103729-97-1Relevant articles and documents
Preparation of several BINOL-based polymeric ligands for the enantioselective addition of triethylaluminium to aromatic aldehydes
Liu, Dacai,Ouyang, Kunbing,Yang, Nianfa
, p. 1018 - 1023 (2016)
The synthesis of several polystyrene-supported BINOL (1,1-binaphthol) ligands via radical polymerization is described. These BINOL-based polymeric ligands were applied to the enantioselective addition of triethylaluminium to aromatic aldehyde in the presence of titanium isopropoxide. The products were obtained with up to 93% enantiomeric excess (ee) in good to excellent yield. The ligands were easily recovered and reused without losing their catalytic activity as well as enantioselectivity.
Ketopinic acid derived bis(hydroxy amides) as cheap, chiral ligands for the enantioselective ethylation of aromatic aldehydes
De Las Casas Engel, Tomas,Maroto, Beatriz Lora,De La Moya Cerero, Santiago
, p. 1717 - 1727 (2010)
Readily accessible, C2- and pseudo-C2-symmetric bis(hydroxy amides), derived from, commercially available (+)-ketopinic acid and protic diamines, are promising, cheap, chiral ligands for the synthetically valuable, enantioselective a
Roadmap towards N-heterocyclic [2.2]paracyclophanes and their application in asymmetric catalysis
Busch, Mark,Cayir, Merve,Nieger, Martin,Thiel, Werner R.,Braese, Stefan
, p. 6108 - 6123 (2013)
A novel family of [2.2]paracyclophane derivatives is described. Different substituted pyrazole, triazole and pyrimidine moieties were introduced to the [2.2]paracyclophane scaffold and the products were characterized spectroscopically and by X-ray structu
Highly enantioselective addition of diethylzinc to aldehydes catalyzed by a new chiral C2-symmetric Ti-diol complex
Yang, Xiao-Wu,Shen, Jian-Heng,Da, Chao-Shan,Wang, Heng-Shan,Su, Wu,Liu, Da-Xue,Wang, Rui,Choi, Michael C.K.,Chan, Albert S.C.
, p. 6573 - 6575 (2001)
A novel C2-symmetric chiral diol was synthesized and was found to catalyze the enantioselective addition of diethylzinc to aldehydes to afford optically active secondary alcohols with ee's up to 99%.
A sequential application of kinetic resolution and polymer-supported scavenging for the isolation of chiral secondary alcohols
Cordova,Tremblay,Clapham,Janda
, p. 5645 - 5648 (2001)
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Engineering catalysts for enantioselective addition of diethylzinc to aldehydes with racemic amino alcohols: Nonlinear effects in asymmetric deactivation of racemic catalysts
Long, Jiang,Ding, Kuiling
, p. 544 - 547 (2001)
Correct additions make a difference: Asymmetric deactivation and asymmetric amplification concepts coupled with a high-throughput screening technique provided a successful strategy for designing a highly enantioselective catalytic system by simple combination of a racemic amino alcohol (rac-DB) and a nonracemic additive (AA). The example in the scheme shows the conversion of 1 into 2 with up to 92.7% ee.
A facile synthesis and the asymmetric catalytic activity of BINOL-based thiazole (thiadiazole) thioether ligands
Dong, Zhi-Bing,Liu, Bing,Fang, Cao,Li, Jin-Shan
, p. 17 - 22 (2008)
Four new BINOL-based thiazole (thiadiazole) thioether ligands (S)-1, (S)-2, (S,S)-3 and (S)-4 were prepared. When their catalytic effectiveness was tested, good results (up to 93% ee and 97% yield) were obtained in the asymmetric addition of diethylzinc to aldehydes while poor results were obtained in the asymmetric conjugate addition of diethylzinc to enones.
The synthesis of N,O-ferrocenyl pyrrolidine-containing ligands and their application in the diethyl- and diphenylzinc addition to aromatic aldehydes
Ahern, Theresa,Mueller-Bunz, Helge,Guiry, Patrick J.
, p. 7596 - 7602 (2006)
(Chemical Equation Presented) A facile route to a series of planar chiral N,O-ferrocenyl pyrrolidine-containing ligands with varying substituents at the nitrogen and oxygen donor atoms is described. The oxygen donor atom was introduced via a diastereoselective ortho-metalation of N-methylpyrrolidinyl and N-allylpyrrolidinyl ferrocene intermediates and was quenched with various ketones. The nitrogen substituent was varied through deallylation and subsequent derivatization of a secondary pyrrolidine. The efficacy of these novel ligands was investigated in the enantioselective addition of diethylzinc and diphenylzinc to aromatic aldehydes. The ligands proved highly effective in the diethylzinc addition to benzaldehyde that resulted in high yields of up to 99% and enantioselectivities (ee's) of up to 95%. The role of planar chirality was explored and the results indicated that the planar chirality, and not the central chirality, of the ferrocenyl ligands was the dominant stereo-controlling element. Employment of a mixed ethyl-phenylzinc reagent in the phenylation of aromatic aldehydes led to a mixture of the two additional products, and the phenylated product was obtained in up to 37% ee.
New chiral ferrocenyloxazolines: The first planar chiral triferrocenylmethane derivative and its use in asymmetric catalysis
Garabatos-Perera, José Ramon,Butensch?n, Holger
, p. 2047 - 2052 (2009)
New planar chiral enantiopure ferrocenyloxazolines have been prepared including ferrocenyldiphenylmethanol, diferrocenylphenylmethanol and triferrocenylmethanol derivatives (S,pR)-10 - (S,pR)-12, the latter being the first chiral triferrocenylmethanol der
Synthetic, structural, NMR and catalytic studies of phosphinic amide-phosphoryl chalcogenides (chalcogen = O, S, Se) as mixed-donor bidentate ligands in zinc chemistry
Del Aguila-Sanchez, Miguel A.,Santos-Bastos, Neidemar M.,Ramalho-Freitas, Maria C.,Garcia Lopez, Jesus,Costa De Souza, Marcos,Camargos-Resende, Jackson A. L.,Casimiro, Maria,Alves-Romeiro, Gilberto,Iglesias, Maria Jose,Lopez Ortiz, Fernando
, p. 14079 - 14091 (2014)
ortho Substituted (diphenylphosphoryl)-, (diphenylphosphorothioyl)- and (diphenylphosphoroselenoyl)-phosphinic amides o-C6H 4(P(X)Ph2)(P(O)NiPr2) (X = O (20a), S (20b), Se (20c)) were synthesized by ortho directed lithiation of N,N-diisopropyl-P,P-diphenylphosphinic amide (Ph2P(O)N iPr2) followed by trapping with Ph2PCl and subsequent oxidation of the o-(diphenylphosphine)phosphinic amide (19) with H2O2, S8 and Se. The reaction of the new mixed-donor bidentate ligands with zinc dichloride afforded the corresponding complexes [ZnCl2(P(X)Ph2)o-C6H 4(P(O)NiPr2)] (21a-c). The new compounds were structurally characterized in solution by nuclear magnetic resonance spectroscopy and in the solid-state by X-ray diffraction analysis of the ligand (20b) and the three complexes (21a-c). The X-ray crystal structure of 20b suggests the existence of a PO→P(S)-C intramolecular nonbonded interaction. The natural bond orbital (NBO) analysis using DFT methods showed that the stabilization effect provided by a nO→σ* P-C orbital interaction was negligible. The molecular structure of the complexes consisted of seven-membered chelates formed by O,X-coordination of the ligands to the zinc cation. The metal is four-coordinated by binding to the two chlorine atoms showing a distorted tetrahedral geometry. Applications in catalysis revealed that hemilabile ligands 20a-c act as significant promoters of the addition of diethylzinc to aldehydes, with 20a showing the highest activity. Chelation of Et2Zn with 20a was evidenced by NMR spectroscopy.
Enantioselective Addition of Diethylzinc to Aldehydes Catalyzed by a Titanate Complex with a Chiral Tetradentate Ligand
Qiu, Jin,Guo, Cheng,Zhang, Xumu
, p. 2665 - 2668 (1997)
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The synthesis of a novel non-C2 symmetric H4-BINOL ligand and its application to titanium-catalyzed enantioselective addition of diethylzinc to aldehydes
Shen, Xiaoqiang,Guo, Hui,Ding, Kuiling
, p. 4321 - 4327 (2000)
The synthesis of the novel non-C2 symmetric ligand (R)-5,6,7,8-tetrahydro-1,1'-binaphthol has been achieved via partial reduction of 2,2'-bis(methoxymethoxy)-1,1'-binaphthyl with Raney Ni-Al alloy in dilute aqueous NaOH solution followed by hyd
Enantioselective alkylation of aldehydes catalyzed by a highly active titanium complex of 3-substituted unsymmetric BINOL
Harada, Toshiro,Kanda, Kousou
, p. 3817 - 3819 (2006)
A titanium complex derived from 3-(3,5-diphenylphenyl)-BINOL exhibits an enhanced catalytic activity in the asymmetric alkylation of aldehydes, allowing the reduction of the catalyst amount to less than 1 mol % without deterioration in enantioselectivity.
A practical o-hydroxybenzylamines promoted enantioselective addition of dialkylzincs to aldehydes with asymmetric amplification
Palmieri, Gianni
, p. 3361 - 3373 (2000)
The addition of dialkylzincs to aldehydes is accelerated considerably by the presence of a catalytic amount of o-hydroxybenzylamine (R,R)-2e to give, after hydrolysis, the corresponding alcohol (S)-9 in good enantiomeric purity. The origins of the enantioselection have been elucidated. A strong positive nonlinear relationship was observed for the reaction enantioselctivity with the use of o-hydroxybenzylamine 2e, which is very accessible through a short stereoselective synthetic route. The enantiomeric purity of the product 9 is much higher than the d.e. of the chiral source 2e, and the rate of the enantioselective catalysis increases considerably with the increase of the d.e. of (R,R)-2e. Copyright (C) 2000 Elsevier Science Ltd.
Asymmetric catalytic alkylation of aldehydes with diethylzinc using a chiral binaphthol-titanium complex
Mori, Maki,Nakai, Takeshi
, p. 6233 - 6236 (1997)
The asymmetric catalytic alkylation of aldehydes with diethylzinc using (R)- BINOL-Ti(O-i-Pr)2 complex as an asymmetric precatalyst is shown to afford the corresponding secondary alcohols in a high enantioselectivity (up to 86% ee).
Enantioselective addition of diethylzinc to aldehydes using 1,1′-bi-2-naphthol-3,3′-dicarboxamide as a chiral auxiliary
Kitajima, Hiroshi,Ito, Katsuji,Katsuki, Tsutomu
, p. 343 - 344 (1996)
A highly enantioselective addition of diethylzinc to a wide range of aldehydes was achieved by using N,N,N′,N′-tetraalkyl-1,1′-bi-2-naphthol-3,3′- dicarboxamides as chiral auxiliaries.
Practical and highly enantioselective alkylation of aldehydes catalyzed by a titanium complex of 3-aryl H8-BINOL
Harada, Toshiro,Ukon, Takahiro
, p. 2499 - 2502 (2007)
A titanium complex derived from 3-(3,5-diphenylphenyl)-H8-BINOL exhibits high catalytic activity and enantioselectivity in the alkylation of aldehydes. Enantioselectivities comparable to or higher than 20 mol % of the parent H8-BINOL
Chiral thiazolidines in the enantioselective ethylation of aldehydes: An experimental and computational study
Tavares, Nélia C.T.,Neves, César T.,Milne, Bruce F.,Murtinho, Dina,Pais, Alberto A.C.C.,Serra, M. Elisa Silva
, p. 1 - 10 (2018)
A library of new chiral thiazolidines was prepared starting from L-cysteine and D-penicillamine in a simple, one-step procedure. 2-Arylthiazolidines were obtained, as diastereoisomeric mixtures, with good yields and in short reaction times, through a new and greener procedure, using microwave irradiation. Their use as chiral ligands in the enantioselective ethylation of aromatic aldehydes was studied and optimized, originating good to excellent conversions and ee up to 94% in 6 h. A series of heteroaromatic and aliphatic substrates were also enantioselectively ethylated with success, with ee up to 77%. The distinct opposite chirality in L-cysteine and D-penicillamine makes the use of these ligands an interesting approach for obtaining both the (S) and (R) enantiomers of the chiral alcohols, compounds with potential applications in the area of fine chemistry. NMR studies were carried out using a diastereoisomeric mixture of thiazolidines, allowing the identification of the most stable structure. Computational studies confirmed this result and also gave important insight into the species involved in the catalytic cycle of the enantioselective alkylation.
Synthesis of C2-symmetrical bis-β-amino alcohols and their application in the enantioselective addition of diethylzinc to aldehydes
Xu, Qianyong,Wang, Hui,Pan, Xinfu,Chan, Albert S.C,Yang, Teng-Kuei
, p. 6171 - 6173 (2001)
The C2-symmetrical bis-β-amino alcohols 1-6 were prepared and especially attention is focused on bridges, which link the two β-amino alcohol units. These ligands have been applied as chiral catalysts in the asymmetric addition of diethylzinc to aldehydes. sec-Alcohols have been obtained in good yields with up to 95.4% enantiomeric excess.
Modular amino acid amide chiral ligands for enantioselective addition of diethylzinc to aromatic aldehydes
Gou, Shaohua,Ye, Zhongbin,Chang, Jing,Gou, Guangjun,Feng, Mingming
, p. 448 - 453 (2011)
Enantioselective addition of diethylzinc to a series of aromatic aldehydes was developed using a modular amino acid amide chiral ligand (2S)-3-phenyl-N-((R)-1-phenyl-ethyl)-2-(tosylamino)propanamide without using titanium complex. The catalytic system employing 10 mol% of 1g was found to promote the addition of diethylzinc (ZnEt2) to a wide range of aromatic aldehydes with electron-donating and electron-withdrawing substituents, giving up to 82% ee of the corresponding secondary alcohol under mild conditions.
A new Ferrocene in the Asymmetric Addition of Diethylzinc to Aldehydes
Bolm, Carsten,Mu?iz Fernández, Kilian,Seger, Andreas,Raabe, Gerhard
, p. 1051 - 1052 (1997)
The use of a new ferrocene in the asymmetric addition of diethylzinc to aldehydes is reported. Secondary alcohols with enantioselectivities of up to 95% ee are obtained.
Design of novel chiral N,N,O-tridentate phenanthroline ligands and their application to enantioselective addition of organozinc reagents to aldehydes
Naganawa, Yuki,Namba, Tomoya,Aoyama, Tomotaka,Shoji, Kentaro,Nishiyama, Hisao
, p. 13224 - 13227 (2014)
The novel N,N,O-tridentate phenanthroline ligand (BinThro) bearing an axially chiral binaphthyl backbone prepared from BINOL was found to be an effective chiral catalyst for enantioselective addition of diethylzinc to aromatic aldehydes with high enantios
A novel trinuclear titanium(IV) complex with a C3 axis along Ti1-Ti2-Ti3 containing 3-[(1H-1,2,4-triazol-1-yl)methyl]-BINOLate ligands: synthesis, structure, and reactivity
Liu, Bing,Jiang, Fu-Yong,Song, Hai-Bin,Li, Jin-Shan
, p. 2149 - 2153 (2006)
A new modified BINOL, (S)-3-[(1H-1,2,4-triazol-1-yl)methyl]-1,1′-binaphthol, was prepared. In the presence of titanium tetraisopropoxide, this ligand showed moderate catalytic properties for the asymmetric addition of diethylzinc to aldehydes. By treating rac-3-[(1H-1,2,4-triazol-1-yl)methyl]-1,1′-binaphthol with excess titanium tetraisopropoxide, a novel trinuclear titanium(IV) complex was obtained. A C3 axis along Ti1-Ti2-Ti3 is present in the molecule.
The synthesis of new optically active 2-methylquinoline derivatives and their application in the enantioselective addition of diethylzinc to aldehydes
Xu, Qianyong,Wang, Guoxing,Pan, Xinfu,Chan, Albert S.C.
, p. 381 - 385 (2001)
Homochiral 2-methylquinoline derivatives have been synthesized and applied in the enantioselective addition of diethylzinc to aldehydes. Good yields and enantiomeric excesses of up to 91.4% were observed in these reactions.
Novel C2-symmetric 1,1′-disubstituted ferrocenyl aziridino alcohol ligands: Remarkable improvement of enantioselectivity in the catalytic asymmetric addition of diethylzinc to aldehydes
Wang, Min-Can,Hou, Xue-Hui,Xu, Cui-Lian,Liu, Lan-Tao,Li, Gui-Lan,Wang, De-Kun
, p. 3620 - 3626 (2005)
A series of novel chiral C2-symmetric 1,1′-disubstituted ferrocenyl aziridino alcohols have been readily synthesized and applied as catalysts to promote enantioselective addition of diethylzinc to aldehydes affording the corresponding 1-propano
2,2′-Bipyridine-α,α′-trifluoromethyl-diol ligand: Synthesis and application in the asymmetric Et2Zn alkylation of aldehydes
Lauzon, Samuel,Ollevier, Thierry
supporting information, p. 11025 - 11028 (2021/11/03)
A chiral 2,2′-bipyridine ligand (1) bearing α,α′-trifluoromethyl-alcohols at 6,6′-positions was designed in five steps affording either the R,R or S,S enantiomer with excellent stereoselectivities, i.e. 97% de, >99% ee and >99.5% de, >99.5% ee, respectively. The key step for reaching high levels of stereoselectivity was demonstrated to be the resolution of the α-CF3-alcohol using (S)-ibuprofen as the resolving agent. An initial application for the 2,2′-bipyridine-α,α′-CF3-diol ligand was highlighted in the ZnII-catalyzed asymmetric ethylation reaction of aromatic, heteroaromatic, and aliphatic aldehydes. Synergistic electron deficiency and steric hindrance properties of the newly developed ligand afforded the corresponding alcohols in good to excellent yields (up to 99%) and enantioselectivities (up to 95% ee). As observed from single crystal diffraction analysis, the complexation of the 2,2′-bipyridine-α,α′-CF3-diol ligand generates an unusual hexacoordinated ZnII.
A Heck reaction/photochemical alkene isomerization sequence to prepare functionalized quinolines
Donohoe, Timothy J.,Hoff, Oskar,Hoffman, Jack B.,Kelly, Alex,Walker, Johannes C. L.,Werrel, Simon
, (2020/08/06)
A route to prepare functionalized quinolines based on a Heck reaction/UV-induced alkene isomerization sequence is described. The method allows for the preparation of quinolines under mild and neutral conditions and has broad functional group tolerance. Acid-sensitive functional groups that would not be tolerated under previous approaches can be included and a one-pot quinoline forming procedure is also reported.
