Catalytic asymmetric alkylation of ketones using organometallic reagents

Madduri, Ashoka V. R.; Harutyunyan, Syuzanna R.; Minnaard, Adriaan J.

doi:10.1016/j.ddtec.2012.10.010

Cited by 17 publications

(9 citation statements)

References 52 publications

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“…[15][16][17][18][19][20][21][22][23] However, despite these intriguing features, catalytic stereoselective synthesis of chiral tertiary alcohols with vicinal stereocenters from racemic -branched ketones remains a challenge (Scheme 1b). [24][25][26] This is possibly because the -substituent on the ketone substrate can interfere with the recognition of the ketones by the catalyst, which hinders the reaction development. As supporting evidence, in contrast to the success of the synthesis of tertiary alcohols from achiral ketones, [24][25][26] no successful catalytic asymmetric C-C bond-forming reactions of racemic -branched ketones to construct vicinal stereocenters are available to date, apart from dynamic kinetic reductive amination 27 and hydrogenation reactions.…”

Section: Introductionmentioning

confidence: 99%

“…[24][25][26] This is possibly because the -substituent on the ketone substrate can interfere with the recognition of the ketones by the catalyst, which hinders the reaction development. As supporting evidence, in contrast to the success of the synthesis of tertiary alcohols from achiral ketones, [24][25][26] no successful catalytic asymmetric C-C bond-forming reactions of racemic -branched ketones to construct vicinal stereocenters are available to date, apart from dynamic kinetic reductive amination 27 and hydrogenation reactions. [28][29][30] To exploit the desired process, we speculated that the chiral catalyst should be flexible to overcome the influence of the -substituent of the racemic ketones and recognize one enantiomer selectively to form a "matched" catalystketone complex.…”

Section: Introductionmentioning

confidence: 99%

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Constructing Tertiary Alcohols with Vicinal Stereocenters: Highly Diastereo- and Enantioselective Cyanosilylation of α-Branched Acyclic Ketones and Their Kinetic Resolution

et al. 2022

CCS Chem

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We report the first highly diastereo-and enantioselective C-C bond-forming reaction of racemic -branched ketones to construct tertiary alcohols with adjacent stereocenters. Accordingly, a highly stereoselective cyanosilylation of racemic ketones is developed using our bifunctional cyanating reagent, Me 2 (CH 2 Cl)SiCN, giving C  -tetrasubstituted silyl cyanohydrins with two vicinal stereocenters in up to >20:1 d.r. and 90-98% e.e. values, which can undergo various diversification reactions by taking advantage of the chloromethyl group. A highly selective kinetic resolution of acyclic -branched ketones is also developed that allows facile access to acyclic -alkyl, allyl, and propargyl ketones with good recovery and excellent e.e. values. The synthetic value of this protocol is further demonstrated by the formal synthesis of the antiobesity agent, taranabant (MK-0364).The activation of Jacobsen's privileged catalyst (salen)AlCl by a suitable phosphorane plays a crucial role in the reaction. X-ray analysis of single crystals of phosphorane-(salen)AlCl complexes and theoretical calculations help provide a working model. The present transformation opens a new direction for the catalytic

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Constructing Tertiary Alcohols with Vicinal Stereocenters: Highly Diastereo- and Enantioselective Cyanosilylation of α-Branched Acyclic Ketones and Their Kinetic Resolution

et al. 2022

CCS Chem

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“…Much research has focused on the use of dialkylzinc reagents in the alkylation of aldehydes, while the alkylation of ketones is more challenging and often a Ti‐ or Al‐containing activator is used in the addition of diorganozinc compounds to a ketone . Due to the possible formation of Zn‐enolate compounds from α‐acidic ketones or the formation of self‐aldol products, the addition of organozinc compounds to ketones is often not successful .…”

Section: Introductionmentioning

confidence: 99%

1,2‐Addition of Diethylzinc to a Bis(Imidazolyl)ketone Ligand

et al. 2018

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In this study, the selective 1,2‐addition of diethylzinc to the ketone functionality of BMdiPhIK [bis(1‐methyl‐4,5‐diphenylimidazolyl)ketone] is shown. The reaction product is isolated in a dimeric form with a planar Zn2(µ‐O)2‐motif keeping the two monomers together. This compound can serve as a model for reactive intermediates in the catalytic alkylation of ketones with diorganozinc reagents. Hydrolysis of this binuclear zinc compound leads to isolation of the C‐alkylated product in 89 % yield. A reaction pathway is proposed in which BMdiPhIK initially coordinates to diethylzinc as a bidentate bis(nitrogen) ligand. This is followed by the homolytic cleavage of the Zn–Et bond and in‐cage recombination of the Et‐radical and the Zn‐coordinated ligand‐centered radical, which is mainly localized on the carbonyl moiety of the ligand.

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“…They are very important in organic chemistry due to their wide use in pharmaceuticals and appearance in natural products. The main way to produce them is the asymmetric synthesis from ketones by the addition of organometallic complexes derived from Zn, Al, Mg and Li [310].…”

Section: Potential Existing Technologies and New Considerations For Vmentioning

confidence: 99%

Utilization of Volatile Organic Compounds as an Alternative for Destructive Abatement

et al. 2015

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Abstract:The treatment of volatile organic compounds (VOC) emissions is a necessity of today. The catalytic treatment has already proven to be environmentally and economically sound technology for the total oxidation of the VOCs. However, in certain cases, it may also become economical to utilize these emissions in some profitable way. Currently, the most common way to utilize the VOC emissions is their use in energy production. However, interesting possibilities are arising from the usage of VOCs in hydrogen and syngas production. Production of chemicals from VOC emissions is still mainly at the research stage. However, few commercial examples exist. This review will summarize the commercially existing VOC utilization possibilities, present the utilization applications that are in the research stage and introduce some novel ideas related to the catalytic utilization possibilities of the VOC emissions. In general, there exist a vast number of possibilities for VOC OPEN ACCESSCatalysts 2015, 5 1093 utilization via different catalytic processes, which creates also a good research potential for the future.

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Catalytic asymmetric alkylation of ketones using organometallic reagents

Cited by 17 publications

References 52 publications

Constructing Tertiary Alcohols with Vicinal Stereocenters: Highly Diastereo- and Enantioselective Cyanosilylation of α-Branched Acyclic Ketones and Their Kinetic Resolution

Constructing Tertiary Alcohols with Vicinal Stereocenters: Highly Diastereo- and Enantioselective Cyanosilylation of α-Branched Acyclic Ketones and Their Kinetic Resolution

1,2‐Addition of Diethylzinc to a Bis(Imidazolyl)ketone Ligand

Utilization of Volatile Organic Compounds as an Alternative for Destructive Abatement

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