Evaluating β-amino acids as enantioselective organocatalysts of the Hajos–Parrish–Eder–Sauer–Wiechert reaction

Davies, Stephen G.; Russell, Angela J.; Sheppard, Ruth L.; Smith, Andrew D.; Thomson, James E.

doi:10.1039/b711171a

Cited by 68 publications

(21 citation statements)

References 68 publications

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“…13 C NMR (100 MHz, CDCl 3 ): δ = 216.4, 198.1, 169.7, 123.9, 111.0, 48.7, 35.8, 32.9, 29.2, 26.8, 20.5 ppm. Spectral data are in agreement with literature values 16…”

Section: Methodssupporting

confidence: 90%

“…(+)‐( S )‐Hajos–Parrish dione 4 was prepared according to literature procedures 16. The enantioselective conjugate reduction/Al enolate trapping reaction17 was attempted with DMPU in place of HMPA; however, none of the desired adduct 3 was observed (Scheme ), and we were forced to revise our retrosynthetic analysis.…”

Section: Resultsmentioning

confidence: 99%

“…Hajos‐Parrish Dione 4: The dione 4 was prepared according to a literature procedure,16 from 2‐methyl‐cyclopentane‐1,3‐dione (1.00 g, 8.92 mmol), methyl vinyl ketone (0.87 mL, 10.7 mmol), and L ‐proline (0.26 g, 2.27 mmol), to afford 4 (0.99 g, 68 % over 2 steps) as a pale orange solid. M.p.…”

Section: Methodsmentioning

confidence: 99%

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Synthesis of DOHNAA, a Mycobacterium tuberculosis Cholesterol CD Ring Catabolite and FadD3 Substrate

et al. 2015

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DOHNAA (2) is a key catabolite in the Mycobacterium tuberculosis (Mtb) cholesterol degradation pathway. The CoA ester of 2 has been implicated in regulation of gene transcription that is ultimately responsible for degradation of the C and D rings of cholesterol. A synthetic route to 2 is reported here, by a key DMSO‐mediated Morita–Bayliss–Hillman‐type alkylation of the Hajos–Parrish dione. As DOHNAA has to date only been available from microbial sources in very small quantities, the synthesis described will enable further studies of the enzymes involved in cholesterol degradation in Mtb and facilitate ongoing structure–activity studies based on this compound scaffold.

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“…13 C NMR (100 MHz, CDCl 3 ): δ = 216.4, 198.1, 169.7, 123.9, 111.0, 48.7, 35.8, 32.9, 29.2, 26.8, 20.5 ppm. Spectral data are in agreement with literature values 16…”

Section: Methodssupporting

confidence: 90%

Section: Resultsmentioning

confidence: 99%

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Synthesis of DOHNAA, a Mycobacterium tuberculosis Cholesterol CD Ring Catabolite and FadD3 Substrate

et al. 2015

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“…In an effort to obtain enantioselective intramolecular aldolization, Shibasaki and coworkers reported the formation of 6 in 52 % ee and 60 % yield (THF, ‐52 °C, 6 d) in the presence of catalytic amounts of an ytterbium dialkoxide originally prepared from ( R , R )‐tartaric acid. Davies and coworkers investigated the asymmetric synthesis of 6 from 1 in the presence of (1′ R ,2′ S )‐5‐(2′‐aminocyclopentan‐1′‐yl) tetrazole as a catalyst; however, the product obtained in 67 % yield was racemic. Mahrwald and coworkers tested a tetranuclear BINOL–titanium catalyst to give racemic 6 in 44 % yield.…”

Section: Resultsmentioning

confidence: 99%

Metal Coordination Controlled and Bifunctional H‐Bonded Catalysis in Stereoselective Intramolecular Aldol Cyclizations toward Carbocyclic Tertiary β‐Ketols

2017

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The principle of bifunctional catalysis is shown in the highly regio‐ and stereoselective intramolecular aldolization of 2‐methyl‐1,3‐cyclopentanedione, C2‐substituted with a methyl ethyl ketone group, to provide [3.2.1]‐bicyclooctanol diones in the presence of catalytic amounts of either LiBr and 1,8‐diazabicyclo[5.4.0]undec‐7‐ene (DBU), or 1,5,7‐triazabicyclo[4.4.0]dec‐5‐ene (TBD). Mechanistic investigations corroborated by DFT calculations show that LiBr engages in a bifunctional coordination of two carbonyl moieties and leads to the preorganization of the reactive enolate intermediate for a base‐mediated intramolecular aldol cyclization. On the other hand, TBD catalysis of the triketone substrate proceeds through a bifunctional H‐bonded mechanism to give the same aldol product as the major diastereomer. The LiBr and TBD‐catalyzed highly stereocontrolled intramolecular aldol cyclizations can be extended to other di‐ and triketones to give carbocyclic and carbobicyclic products as single diastereomers.

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“…[23] The most frequently used access towards a-cyano acrylic acids is provided by the Knoevenagel condensation, which employs an excess of pyridine or piperidine with heating.…”

Section: Resultsmentioning

confidence: 99%

Combined Transition‐Metal‐ and Organocatalysis: An Atom Economic C3 Homologation of Alkenes to Carbonyl and Carboxylic Compounds

Kemme

Šmejkal

Breit

2010

Chemistry A European J

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A combination of regioselective room-temperature/ambient-pressure hydroformylation (transition-metal catalysis) and decarboxylative Knoevenagel reactions (organocatalysis) allowed for the development of an efficient, one-pot C3 homologation of terminal alkenes to (E)-alpha,beta-unsaturated acids and esters, (E)-beta,gamma-unsaturated acids, (E)-alpha-cyano acrylic acids, and alpha,beta-unsaturated nitriles. All reactions proceed under mild conditions, tolerate a variety of functional groups, and furnish unsaturated carbonyl compounds in good yields and with excellent regio- and stereocontrol. Further, an iterative C2 homologation of (E)-alpha,beta-unsaturated carboxylic acids is possible through a combination of decarboxylative hydroformylation employing a supramolecular catalyst followed by decarboxylative Knoevenagel condensation with an organocatalyst.

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Evaluating β-amino acids as enantioselective organocatalysts of the Hajos–Parrish–Eder–Sauer–Wiechert reaction

Cited by 68 publications

References 68 publications

Synthesis of DOHNAA, a Mycobacterium tuberculosis Cholesterol CD Ring Catabolite and FadD3 Substrate

Synthesis of DOHNAA, a Mycobacterium tuberculosis Cholesterol CD Ring Catabolite and FadD3 Substrate

Metal Coordination Controlled and Bifunctional H‐Bonded Catalysis in Stereoselective Intramolecular Aldol Cyclizations toward Carbocyclic Tertiary β‐Ketols

Combined Transition‐Metal‐ and Organocatalysis: An Atom Economic C3 Homologation of Alkenes to Carbonyl and Carboxylic Compounds

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