112777-66-9Relevant articles and documents
Synthesis and application of 3,3′-diarylmethyl BINOLs
Zhang, Yi-Li,Zhang, Feng,Tang, Wei-Jun,Wu, Qing-Lai,Fan, Qing-Hua
, p. 1250 - 1254 (2006)
A new class of 3,3′-diarylmethyl BINOL derivatives were synthesized and applied to the catalytic asymmetric addition of diethylzinc to aldehydes. These chiral diol auxiliaries could be used as catalysts without the addition of Ti(i-PrO)4 and showed unprecedented catalytic activities and enantioselectivities (up to 94% ee, 5 mol% catalyst loading). Georg Thieme Verlag Stuttgart.
Single-crystal to single-crystal cross-linking of an interpenetrating chiral metal-organic framework and implications in asymmetric catalysis
Ma, Liqing,Wu, Chuan-De,Wanderley, Marcela M.,Lin, Wenbin
, p. 8244 - 8248 (2010)
Support framework: Post-synthesis modification of an interpenetrating Zn-based chiral metal-organic framework with Ti(OiPr)4 results in a Lewis acidic catalyst (see picture; gray C, white H, red O, green Ti) with modest enantioselectivity in the asymmetric addition of diethylzinc to aldehydes. The Ti(OiPr)4-treated framework contains single-crystal to single-crystal cross-linking of the two interpenetrating networks.
A series of isoreticular chiral metalg-organic frameworks as a tunable platform for asymmetric catalysis
Ma, Liqing,Falkowski, Joseph M.,Abney, Carter,Lin, Wenbin
, p. 838 - 846 (2010)
Metalg-organic frameworks, built by bridging metal ions with organic linkers, represent a new class of porous hybrid materials with attractive tunability in compositions, structures and functions. In particular, the mild conditions typically employed for their synthesis allow for the functionalization of their building blocks, and thus the rational design of novel materials. Here we demonstrate the systematic design of eight mesoporous chiral metalg-organic frameworks, with the framework formula [LCu 2(solvent)2] (where L is a chiral tetracarboxylate ligand derived from 1,1'2-bi-2-naphthol), that have the same structures but channels of different sizes. Chiral Lewis acid catalysts were generated by postsynthesis functionalization with Ti(OiPr)4, and the resulting materials proved to be highly active asymmetric catalysts for diethylzinc and alkynylzinc additions, which converted aromatic aldehydes into chiral secondary alcohols. The enantioselectivities of these reactions can be modified by tuning the size of the channels, which alters the diffusion rates of the organic substrates.
Aziridinylethers as highly enantioselective ligands for the asymmetric addition of organozinc species to carbonyl compounds
Pieczonka, Adam M.,Les?niak, Stanis?aw,Jarzyński, Szymon,Rachwalski, Micha?
, p. 148 - 151 (2015)
In the present paper a straightforward and efficient method for the synthesis of new chiral aziridinylether systems has been described. All of the new compounds have been tested in two stereocontrolled addition reactions of organozinc species to carbonyl compounds. The addition of diethyl- and phenylethynylzinc to aryl and alkyl aldehydes afforded the corresponding chiral products in high chemical yields (up to 90%) and with excellent ee's of approximately 93%.
Synthesis of quinazolinone-based aziridine diols as chiral ligands: Dual stereoselectivity in the asymmetric ethylation of aryl aldehydes Dedicated to Professor Dr. Metin Balci on the occasion of his retirement
Celik, Saffet,Cakici, Murat,Kilic, Hamdullah,Sahin, Ertan
, p. 152 - 157 (2015)
A new class of quinazoline-based enantiomerically pure aziridine diols 4a-d were prepared from the aziridination of mesityl oxide 3 with in situ generated 3-acetoxyaminoquinazolinone (S)-2b followed by NaBH4 reduction. Aziridine diols 4a-d were purified by means of column chromatography on silica gel and their stereochemistries were assigned by X-ray crystallography and NMR analysis. These aziridine diols 4 were evaluated as chiral ligands in the asymmetric addition of diethylzinc to aryl aldehydes, and ligand (S,R,R)-4a yielded (R)-1-phenylpropanol derivatives with up to 92% ee, while the diastereomer (S,S,R)-4c gave the opposite enantiomers (S)-1-phenylpropanol derivatives with up to 86% ee. The results demonstrate that switching the configuration of the aziridine alcohol moiety in ligand gives a remarkable reversal of enantioselectivity in the asymmetric addition of diethylzinc to aryl aldehydes.
Synthesis and characterization of mesoporous zirconium phosphonates: A novel supported cinchona alkaloid catalysts in asymmetric catalysis
Ma, Xuebing,Wang, Yonghua,Wang, Wei,Cao, Jun
, p. 401 - 407 (2010)
In this paper, cinchonidine (CD) with the different arm lengths (n = 2-6) was covalently immobolized onto the backbone of zirconium phosphonate to afford a series of mesoporous zirconium phosphonates (4a-e) for the first time. It was found that zirconium phosphonates (4a-e) were conglomerated with the globular aggregates with the diameters of about 100-150 nm and possessed the surface areas of 20.8-36.2 m2 g-1, pore volumes of 0.219-0.498 cc g-1 and average pore sizes of 11.7-41.5 ?. The TEM images of 4a-e in organic solvent showed that these materials were easily swollen into the filiform structure with the length about several micrometers and thickness about 30-50 nm. In the field of the asymmetric catalysis, the preliminarily enantioselective addition of diethylzinc to various aldehydes catalyzed by 4a-e (35-62%e.e. in the 68-92% yield) was carried out and can be reused ten times without loss in the yield and enantiomeric excess.
The influence of microwave irradiation on lipase-catalyzed kinetic resolution of racemic secondary alcohols
Bachu, Prabhakar,Gibson, Jennifer S.,Sperry, Jonathan,Brimble, Margaret A.
, p. 1618 - 1624 (2007)
The influence of microwave irradiation on the Novozyme 435 (Candida antarctica lipase) catalyzed kinetic resolution of secondary alcohols with different functional groups was studied in comparison to the use of conventional heating at 60 °C. p-Chlorophenyl acetate was used as an acyl donor and toluene as the solvent. (±)-1-Phenyl-1-propanol 1, (±)-1-(4-bromophenyl)-propan-1-ol 3, (±)-1-phenylbut-3-en-1-ol 5 and (±)-3-bromo-2-(2-hydroxypropyl)-1,4-dimethoxynaphthalene 7 were successfully resolved into their (S)-alcohols and (R)-esters, respectively, in good enantiomeric excess. Resolution of (±)-ethyl-5-(4-methoxybenyloxy)-3-hydroxypentanoate 9 afforded its (R)-alcohol and (S)-ester using this method. In addition, microwave-assisted lipase transesterification of meso-symmetric diol 11 effected desymmetrization to ester 12 with high enantiomeric excess. In all cases studied, the conversion value for the microwave-assisted lipase kinetic resolution of secondary alcohols was higher than that obtained using conventional heating.
Observation of hyperpositive non-linear effect in catalytic asymmetric organozinc additions to aldehydes
Geiger, Yannick,Achard, Thierry,Maisse-Fran?ois, Aline,Bellemin-Laponnaz, Stéphane
supporting information, p. 1250 - 1256 (2020/07/25)
Asymmetric amplification is a phenomenon that is believed to play a key role in the emergence of homochirality in life. In asymmetric catalysis, theoretical and experimental models have been investigated to provide an understanding of how chiral amplification is possible, in particular based on non-linear effects. Interestingly, it has been proposed a quarter century ago that chiral catalysts, when not enantiopure might even be more enantioselective than their enantiopure counterparts. We show here that such hyperpositive non-linear effect in asymmetric catalysis is indeed possible. An in-depth study into the underlying mechanism was carried out, and the scheme we derive differs from the previous proposed models.
SECONDARY ARYL ALCOHOL AND METHOD OF SYNTHESIZING THEREOF
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Paragraph 0032; 0070-0072, (2020/05/13)
The present invention relates to secondary aryl alcohol and a method for synthesizing the same and, specifically, to synthesizing secondary aryl alcohol having high optical selectivity through a hydrosilylation reaction using ketone containing an aryl group. In the method for synthesizing secondary aryl alcohol according to an embodiment of the present invention, secondary aryl alcohol is synthesized by making ketone react with hydrosilane under a chiral boron Lewis acid catalyst.COPYRIGHT KIPO 2020
