Highly Enantioselective Diethylzinc Addition to Imines Employing Readily Available <i>N</i>-Monosubstituted Amino Alcohols

Zhang, Hai-Le; Zhang, Xiaomei; Gong, Liu‐Zhu; Mi, Aiqiao; Cui, Xin; Jiang, Yaozhong; Choi, Michael C. K.; Chan, Albert S. C.

doi:10.1021/ol025728u

Cited by 35 publications

(7 citation statements)

References 37 publications

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“…Analogous to the work of the Soai group, a large library of 1,2-amino-alcohols, as well as oxazolines, has been examined by Gong, Mi, and coworkers ( Figure 3). 56,57,58,59 While the authors identified ligands 95, 96, and 97 as those which afforded the highest yields and enantioselectivities in these studies, these compounds offer only modest improvements over the previous ligands (vide supra).…”

Section: Scheme 36mentioning

confidence: 97%

N-Phosphinoylimines: An Emerging Class of Reactive Intermediates for Stereoselective Organic Synthesis

Weinreb¹,

Orr²

2005

Synthesis

114

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N-Phosphinoylimines have recently begun to attract significant attention from synthetic chemists for the preparation of nitrogen-containing molecules. Several methods have been developed for the synthesis, or in situ generation, of these reactive electrophilic species. N-Phosphinoylimines undergo a wide range of reactions, including nucleophilic additions and cycloadditions. These imines are also effective electrophiles in a number of diastereoselective and enantioselective reactions. An advantage of using N-phosphinoylimines is that the reaction products can be easily deprotected under mild acidic conditions, leading to amines. This review outlines the preparation and uses of N-phosphinoylimines with particular emphasis on their applications in stereoselective processes.

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Section: Scheme 36mentioning

confidence: 97%

N-Phosphinoylimines: An Emerging Class of Reactive Intermediates for Stereoselective Organic Synthesis

Weinreb¹,

Orr²

2005

Synthesis

114

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“…This has been a limitation not only in diorganozinc addition chemistry (20)(21)(22)(23)(24)(25), but also in catalytic asymmetric nitro-Mannich (26), Mannich (27), and Strecker (28) processes that use similar electrophilic precursors. This inherent limitation is also present in the preparation of N-acylimines, and several strategies have been developed to circumvent this problem.…”

mentioning

confidence: 99%

Catalytic asymmetric addition of diorganozinc reagents to N -phosphinoylalkylimines

Côté

Boezio

Charette

2004

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

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The synthesis of ␣-chiral amines bearing two alkyl groups has been hampered by the accessibility and stability of the alkylimine precursor. Herein, we report an efficient strategy to generate the alkyl-substituted imine in situ that is compatible with the MeDuPHOS monoxide⅐Cu(I) catalyzed addition of diorganozinc reagents. The sulfinic acid adduct of the imine is readily prepared by mixing diphenylphosphinic amide, the aldehyde, and sulfinic acid. The sulfinic acid adduct is generally isolated by filtration. The addition of diorganozinc reagents in the presence of Me-DuPHOS monoxide⅐Cu(I) and the in situ-generated imines affords the corresponding ␣-chiral amines in high yields and enantiomeric excesses.

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“…It had been reported that N ‐monosubstituted amino alcohols exhibited slightly higher enantioselectivities than their N , N ‐disubstituted congener 4b. c Although 1 was successfully employed for the addition of dialkylzinc to imines with high enantioselectivity, we surveyed the N ‐monosubstituted amino alcohols 2 a–i for the feasibility of promoting the enantioselective addition reaction.…”

Section: Resultsmentioning

confidence: 99%

Enantioselective Addition of Dialkylzinc to Aromatic Aldimines Mediated by Camphor‐Derived Chiral β‐Amino Alcohols

Huang

Uang

2014

Chemistry An Asian Journal

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The enantioselective addition of diethylzinc or dimethylzinc to N-(diphenylphosphinoyl)imines mediated by 1 or 2 could be achieved in high yields (70-97 %) and enantioselectivities (85-98 % ee). The catalytic loading of 1 or 2 a could be reduced to 10 mol % for methylation or ethylation of imines in high yields and enantioselectivities (79-96 %) when the reaction was conducted in the presence of 1.8 equiv of methanol. N-Monosubstituted amino alcohols induced higher enantioselectivity than their N,N-disubstituted congener in our catalytic system.

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Highly Enantioselective Diethylzinc Addition to Imines Employing Readily Available N-Monosubstituted Amino Alcohols

Cited by 35 publications

References 37 publications

N-Phosphinoylimines: An Emerging Class of Reactive Intermediates for Stereoselective Organic Synthesis

N-Phosphinoylimines: An Emerging Class of Reactive Intermediates for Stereoselective Organic Synthesis

Catalytic asymmetric addition of diorganozinc reagents to N -phosphinoylalkylimines

Enantioselective Addition of Dialkylzinc to Aromatic Aldimines Mediated by Camphor‐Derived Chiral β‐Amino Alcohols

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