François Trécourt - Academia.edu (original) (raw)
Papers by François Trécourt
Journal of Organic Chemistry, Aug 31, 2004
The ability of the 2-pyridyl and 1-isoquinolyl groups to direct metalation was studied in the ben... more The ability of the 2-pyridyl and 1-isoquinolyl groups to direct metalation was studied in the benzene series. For this purpose, 2-(halophenyl)pyridines and 1-(halophenyl)isoquinolines were prepared. Interestingly, nucleophilic addition reactions on the azine ring were not observed under kinetic control using butyllithium, and the substrates were cleanly deprotonated on the benzene ring: the azine ring acidifies the adjacent hydrogen H2' (N-H2' interaction through space and/or inductive electron-withdrawing effect) and probably favors the approach of butyllithium (chelation). Under thermodynamic conditions using lithium dialkylamides, the presence of the azine group makes the lithio derivative at C2' more stable (chelation and/or inductive electron-withdrawing effect). This was evidenced in two ways: (1) syntheses of 2-halophenyllithiums (F, Cl, Br) substituted at C6 by a 2-pyridyl or 1-isoquinolyl group without elimination of lithium halide and (2) iodine migration from C2' to C4' when treating 2-(3-halo-2-iodophenyl)pyridines or 1-(3-fluoro-2-iodophenyl)isoquinoline with LTMP. Comparisons between the 2-pyridyl and fluoro units showed the latter was the stronger directing group for deprotonation.
Tetrahedron, Aug 1, 2002
Deprotonation of all isomeric lithium pyridinecarboxylates and subsequent trapping with hexachlor... more Deprotonation of all isomeric lithium pyridinecarboxylates and subsequent trapping with hexachloroethane or iodine afforded straightforward access to chloro- and iodopyridinecarboxylic acids, respectively. Starting from lithium 5-bromonicotinate, the introduction of an iodine atom at C4 and further halogen migration allowed the potential of this method to be extended to the synthesis of more elaborate derivatives.
ChemInform, Aug 12, 2010
Synthesis of 11H-Pyrido(2,3-a)carbazoles and 6H-Pyrido(3,2-b) carbazoles from 8-Methoxy Bromoquin... more Synthesis of 11H-Pyrido(2,3-a)carbazoles and 6H-Pyrido(3,2-b) carbazoles from 8-Methoxy Bromoquinolines.-An efficient route to the title compounds is developed starting from quinoline and benzene building blocks. The products may be of interest as synthons for DNA intercaling drugs.
Organic and Biomolecular Chemistry, 2003
2-(2- and 3-Pyridyl)anilines (1, 2), 2,2-dimethyl-N-[2-(2- and 3-pyridyl)phenyl]propanamides (3, ... more 2-(2- and 3-Pyridyl)anilines (1, 2), 2,2-dimethyl-N-[2-(2- and 3-pyridyl)phenyl]propanamides (3, 4), and 2-, 3- and 4-(2-methoxyphenyl)pyridines (7-9) are readily synthesized using cross-coupling reactions. Whereas the amines 1, 2 undergo side reactions, the corresponding amides 3, 4 are deprotonated with lithium 2,2,6,6-tetramethylpiperidide (LTMP): the compound 3 at C6' under in situ quenching, and the compound 4 at C4'. When the ether 7 is subjected to the same reagent, lithiation occurs at C6'.
Tetrahedron, Oct 1, 2003
Quinoline derivatives Quinoline derivatives R 0410 Synthesis and Reactivity of Lithium Tri(quinol... more Quinoline derivatives Quinoline derivatives R 0410 Synthesis and Reactivity of Lithium Tri(quinolinyl)magnesates.-2-, 3-, and 4-Bromoquinolines are converted into the corresponding title magnesates by treatment with Bu 3 MgLi, prepared in situ by mixing BuMgCl and BuLi in a 1:2 ratio. These intermediates are quenched with various electrophiles or involved in palladium-catalyzed coupling reactions with heteroaryl halides to afford functionalized quinolines. The reaction conditions can be also applied to 3-bromopyridine and phenyl bromide in place of the quinolyl bromides.-(DUMOUCHEL, S.; MONGIN*, F.;
Journal of Organic Chemistry, Apr 8, 1998
Caerulomycins produced by Streptomyces caeruleus, and collismycins more recently isolated from St... more Caerulomycins produced by Streptomyces caeruleus, and collismycins more recently isolated from Streptomyces species, are bipyridinic molecules endowed with antibiotic and cytotoxic activities. The first syntheses of caerulomycin E (1), as well as new syntheses of caerulomycin A (2), are reported. Methodologies involving efficiently controlled reactions such as metalation and crosscoupling reactions have been developed from 2,2′-bipyridine. The functionalization at C-6 could be achieved by metalation of 2,2′-bipyridine N-oxides 5 and 12. 6-Halo-4-methoxy-2,2′-bipyridines (6, 10, 11) became key-molecules of these different pathways, and further functionalization at C-5 allowed the first syntheses of collismycins A (3) and C (4).
Tetrahedron, May 1, 2002
ÐThe palladium-catalyzed cross-coupling reactions between arylmagnesium halides (phenylmagnesium ... more ÐThe palladium-catalyzed cross-coupling reactions between arylmagnesium halides (phenylmagnesium chloride, mesitylmagnesium bromide, 4-(methoxycarbonyl)phenylmagnesium chloride and 4-cyanophenylmagnesium chloride) and halopyridines allowed the synthesis of substituted pyridines. Owing to the remarkably mild conditions used (often below 08C), the reaction could be extended to the use of functionalized halopyridines, haloquinolines and halodiazines.
ChemInform, Sep 27, 1988
Lithiation of 2‐methoxypyridine (I) with methyllithium (II) is catalyzed by diisopropylamine to p... more Lithiation of 2‐methoxypyridine (I) with methyllithium (II) is catalyzed by diisopropylamine to proceed regioselectively at position 3, yielding the lithio derivative (III).
ChemInform, Aug 16, 2010
First Synthesis of (±)-Harzianopyridone by Metalation of Polysubstituted O-Pyridylcarbamates.-The... more First Synthesis of (±)-Harzianopyridone by Metalation of Polysubstituted O-Pyridylcarbamates.-The key step of the first synthesis of (±)-harzianopyridone (VII), an antifungal metabolite of Trichoderma harzianum, is the metalation of the polysubstituted O-pyridylcarbamate (IIa) to introduce the side chain at C-5. This strategy allows to synthesize a large number of analogues.
ChemInform, Aug 5, 2010
First Synthesis of Caerulomycin C.-Caerulomycin C (VIII), an antibiotic produced by Streptomyces ... more First Synthesis of Caerulomycin C.-Caerulomycin C (VIII), an antibiotic produced by Streptomyces caeruleus, is synthesized in 5 steps starting from (I) with an overall yield of 11%.-(TRECOURT, F.; GERVAIS, B.;
Journal of Organic Chemistry, 1996
Tetrahedron Letters, Nov 1, 2005
Furan was deprotonated on treatment with 1/3 equiv of Bu 3 MgLi in THF at rt. The lithium arylmag... more Furan was deprotonated on treatment with 1/3 equiv of Bu 3 MgLi in THF at rt. The lithium arylmagnesate formed was either trapped with electrophiles or involved in a palladium-catalyzed cross-coupling reaction with 2-bromopyridine. The highly coordinated magnesate Bu 4 MgLi 2 (1/3 equiv) proved to be a better deprotonating agent than Bu 3 MgLi; the monitoring of the reaction using NMR spectroscopy showed that the deprotonation of furan at rt required 2 h whereas the subsequent electrophilic trapping was instantaneous. The method was extended to benzofuran, allowing its functionalization at C2 in high yields. The deprotonation of 2-methylfuran and lithium furfurylalkoxide at C5 turned out to be difficult, requiring either long reaction times or higher temperatures.
Tetrahedron, 1993
Key wof& Alkalokls; Alkoxypyri~; coup-Mualation; ortllino. Abrb.cd:Anewtotalsynthesisiativestqwof... more Key wof& Alkalokls; Alkoxypyri~; coup-Mualation; ortllino. Abrb.cd:Anewtotalsynthesisiativestqwofthealkrloid~ir~~metbodologyiwolvcrmeblrtion of mUhoxypyridhd to afford 2.halo-3,4dimcthoxy+diy~ridine on which an homoan~ling don is pdbrmtd to build the 2,2'-bipyridyl shdurc of the alkaloid. Orelline (1) is one the main three substances preacnt in the poisonous mushroom Cortinarius OreJJamts. Its structure has been elucidated by Antkowiak and Gessner.1 In the previous syntheses, described by Dehmlow and Schulz 2 (8 steps , 1.4 % yield), Tiecco et al. 3 (8 steps, 4.4 % yield) and Hasseberg and Gerlach 4 (5 steps, 4.8 % yield) , the 2,2'-bipyridyl structure was obtained by an homocoupling reaction on 2-halo pyridine derivatives (the halogen being introduced by direct halogenation). We tried to introduce the halogen at C2 by a regioselective metalation 5 of a 3,4_disubstituted pyridine. The 3,4diiethoxypyridine (2) key molecule 6 was prepared by an original met&ion of 4-methoxypyridine (3).7 The total yield of the synthesis of Orelline (1) +JM so improved.(scheme 1) 1 scheme 1 Discussion Section Our laboratory team know-how in the metal&ion field 3 allowed us to investigate a new synthesis of Orelline (1) using this reaction on substituted pyridmes. The retrosynthetic scheme 1 shows that 3,4-dimethoxy
ChemInform, Aug 17, 2010
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was e... more ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Chemischer Informationsdienst, Jul 10, 1979
Journal of Organic Chemistry, Aug 31, 2004
The ability of the 2-pyridyl and 1-isoquinolyl groups to direct metalation was studied in the ben... more The ability of the 2-pyridyl and 1-isoquinolyl groups to direct metalation was studied in the benzene series. For this purpose, 2-(halophenyl)pyridines and 1-(halophenyl)isoquinolines were prepared. Interestingly, nucleophilic addition reactions on the azine ring were not observed under kinetic control using butyllithium, and the substrates were cleanly deprotonated on the benzene ring: the azine ring acidifies the adjacent hydrogen H2' (N-H2' interaction through space and/or inductive electron-withdrawing effect) and probably favors the approach of butyllithium (chelation). Under thermodynamic conditions using lithium dialkylamides, the presence of the azine group makes the lithio derivative at C2' more stable (chelation and/or inductive electron-withdrawing effect). This was evidenced in two ways: (1) syntheses of 2-halophenyllithiums (F, Cl, Br) substituted at C6 by a 2-pyridyl or 1-isoquinolyl group without elimination of lithium halide and (2) iodine migration from C2' to C4' when treating 2-(3-halo-2-iodophenyl)pyridines or 1-(3-fluoro-2-iodophenyl)isoquinoline with LTMP. Comparisons between the 2-pyridyl and fluoro units showed the latter was the stronger directing group for deprotonation.
Tetrahedron, Aug 1, 2002
Deprotonation of all isomeric lithium pyridinecarboxylates and subsequent trapping with hexachlor... more Deprotonation of all isomeric lithium pyridinecarboxylates and subsequent trapping with hexachloroethane or iodine afforded straightforward access to chloro- and iodopyridinecarboxylic acids, respectively. Starting from lithium 5-bromonicotinate, the introduction of an iodine atom at C4 and further halogen migration allowed the potential of this method to be extended to the synthesis of more elaborate derivatives.
ChemInform, Aug 12, 2010
Synthesis of 11H-Pyrido(2,3-a)carbazoles and 6H-Pyrido(3,2-b) carbazoles from 8-Methoxy Bromoquin... more Synthesis of 11H-Pyrido(2,3-a)carbazoles and 6H-Pyrido(3,2-b) carbazoles from 8-Methoxy Bromoquinolines.-An efficient route to the title compounds is developed starting from quinoline and benzene building blocks. The products may be of interest as synthons for DNA intercaling drugs.
Organic and Biomolecular Chemistry, 2003
2-(2- and 3-Pyridyl)anilines (1, 2), 2,2-dimethyl-N-[2-(2- and 3-pyridyl)phenyl]propanamides (3, ... more 2-(2- and 3-Pyridyl)anilines (1, 2), 2,2-dimethyl-N-[2-(2- and 3-pyridyl)phenyl]propanamides (3, 4), and 2-, 3- and 4-(2-methoxyphenyl)pyridines (7-9) are readily synthesized using cross-coupling reactions. Whereas the amines 1, 2 undergo side reactions, the corresponding amides 3, 4 are deprotonated with lithium 2,2,6,6-tetramethylpiperidide (LTMP): the compound 3 at C6' under in situ quenching, and the compound 4 at C4'. When the ether 7 is subjected to the same reagent, lithiation occurs at C6'.
Tetrahedron, Oct 1, 2003
Quinoline derivatives Quinoline derivatives R 0410 Synthesis and Reactivity of Lithium Tri(quinol... more Quinoline derivatives Quinoline derivatives R 0410 Synthesis and Reactivity of Lithium Tri(quinolinyl)magnesates.-2-, 3-, and 4-Bromoquinolines are converted into the corresponding title magnesates by treatment with Bu 3 MgLi, prepared in situ by mixing BuMgCl and BuLi in a 1:2 ratio. These intermediates are quenched with various electrophiles or involved in palladium-catalyzed coupling reactions with heteroaryl halides to afford functionalized quinolines. The reaction conditions can be also applied to 3-bromopyridine and phenyl bromide in place of the quinolyl bromides.-(DUMOUCHEL, S.; MONGIN*, F.;
Journal of Organic Chemistry, Apr 8, 1998
Caerulomycins produced by Streptomyces caeruleus, and collismycins more recently isolated from St... more Caerulomycins produced by Streptomyces caeruleus, and collismycins more recently isolated from Streptomyces species, are bipyridinic molecules endowed with antibiotic and cytotoxic activities. The first syntheses of caerulomycin E (1), as well as new syntheses of caerulomycin A (2), are reported. Methodologies involving efficiently controlled reactions such as metalation and crosscoupling reactions have been developed from 2,2′-bipyridine. The functionalization at C-6 could be achieved by metalation of 2,2′-bipyridine N-oxides 5 and 12. 6-Halo-4-methoxy-2,2′-bipyridines (6, 10, 11) became key-molecules of these different pathways, and further functionalization at C-5 allowed the first syntheses of collismycins A (3) and C (4).
Tetrahedron, May 1, 2002
ÐThe palladium-catalyzed cross-coupling reactions between arylmagnesium halides (phenylmagnesium ... more ÐThe palladium-catalyzed cross-coupling reactions between arylmagnesium halides (phenylmagnesium chloride, mesitylmagnesium bromide, 4-(methoxycarbonyl)phenylmagnesium chloride and 4-cyanophenylmagnesium chloride) and halopyridines allowed the synthesis of substituted pyridines. Owing to the remarkably mild conditions used (often below 08C), the reaction could be extended to the use of functionalized halopyridines, haloquinolines and halodiazines.
ChemInform, Sep 27, 1988
Lithiation of 2‐methoxypyridine (I) with methyllithium (II) is catalyzed by diisopropylamine to p... more Lithiation of 2‐methoxypyridine (I) with methyllithium (II) is catalyzed by diisopropylamine to proceed regioselectively at position 3, yielding the lithio derivative (III).
ChemInform, Aug 16, 2010
First Synthesis of (±)-Harzianopyridone by Metalation of Polysubstituted O-Pyridylcarbamates.-The... more First Synthesis of (±)-Harzianopyridone by Metalation of Polysubstituted O-Pyridylcarbamates.-The key step of the first synthesis of (±)-harzianopyridone (VII), an antifungal metabolite of Trichoderma harzianum, is the metalation of the polysubstituted O-pyridylcarbamate (IIa) to introduce the side chain at C-5. This strategy allows to synthesize a large number of analogues.
ChemInform, Aug 5, 2010
First Synthesis of Caerulomycin C.-Caerulomycin C (VIII), an antibiotic produced by Streptomyces ... more First Synthesis of Caerulomycin C.-Caerulomycin C (VIII), an antibiotic produced by Streptomyces caeruleus, is synthesized in 5 steps starting from (I) with an overall yield of 11%.-(TRECOURT, F.; GERVAIS, B.;
Journal of Organic Chemistry, 1996
Tetrahedron Letters, Nov 1, 2005
Furan was deprotonated on treatment with 1/3 equiv of Bu 3 MgLi in THF at rt. The lithium arylmag... more Furan was deprotonated on treatment with 1/3 equiv of Bu 3 MgLi in THF at rt. The lithium arylmagnesate formed was either trapped with electrophiles or involved in a palladium-catalyzed cross-coupling reaction with 2-bromopyridine. The highly coordinated magnesate Bu 4 MgLi 2 (1/3 equiv) proved to be a better deprotonating agent than Bu 3 MgLi; the monitoring of the reaction using NMR spectroscopy showed that the deprotonation of furan at rt required 2 h whereas the subsequent electrophilic trapping was instantaneous. The method was extended to benzofuran, allowing its functionalization at C2 in high yields. The deprotonation of 2-methylfuran and lithium furfurylalkoxide at C5 turned out to be difficult, requiring either long reaction times or higher temperatures.
Tetrahedron, 1993
Key wof& Alkalokls; Alkoxypyri~; coup-Mualation; ortllino. Abrb.cd:Anewtotalsynthesisiativestqwof... more Key wof& Alkalokls; Alkoxypyri~; coup-Mualation; ortllino. Abrb.cd:Anewtotalsynthesisiativestqwofthealkrloid~ir~~metbodologyiwolvcrmeblrtion of mUhoxypyridhd to afford 2.halo-3,4dimcthoxy+diy~ridine on which an homoan~ling don is pdbrmtd to build the 2,2'-bipyridyl shdurc of the alkaloid. Orelline (1) is one the main three substances preacnt in the poisonous mushroom Cortinarius OreJJamts. Its structure has been elucidated by Antkowiak and Gessner.1 In the previous syntheses, described by Dehmlow and Schulz 2 (8 steps , 1.4 % yield), Tiecco et al. 3 (8 steps, 4.4 % yield) and Hasseberg and Gerlach 4 (5 steps, 4.8 % yield) , the 2,2'-bipyridyl structure was obtained by an homocoupling reaction on 2-halo pyridine derivatives (the halogen being introduced by direct halogenation). We tried to introduce the halogen at C2 by a regioselective metalation 5 of a 3,4_disubstituted pyridine. The 3,4diiethoxypyridine (2) key molecule 6 was prepared by an original met&ion of 4-methoxypyridine (3).7 The total yield of the synthesis of Orelline (1) +JM so improved.(scheme 1) 1 scheme 1 Discussion Section Our laboratory team know-how in the metal&ion field 3 allowed us to investigate a new synthesis of Orelline (1) using this reaction on substituted pyridmes. The retrosynthetic scheme 1 shows that 3,4-dimethoxy
ChemInform, Aug 17, 2010
ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was e... more ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Chemischer Informationsdienst, Jul 10, 1979