Synthesis of Chiral Diazine and Pyridine Sulfoxides. Asymmetric Induction by Chiral Sulfoxides in an “Aromatic <i>O</i><i>rtho</i>-Directed Metalation−Reaction with Electrophiles Sequence”. Diazines. 24

Pollet, Paméla; Turck, Alain; Plé, Nelly; Quéguiner, G.

doi:10.1021/jo981125d

Cited by 31 publications

(16 citation statements)

References 38 publications

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“…59 The remarkable diastereoselectivity observed is explained by the approach of the aldehyde on the less-hindered convex face of the metalated pyridazine leading to the formation of the S C ,R S diastereoisomer (Scheme 28). …”

Section: -Inductionmentioning

confidence: 99%

Recent developments in chiral non-racemic sulfinyl group chemistry in asymmetric synthesis

Hanquet¹,

Colobert²,

Lanners³

et al. 2003

Arkivoc

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Chiral sulfinyl groups have been widely used in organic synthesis as a stereo-and enantiodirecting functionality and the high efficiency of the selectivity has received much attention in recent years. In this review we wish to cover the work published in the literature since 1996. The participation of a chiral sulfinyl function in a wide range of reactions as well as the application of these methodologies to the synthesis of natural products are reported.

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Section: -Inductionmentioning

confidence: 99%

Recent developments in chiral non-racemic sulfinyl group chemistry in asymmetric synthesis

Hanquet¹,

Colobert²,

Lanners³

et al. 2003

Arkivoc

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“…Finally, the remaining challenge is probably the asymmetric metallation. Some tracks were discovered by Comins in the nicotinic series (see above), Quéguiner [118] with chiral pyridine sulfoxides, Maddaluno [119] with chiral amides, or Fort [120] in the ionic chiral environment (ICE) concept induced by chiral lithium aminoalkoxides (Figure 15.10) while these approaches were recently applied with TMP-zincates [121].…”

Section: Discussionmentioning

confidence: 99%

Lithiated Aza‐Heterocycles in Modern Synthesis

Fort

Comoy

2014

Lithium Compounds in Organic Synthesis

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Introduction Functional nitrogen-containing heteroaromatic compounds, especially sixmembered ones (pyridines, diazines, quinolines, and their fused derivatives), have attracted the attention of chemists worldwide because they play an important role in the development of new pharmaceuticals [1], agrochemicals [2], catalysts [3], or materials [4] (including polymers).Besides the classical reactions (i.e., electrophilic heteroaromatic substitutions on heterocycles or single electron-transfer (SET) mediated reactions with brominated derivatives) [5] and ex nihilo ring syntheses [6], metallation reactions providing organolithium compounds are of particular interest because they allow the direct functionalization starting from bare or sparsely substituted heterocycles intrinsically more acidic than similar benzene-ring systems. However, the strong bases used for metallation as well as the prepared organolithiums also exhibit a large propensity for nucleophilic addition. Further, though numerous methods have been described for the single derivatization, multiple functionalization often appears much more sensitive and difficult because of the complexation or aggregation phenomena observed either with primary substituents or with the nitrogen atom in the heterocycle itself. These complex phenomena, together with the variation in reaction conditions (temperature, solvent, ratio), produce various competitive reaction pathways. Thus, an arsenal of methodologies has then been developed to tune the regio-, chemio-, and sometimes stereoselectivities. The goal is generally to control these additional influences, providing variation of kinetic or thermodynamic acidity at various sites susceptible to lithiation.With a special focus on pyridines, quinolines, diazines, and fused pyridinic compounds, this chapter describes organolithium tools that allow (i) direct derivatization of bare N-containing heteroaromatics; (ii) metallation of dipolar adducts of pyridines and analogs; (iii) halogen/Li exchanges; (iv) ring metallation by using directing metallation groups; (v) lithiation invoking an halogen dance; and (vi) lateral and remote lithiations (Scheme 15.1). Next, the usefulness of these tools, often Lithium Compounds in Organic Synthesis: From Fundamentals to Applications, First Edition. Edited by Renzo Luisi and Vito Capriati.

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“…These by-products can often be avoided by using very short lithiation times or by in situ trapping with a compatible electrophile (Scheme 19.177) [195]. Queguiner and coworkers [196] have reported the ortho-lithiation of pyridazine with subsequent trapping with chiral sulfinate esters, affording chiral sulfoxides 167 with high enantiomeric excesses (% ee) (Scheme 19.178). These sulfoxide adducts can then be subjected to a second ortho-lithiation-electrophile trapping sequence with aldehydes to provide fully-substituted pyridazines 168 with high diastereoselectivities (% de).…”

Section: Reactions Of Metallated Pyridazinesmentioning

confidence: 99%

“…Similarly, lithiation of 5-bromopyrimidine and reaction with enantiomericallypure chiral sulfinate esters gives chiral sulfoxides 171 with high enantioselectivities (Scheme 19.183) [196]. Ortho-metalation of 2,6-dichloropyrazine 172 with lithium 2,2,6,6-tetramethylpiperidide (LTMP) followed by quenching with a lactone produces the C-heteroaryl glycoside 173 (Scheme 19.185) [194].…”

Section: Reactions Of Metallated Pyridazinesmentioning

confidence: 99%

Six‐Membered Heterocycles: 1,2‐, 1,3‐, and 1,4‐Diazines and Related Systems

Cabal

2011

Modern Heterocyclic Chemistry

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Synthesis of Chiral Diazine and Pyridine Sulfoxides. Asymmetric Induction by Chiral Sulfoxides in an “Aromatic Ortho-Directed Metalation−Reaction with Electrophiles Sequence”. Diazines. 24

Cited by 31 publications

References 38 publications

Recent developments in chiral non-racemic sulfinyl group chemistry in asymmetric synthesis

Recent developments in chiral non-racemic sulfinyl group chemistry in asymmetric synthesis

Lithiated Aza‐Heterocycles in Modern Synthesis

Six‐Membered Heterocycles: 1,2‐, 1,3‐, and 1,4‐Diazines and Related Systems

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