6'(7H,7'H)-dione with a series of 2-aminoarenecarbaldehydes such as 2-aminobenzaldehyde, 2-aminonicotinealdehyde, 1-amino-2-naphthaldehyde, and 8-aminoquinoline-7-carbaldehyde. In addition to the absorption maxima based on the parent 9,9'-spirobifluorene skeleton in the 225-234, 239-280, 296-298, and 308-328 nm regions, the absorptions due to the π-π* transitions of the heterocycles were observed in the 351-375 nm region in the UV absorption spectra. All the compounds showed strong photoluminescences in the 390-430 nm region.

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Section: Synthesismentioning

confidence: 91%

Section: Synthesismentioning

confidence: 99%

Section: Generalmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Synthesis and Properties of Annulated 2-(Azaar-2-yl)- and 2,2'-Di(azaar-2-yl)-9,9'-spirobifluorenes

2013

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“…O conceito de cicloestereoisomerismo foi cunhado baseado na quiralidade bidimensional dos anéis, e aplicado inicialmente a cicloalaninas enantioméricas (14,15), preparadas pelos russos Hans Gerlach e Yuri Ovchinnikov 57 . Seguiu daí para estudos sobre pseudoassimetria e enantioisomerismo geométrico e os exemplificou através da sín-tese de 16-18 58,59 . Prelog sempre se mostrou um homem sensível, com um fino humor e muito colaborativo.…”

Section: Figura 6 Reações Transanulares Observadas Por Prelog E Colaunclassified

Vladimir Prelog e a estereoquímica das moléculas orgânicas: um centenário de nascimento

Rezende¹

2007

Quím. Nova

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Recebido em 25/7/06; aceito em 9/11/06; publicado na web em 28/5/07 VLADIMIR PRELOG AND THE STEREOCHEMISTRY OF ORGANIC MOLECULES: A CENTENARY OF BIRTH. The Croatian chemist Vladimir Prelog shared in 1975 the Nobel Prize in chemistry with J. W. Cornforth for his research into the stereochemistry of organic molecules and reactions. His studies gave new horizons to the comprehension of steric effects on the reactivity of mediumsized rings, to conformational analysis and to the stereospecificity associated to asymmetric syntheses. Prelog made important contributions to enzyme chemistry and to the structure elucidation of alkaloids and of antibiotics from microorganisms, but probably his most famous work is the CIP system for assigning the stereochemistry of chiral centers. Na Figura 1 pode-se ver a imagem de uma mulher, concebida pelo pintor suíço Hans Erni, a pedido de Prelog, e que recebeu o nome de "Rassi-maid", em alusão a "racemate", palavra inglesa usada para designar uma mistura equimolar de um par de enantiômeros e que não exibe atividade ótica. Esta gravura foi oferecida por Prelog aos colegas e amigos em agradecimento às homenagens recebidas na ocasião da premiação do Nobel.Segundo Prelog, para compreender a estereoquímica com base no fenômeno da quiralidade, seria necessário unir a inteligência humana, as mãos esquerda e direita e os dois objetos assimétricos mais simples do espaço tridimensional, os tetraedros enantiomorfos.O termo quiral vem do grego cheir, que significa mão, o mais familiar dos objetos assimétricos. Uma figura quiral não se sobrepõe a sua imagem no espelho e ambas são chamadas de enantiomorfos ou enantiômeros. Reconhecemos bem este fenômeno quando tentamos ler uma palavra pelo espelho retrovisor do automóvel. Com certa curiosidade, percebemos que esta imagem é contrária à que observamos diretamente. Prelog bem retratou esta visão ao assinar, em 1966, de trás para frente, a Declaração de Bürgenstock (Figura 2), na segunda reunião da EUCHEM Conference on Stereochemistry, mais conhecida como Bürgenstock Conference, um dos mais conceituados encontros científicos mundiais sobre estereoquímica e que ocorre na Suíça. Foi lá que Cahn, Ingold e Prelog formularam as regras da nomenclatura absoluta R e S 1 .Prelog nasceu em 1906, em Sarajevo, província da Bósnia pertencente à monarquia austro-húngara. Em 1914, viveu um episó-dio que marcou sua vida. Ainda menino, fora incumbido pela escola de portar-se em um cordão de isolamento durante a visita do arquiduque, o Príncipe Ferdinand e sua esposa, que chegariam de carruagem. Prelog deveria espalhar flores à frente da comitiva. Durante o evento teve o choque de presenciar o assassinato do prín-cipe, fato que o tornou totalmente avesso às manifestações mais violentas de qualquer causa ou natureza.Iniciou seus estudos na cidade de Zagreb, capital da Croácia, no ano de 1915, aos cuidados de uma tia paterna após a separação de seus pais. Já aos 12 anos teve o primeiro contato com as ciênci-as da experimentação realizando no laboratório da escola práticas...

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Preparation of 1-O-acylglucuronides of 13C-labelled (R)- and (S)-ketoprofens

Akira

Taira

Hasegawa

et al. 1997

J Label Compd Radiopharm

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The preparation of enantiomeric [1‐13C]ketoprofens (KPs) and their acylglucuronides has been reported for the nuclear magnetic resonance (NMR) spectroscopic studies on the stereoselective pharmacokinetics and reactivities of KP acylglucuronides. The racemic [1‐13C]KP was prepared by a three‐step synthetic scheme from [13C]potassium cyanide in overall yield of 23 %. The racemate was optically resolved by the formation of diastereomeric amides with (R)‐(+)‐α‐phenylethylamine, separation of the amides by column chromatography on silica gel, and nonhydrolytic cleavage of the amide bond using nitrogen tetroxide. The yields of KP enantiomers were 30 % based on the racemate. The acylglucuronides of (R)‐ and (S)‐[1‐13C]KP were isolated from human urine after dosing of each labelled KP (100 mg) using preparative high‐performance liquid chromatography following Sep‐Pak C18 pretreatments. The yields of the conjugates from 0–4 h post‐dose urine were roughly 50 mg. © 1997 John Wiley & Sons, Ltd.

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Optisch aktive 9,9′‐Spirobifluoren‐Derivate

Cited by 91 publications

References 12 publications

Synthesis and Properties of Annulated 2-(Azaar-2-yl)- and 2,2'-Di(azaar-2-yl)-9,9'-spirobifluorenes

Synthesis and Properties of Annulated 2-(Azaar-2-yl)- and 2,2'-Di(azaar-2-yl)-9,9'-spirobifluorenes

Vladimir Prelog e a estereoquímica das moléculas orgânicas: um centenário de nascimento

Preparation of 1-O-acylglucuronides of 13C-labelled (R)- and (S)-ketoprofens

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