Stereoselective synthesis of methyl (Z)-α-methoxyacrylates via two-carbon homologation of aldehydes

Baati, Rachid; Mioskowski, Charles; Kashinath, Dhurke; Kodepelly, Sanjeevarao; Lu, Biao; Falck, John R.

doi:10.1016/j.tetlet.2008.11.027

Cited by 13 publications

(5 citation statements)

References 27 publications

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“…IR (film) 2953, 2835, 1728, 1634, 1607, 1510, 1369, 1296, 1242, 1177, 1146, 1032, 951, 833, 845, 783, 621 cm –1 ; 1 H NMR (400 MHz, CDCl 3 ) 7.17 (d, J = 8.21 Hz, 2H), 6.84 (d, J = 9.00 Hz, 2H), 6.12 (s, 1H), 3.81 (s, 3H), 3.75 (s, 3H), 3.72 (s, 3H); 13 C{1H} NMR (100 MHz, CDCl 3 ) δ 164.6, 158.6, 146.4, 129.8, 126.7, 113.5, 109.9, 56.0, 55.2, 52.1; HRMS (ESI) m / z : [M + Na] + Calcd for C 12 H 14 O 4 Na + 245.0784; Found 245.0781. Data for compound ( Z )- 8d : TLC (10% EtOAc in hexanes) R f : 0.44 (UV/CAM); spectral data for compound ( Z )- 8d are in agreement with published data. , …”

Section: Methodssupporting

confidence: 85%

A Nonoxidative Sequence for the Preparation of 1,2-Diketone Derivatives Using Aldehyde and Organometallic Building Blocks

2022

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This study investigates a synthetic sequence for the preparation of 1,2-diketone products. The sequence avoids oxidative conditions and instead employs reliable transformations including the Horner−Wadsworth−Emmons and addition of Grignard reagents to N-methyl-N-methoxy (Weinreb) amide intermediates. The reaction sequence is suitable for the synthesis of nonsymmetric aliphatic and aryl substituted derivatives.1,2-Dicarbonyl derivatives, including α-ketoacids, -esters, and -amides as well as 1,2-diketones, are widely found in nature and have recognized biological activities. 1−7 Additionally, 1,2dicarbonyl substrates serve as versatile precursors that are commonly used in the preparation of valuable intermediates and downstream products. For example, recent advances in modern organic photochemistry have exploited α-ketoacids as precursors for carbonyl radical species 8,9 and 1,2-dicarbonyl substrates remain central to classic condensation strategies for the construction of aromatic heterocycles including imidazoles, 10−13 pyrazines, 14,15 1,2,4-triazines, 16 quinoxalines, 17,18 and other 1,4-diazine derivatives. 19

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Section: Methodssupporting

confidence: 85%

A Nonoxidative Sequence for the Preparation of 1,2-Diketone Derivatives Using Aldehyde and Organometallic Building Blocks

2022

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“…The Cr–Cl distances of terminal chlorides of 1 (2.366–2.396 Å) were longer than those of 2 , because the geometry around Cr of monomer part of 1 was roughly square planar, and the trans effect exerted by TMEDA affected it more directly. Although other gem -di(dichlorochromio)methane complexes having silyl, iodo, and boryl functionalities on the bridged methine carbons, stabilized with various ligands, including pyridine, bipyridine, and PPh 3 , could be synthesized in a similar procedure, all attempts to obtain suitable crystals for single-crystal X-ray crystallographic analysis by recrystallization failed. These results may imply that the bulky trimethylsilyl group effectively stabilized the unstable gem -dichromiomethane species, which was advantageous for isolation and structural characterization by X-ray crystallography.…”

Section: Resultsmentioning

confidence: 99%

“…Recently, CrCl 2 was also shown act as a useful catalyst for cross-coupling of aryl halides with Grignard reagents by Knochel and co-workers . Another traditional but unique use of chromium reagents is in the alkylidenation of aldehydes. , Takai reported that the use of organochromium reagents prepared from CrCl 2 and di- or trihalomethanes (RCHX 2 ) converted aldehydes into functionalized alkenes in good yields (Scheme a) . The reaction proceeded under mild conditions with excellent stereoselectivity and functional group compatibility to provide synthetically useful alkenyl iodides, silanes, and boranes.…”

Section: Introductionmentioning

confidence: 99%

Structural Characterization and Unique Catalytic Performance of Silyl-Group-Substituted Geminal Dichromiomethane Complexes Stabilized with a Diamine Ligand

et al. 2017

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Stabilization by a silyl group on the methylene carbon and a diamine ligand led to the isolation of gem-dichromiomethane species. X-ray crystallography confirmed the identity of the structure of this rare example of reactive gem-dimetalloalkane species. The isolated gem-dichromiomethane complex acted as a storable silylmethylidene carbene equivalent, with reactivity that could be changed dramatically upon addition of a Lewis acid (ZnCl) and a base (TMEDA) to promote both silylalkylidenation of polar aldehydes and silylcyclopropanation of nonpolar alkenes. Identification of a key reactive species also identified the catalytic version of these transformations and provided insights into the reaction mechanism. In contrast to Simmons-Smith cyclopropanation, the real reactive species for the current cyclopropanation was a chromiocarbene species, not a chromium carbenoid species.

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“…The first one reported by Kitazume, involved a domino reaction between the sodium salt of dimethyl fluoromalonate and Michael acceptors. The second, developed by Mioskowski and Falck, is based on the reaction of ethyl trifluoroacetate with aldehydes using a Cr(II)-mediated olefination sequence. Our group recently developed an efficient synthesis of α-fluoroacrylates via a diethylzinc-promoted Wittig reaction .…”

Section: Introductionmentioning

confidence: 99%

Diethylzinc-Mediated One-Step Stereoselective Synthesis of α-Fluoroacrylates from Aldehydes and Ketones. Two Different Pathways Depending on the Carbonyl Partner

et al. 2009

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A efficient methodology allowing the one-pot stereoselective synthesis of alpha-fluoroacrylates, based on the addition of ethyl dibromofluoroacetate to a carbonyl derivative using diethylzinc as organometallic mediator, is described. Two different pathways have been identified depending on the involved carbonyl partner. In the case of aldehydes, an E2-type mechanism has been identified, whereas ketones go through an E1cb-type mechanism.

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Stereoselective synthesis of methyl (Z)-α-methoxyacrylates via two-carbon homologation of aldehydes

Cited by 13 publications

References 27 publications

A Nonoxidative Sequence for the Preparation of 1,2-Diketone Derivatives Using Aldehyde and Organometallic Building Blocks

A Nonoxidative Sequence for the Preparation of 1,2-Diketone Derivatives Using Aldehyde and Organometallic Building Blocks

Structural Characterization and Unique Catalytic Performance of Silyl-Group-Substituted Geminal Dichromiomethane Complexes Stabilized with a Diamine Ligand

Diethylzinc-Mediated One-Step Stereoselective Synthesis of α-Fluoroacrylates from Aldehydes and Ketones. Two Different Pathways Depending on the Carbonyl Partner

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