Enantioselective Organocatalytic Cyclopropanation via Ammonium Ylides

Papageorgiou, Charles D.; Dios, Maria A. Cubillo de; Ley, Steven V.; Gaunt, Matthew J.

doi:10.1002/anie.200460234

Cited by 265 publications

(86 citation statements)

References 22 publications

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“…Based upon all observations, a mechanism for the reaction has been proposed (Scheme 2) involving tertiary amine catalysis and quaternary amine enolate formation which has previously been described, for example, in cyclopropanation reactions. [12] Scheme 2. Proposed mechanism of the formation of 2 using MOPS.…”

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confidence: 99%

The First Mimetic of the Transketolase Reaction

et al. 2006

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Although the biocatalytic formation of acyclic α,α′‐dihydroxy ketones by transketolase is well documented in the literature, there is currently no one‐pot chemical synthesis of these dihydroxy ketones available. Here, we report preliminary results of an atom‐efficient one‐pot synthesis of α,α′‐dihydroxy ketones in water by a mimic of the transketolase reaction. The formation of a quaternary ammonium enolate is postulated in this tertiary‐amine‐mediated carbon–carbon bond‐forming reaction. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)

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confidence: 99%

The First Mimetic of the Transketolase Reaction

et al. 2006

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“…Chemical shifts are given in d relative to tetramethylsilane (TMS), the coupling constants J are given in Hz. The spectra were recorded in CDCl 3 as solvent at room temperature, TMS served as internal standard (d = 0 ppm) for 1 H NMR spectroscopy, and CDCl 3 was used as internal standard (d = 77.0 ppm) for 13 C NMR spectroscopy. HPLC was carried out with a Waters 2690 Millennium instrument with a photodiode array detector.…”

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

“…[11] Aggarwal, [12] Gaunt, [13] and MacMillan [14] and their co-workers have pioneered the development of enantioselective cyclopropanations of a,b-unsaturated ketones, amides, esters, nitriles, sulfones, and aldehydes by using either preformed or in situ generated ylides. [12][13][14] Connon and co-workers have also reported the employment of Cinchona alkaloid derivatives as catalysts for the asymmetric cyclopropanation of nitroalkenes. [15] Inspired by these investigations and our previous experience in organocatalytic cascade catalysis, [16] we envisioned a simple asymmetric entry to 2-formyl cyclopropanes by chiral-amine-mediated domino reactions between halomalonates or 2-halo-b-ketoesters and a,b-unsaturated aldehydes (Scheme 1).…”

Section: Introductionmentioning

confidence: 99%

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One‐Pot Organocatalytic Domino Michael/α‐Alkylation Reactions: Direct Catalytic Enantioselective Cyclopropanation and Cyclopentanation Reactions

Ibrahem

Zhao

Rios

et al. 2008

Chemistry A European J

155

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The development of one-pot organocatalytic domino Michael/alpha-alkylation reactions between bromomalonates or bromoacetoacetate esters and alpha,beta-unsaturated aldehydes is presented. The chiral-amine-catalyzed reactions with bromomalonates as substrates give access to the corresponding 2-formylcyclopropane derivatives in high yields with excellent diastereoselectivity and up to 99 % ee. The catalytic domino Michael/alpha-alkylation reactions between 4-bromo-acetoacetate and enals provide a route for the synthesis of functionalized cyclopentanones in good to high yields with 93-99 % ee. The products from the organocatalytic reactions were also reduced with high diastereoselectivity to the corresponding cyclopropanols and cyclopentanols, respectively. Moreover, one-pot combinations of amine and heterocyclic carbene catalysis (AHCC) enabled the highly enantioselective synthesis of beta-malonate esters (91-97 % ee) from the reaction between bromomalonates and enals. The tandem catalysis included the catalytic domino reaction followed by catalytic in situ chemoselective ring-opening of the 2-formylcyclopropane intermediates.

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“…On this basis, by using a chiral catalyst which has similar structure to DABCO [20] the chiral three-membered carbocyclic compounds could be synthesized, which is great significance for synthesis of complex molecules and drugs.…”

Section: Application Of Dabco In Building Three-membered Carbocyclic mentioning

confidence: 99%

Organic reactions catalyzed by 1, 4-diazabicyclo [2.2.2] octane (DABCO)

Yang

Tian

2008

Front. Chem. China

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The organic reactions catalyzed by 1, 4-diazabicyclo [2.2.2] octane (DABCO) are reviewed. Most of the reactions start conveniently from available substrate and proceed under mild conditions. The reactions are environmentally friendly and the catalyst can be recycled in some cases. The perspectives on DABCO-catalyzed reactions are pointed out. Keywords 1, 4-diazabicyclo [2.2.2] octane (DABCO), organic synthesis, catalysis 1,4-Diazabicyclo [2.2.2] octane (DABCO, Scheme 1), a cage-like compound, is a small diazabicyclic molecule, which has weak alkalescence, medium-hindrance and widely used in organic synthesis reactions. On the one hand, it can serve as a weak base and ligand, for example, reactions of the Nmethylation of indoles and Pd(OAc) 2 /DABCO-catalyzed Stille cross-coupling reaction, etc. On the other hand, it is also a very widely used catalyst in organic synthesis reactions, for example, the Baylis-Hillman reaction, synthesis of three-membered carbocyclic compounds and heterocyclic reactions containing oxygen, nitrogen. According to the types of products, this paper introduces the application of DABCO in organic synthesis in the recent years.

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Enantioselective Organocatalytic Cyclopropanation via Ammonium Ylides

Cited by 265 publications

References 22 publications

The First Mimetic of the Transketolase Reaction

The First Mimetic of the Transketolase Reaction

One‐Pot Organocatalytic Domino Michael/α‐Alkylation Reactions: Direct Catalytic Enantioselective Cyclopropanation and Cyclopentanation Reactions

Organic reactions catalyzed by 1, 4-diazabicyclo [2.2.2] octane (DABCO)

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