Catalyzed metalation applied to 2-methoxypyridine

Trécourt, François; Mallet, M.; Marsais, Francis; Quéguiner, G.

doi:10.1021/jo00242a005

Cited by 63 publications

(37 citation statements)

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“…Mongin recently reported a correlation between the regioselectivities observed for the metallation of a wide range of substituted pyridines and their computed C−H acidities, revealing that judicious choice of the organometallic reagent and the reaction conditions are key to control selectivity . Thus, several mono‐ and bimetallic systems have been reported that can execute the metallation of pyridines under certain reaction conditions (typically at low temperature) . In most cases, metallation products are isolated after quenching with an electrophile, with little structural information on the organometallic intermediates involved in these processes.…”

Section: Introductionmentioning

confidence: 99%

Structural and Synthetic Insights into Pyridine Homocouplings Mediated by a β‐Diketiminato Magnesium Amide Complex

Davin

Clegg

Kennedy

et al. 2018

Chemistry A European J

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The reaction of [( Nacnac)Mg(TMP)] (1) with 4-subtituted pyridines proceeds via sequential regioselective metallation and 1,2-addition to furnish a range of symmetric 4,4'-R -2,2'-bipyridines in good yield, representing a new entry into bipyridine synthesis. Interestingly, the reaction of 1 with 2-OMe-pyridine led to formation of asymmetric bipyridine 6, resulting from the C6-magnesiation of the heterocycle followed by a C-C coupling step by addition to the C2 position of a second, non-metallated molecule, and subsequent elimination of [ NacnacMgOMe] (7). Synthesis combined with spectroscopic and structural analysis help rationalise the underlying processes resulting in the observed reactivity, and elucidate the key role that the sterically encumbered β-diketiminate ligand plays in determining regioselectivity.

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Section: Introductionmentioning

confidence: 99%

Structural and Synthetic Insights into Pyridine Homocouplings Mediated by a β‐Diketiminato Magnesium Amide Complex

Davin

Clegg

Kennedy

et al. 2018

Chemistry A European J

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“…As only very low yields of 5-bromobenzo[c]-2.7-naphthyridine (21) could be obtained, we decided to continue with 5-cblorobenzo[c]-2,7-napbthyridine (20) as the coupling partner for 3-trimethylstannyl-2pyridinecarboxaldehyde (19). We had some hopes about this reaction as we had previously managed to We therefore sought to find other conditions which could manage to execute this coupling.…”

Section: Resultsmentioning

confidence: 99%

Synthesis of Various Substituted Benzo[c]-2,7-naphthyridines and an Approach towards the Skeleton of Meridine. Considerations about the Effect of Copper(II) Oxide

Björk¹,

Malm²,

Hörnfeldt³

et al. 1997

HETEROCYCLES

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Derivatives of benm[c]-2.7-naphthyridines have been prepared in good yields andin one step through the use of the Pd(0)-catalyzed cross couplings of Cfonnyl-and bacetyl-3-pyridyluimethylstannanes with onho-bromoacetanilides. Perlolidine, an alkaloids present in perennial rye grass, was readily prepared in a few steps taking advantage of the cross coupling.An approach towards the pentacyclic ring skeleton of meridine has also been made, leading to several new derivatives of benza[c]-2.7-naphthyridine. All cross couplings are greatly promoted by the addition of staichiometric amounts of copper(I1) oxide and a comparison with the use of other catalytic systems in the Pd(0)-catalyzed cross couplings is made.In connection with our work on the effects of the mode of annelation on physical properties and reactivities of tricyclic heterocyclic systems with the phenanthrene annelation pattern, we have previously described convenient one-pot procedures involving Pd(0)-catalyzed cross couplings for the synthesis of phe- nanthrene, thieno[b,c]quinolines and isoquinolines, dithieno[b,d]pyridines and thieno[b,c]naphthyridines(for reviews cf. refs.',2). While preparing the 24 isomers of the thieno[b and c]-fused naphthyridines we experienced problems withStille type reactions. We therefore introduced the concept of using a co-reagent, in an attempt to raise the yields in these reactions. Silver(1) oxide was the first co-reagent used and good results were obtained both regarding the reaction rate and the yield when applied to low yielding sluggish reactions. 3.4 The usefulness of silver(1) oxide as co-reagent has also been shown by other group^.^,^ As the yields of the thieno[bl-fused naphthyridines7 still were low, a large amount of other additives were tested whereby copper(I1) oxide was found to be an even better ~o -r e a g e n t .~-'~

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“…A utilização de grupos ortodiretores oxigenados permitiu a sín-tese rápida e eficaz da azaxantona 65 e da 8-azacumarina 66 52 (Esquema 29). Uma outra ilustração da utilidade destes grupos ortodiretores foi apresentada pela primeira síntese realizada por Quéguiner e colaboradores 53 da caerulomicina C 67 (Esquema 30), um antibiótico isolado em 1959 54 cuja estrutura foi somente elucidada em 1977 55 .…”

Section: Aplicações Sintéticasunclassified

Reações de ortometalacão em piridinas

Souza¹,

Almeida²

2002

Quím. Nova

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Recebido em 29/11/00; aceito em 2/5/01 THE ORTHO METALATION REACTION IN PYRIDINES. In this paper we describe a powerful methodology for the regiospecific construction of polysubstituted aromatic and heteroaromatic compounds. The DoM reaction (direct ortho-metalation) comprises the deprotonation in position ortho of a aromatic or heteroaromatic containing DMG (directed metalation group) by strong bases, normally an alkyllithium reagent, leading to an ortho-lithiated species. These species, upon treatment with electrophilic reagents, gives 1,2 disubstituted products.

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Catalyzed metalation applied to 2-methoxypyridine

Cited by 63 publications

References 0 publications

Structural and Synthetic Insights into Pyridine Homocouplings Mediated by a β‐Diketiminato Magnesium Amide Complex

Structural and Synthetic Insights into Pyridine Homocouplings Mediated by a β‐Diketiminato Magnesium Amide Complex

Synthesis of Various Substituted Benzo[c]-2,7-naphthyridines and an Approach towards the Skeleton of Meridine. Considerations about the Effect of Copper(II) Oxide

Reações de ortometalacão em piridinas

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