Enantioselective additions of diphenylzinc to aldehydes using chiral pyrrolidinylmethanol derivatives as catalysts

Zhao, Gang; Li, Xiang Guo; Wang, Xiu-Ran

doi:10.1016/s0957-4166(01)00074-x

Cited by 63 publications

(14 citation statements)

References 15 publications

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“…Next, we examined the performance of the fluorous amino alcohol 5 in phenyl transfer reactions to an aromatic aldehyde 13. Recently, Zhao et al reported enantioselective phenylations using pyrrolidinylmethanol derivatives 9. Various ( S )‐proline‐derived amino alcohols were examined and the best enantioselectivity (92.6 % ee , at −30 °C) was achieved with 15 mol % of 6 , pure Ph 2 Zn and a slow addition of the substrate ( p ‐chlorobenzaldehyde).…”

Section: Resultsmentioning

confidence: 99%

“…The first application of a diethylzinc addition in FBS was reported by Kleijn et al5a and since then several similar approaches have been detailed by Nakamura et al5b, d, f and Tian et al,5c, e who employed fluorous chiral binaphthol derivatives and fluorous chiral amino alcohols, respectively. Herein, we wish to present an effective perfluoro catalyst for diorganozinc addition reactions based on the modification of pyrrolidinylmethanol8, 9 derivatives. We chose the perfluoro‐prolinol system 5 due to the high enantioselectivity described for reactions involving known prolinol derivatives.…”

Section: Introductionmentioning

confidence: 99%

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Asymmetric Diethyl‐ and Diphenylzinc Additions to Aldehydes by Using a Fluorine‐Containing Chiral Amino Alcohol: A Striking Temperature Effect on the Enantioselectivity, a Minimal Amino Alcohol Loading, and an Efficient Recycling of the Amino Alcohol

Park

Lee

Bolm

et al. 2005

Chemistry A European J

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A chiral pyrrolidinylmethanol derivative containing perfluoro-ponytails (5) was prepared from (S)-proline. The use of this perfluoro-substituted amino alcohol in catalytic asymmetric additions of organozinc reagents to aldehydes affords products with high enantioselectivities in both pure hexane and a mixture of hexane and FC-72 (perfluorohexane). Enantiomeric excesses up to 94 and 88 % ee have been achieved in Et(2)Zn and Ph(2)Zn additions, respectively. For the reactions in the biphasic solvent system a striking temperature effect was observed. Thus, when the temperature was raised from 0 to 40 degrees C the ee value of the product increased from 81 to 92 %. Furthermore, the catalyst loading could be remarkably low, and with only 0.1 mol % of amino alcohol 5 a product with 90 % ee was obtained in the Et(2)Zn addition to benzaldehyde in hexane. The perfluoro-ligand was easily recovered by simple phase separation, and until the ninth repetition its reuse proceeded without significant loss of enantioselectivity and reactivity.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Asymmetric Diethyl‐ and Diphenylzinc Additions to Aldehydes by Using a Fluorine‐Containing Chiral Amino Alcohol: A Striking Temperature Effect on the Enantioselectivity, a Minimal Amino Alcohol Loading, and an Efficient Recycling of the Amino Alcohol

Park

Lee

Bolm

et al. 2005

Chemistry A European J

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“…Yields in the phenylation reaction with DAIB ranged from 53% to 91%. In contrast to the phenylation of ketones, several highly enantioselective catalysts have been developed for the asymmetric addition of phenyl groups to aldehydes (14)(15)(16)(17)(18)(19)(20).…”

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confidence: 99%

Catalytic asymmetric addition of diphenylzinc to cyclic α,β-unsaturated ketones

García

Walsh

2004

Proc. Natl. Acad. Sci. U.S.A.

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We have examined the use of our bis(sulfonamide) diol ligand (1) in the asymmetric addition of phenyl groups to cyclic ␣,␤-unsaturated ketones. Good to excellent enantioselectivities have been obtained with cyclic enones bearing alkyl substituents in the 2 position (71-97% enantiomeric excess). Furthermore, excellent enantioselectivities have been observed in the asymmetric phenylation of cyclic enones with 2-iodo and 2-bromo substituents. The results of this study broaden the scope of the asymmetric additions to ketones promoted by the titanium catalyst derived from ligand 1.alkylation ͉ tertiary alcohols ͉ zinc ͉ titanium ͉ asymmetric catalysis W e recently developed a highly enantioselective titanium catalyst based on the bis(sulfonamide) diol ligand 1 (Fig. 1) for the asymmetric addition of alkylzinc reagents to ketones (Eq. 1; ref. 1). When cyclic ␣,␤-unsaturated ketones were used as substrates, we found that the asymmetric addition reaction could be coupled with a diastereoselective epoxidation by using molecular oxygen as the oxidant to provide a one-pot synthesis of epoxy alcohols with high enantio-and diastereoselectivity (Eq. 2; ref. 2). These studies provide a solution to a long-standing problem in synthetic organic chemistry: the catalytic synthesis of tertiary alcohols from ketones with high enantioselectivity. Unlike related additions of dialkylzinc reagents to aldehyde substrates, which are promoted by hundreds of catalysts (3, 4), only a few systems will catalyze alkyl additions to ketones (1, 2, 5-8), and most of them use high catalyst loadings and long reaction times (6-8).The successful use of ligand 1 in the alkyl additions to ketones led our group (9) and Yus and coworkers (10) to examine the enantioselective phenylation of acyclic ketones with ZnPh 2 . The only previous results in the catalytic asymmetric phenylation of ketones were reported by Dosa and Fu in 1998 (11). In this pioneering work, these authors used Noyori's amino alcohol ligand, (ϩ)-3-exo-(dimethylamino)isoborneol [(ϩ)-DAIB] (12, 13), and diphenylzinc (3.5 eq). Initially, the reaction gave low yields and moderate enantioselectivities. It was found, however, that addition of 1.5 eq of methanol to the diphenylzinc resulted in formation of a mixed alkoxy phenyl zinc reagent that led to increased yields and enantioselectivities (Eq. 3) (11). Under these conditions, excellent enantioselectivities were obtained with substituted propiophenones [86-91% enantiomeric excess (ee)], and acetophenone derivatives afforded enantioselectivities as high as 80%. In the case of cyclohexyl methyl ketone and 3-methyl-2-butanone, the reaction proceeded with 75% and 60% enantioselectivities, respectively. Yields in the phenylation reaction with DAIB ranged from 53% to 91%. In contrast to the phenylation of ketones, several highly enantioselective catalysts have been developed for the asymmetric addition of phenyl groups to aldehydes (14-20).In our initial study on the addition of diphenylzinc to acyclic ketones with ligand 1, we found that enantio...

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“…Moreover, asymmetric addition of organozinc to aldehydes is probably the most successful and still vigorously pursued area in asymmetric C-C bond formation [9,10,11,12,13]. Despite of the enormous success of chiral ligands in asymmetric reactions, a limited number of amides with 1,1'-biaryl backbones are reported for the organozinc addition [14,15,16,17,18,19,20,21,22]. In addition, the rational design of new chiral ligands for enantioselective conjugate alkylation has achieved limited success, presumably due to several factors that have to be taken into consideration.…”

Section: Introductionmentioning

confidence: 99%

Synthesis and Characterization of Some New C2 Symmetric Chiral Bisamide Ligands Derived from Chiral Feist’s Acid

et al. 2012

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The hemilabile chiral C 2 symmetrical bidentate substituted amide ligands (1 R ,2 R )- 5 a-d and (1 S ,2 S )- 6 a-d were synthesized in quantitative yield from (1 R ,2 R )-(+)-3-methylenecyclo-propane-1,2-dicarboxylic acid (1 R ,2 R )- 3 and (1 S ,2 S )-(-)-3-methylene-cyclopropane-1,2-dicarboxylic acid (1 S ,2 S )- 3 , in two steps, respectively. The chiral Feist’s acids (1 R ,2 R )- 3 and (1 S ,2 S )- 3 were obtained in good isomeric purity by resolution of trans -(±)-3-methylene-cyclopropane-1,2-dicarboxylic acid from an 8:2 mixture of tert -butanol and water, using ( R )-(+)- α -methylbenzyl amine as a chiral reagent. This process is reproducible on a large scale. All these new synthesized chiral ligands were characterized by 1 H-NMR, 13 C-NMR, IR, and mass spectrometry, as well as elemental analysis and their specific rotations were measured. These new classes of C 2 symmetric chiral bisamide ligands could be of special interest in asymmetric transformations.

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Enantioselective additions of diphenylzinc to aldehydes using chiral pyrrolidinylmethanol derivatives as catalysts

Cited by 63 publications

References 15 publications

Asymmetric Diethyl‐ and Diphenylzinc Additions to Aldehydes by Using a Fluorine‐Containing Chiral Amino Alcohol: A Striking Temperature Effect on the Enantioselectivity, a Minimal Amino Alcohol Loading, and an Efficient Recycling of the Amino Alcohol

Asymmetric Diethyl‐ and Diphenylzinc Additions to Aldehydes by Using a Fluorine‐Containing Chiral Amino Alcohol: A Striking Temperature Effect on the Enantioselectivity, a Minimal Amino Alcohol Loading, and an Efficient Recycling of the Amino Alcohol

Catalytic asymmetric addition of diphenylzinc to cyclic α,β-unsaturated ketones

Synthesis and Characterization of Some New C2 Symmetric Chiral Bisamide Ligands Derived from Chiral Feist’s Acid

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