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Sayuri Kobayashi - One of the best experts on this subject based on the ideXlab platform.
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swern oxidation of bicyclo 2 2 1 hept 5 ene 2 3 diol and its pyrazine fused derivatives an improved synthesis of bicyclo 2 2 1 hept 5 ene 2 3 dione and an unexpected ring opening reaction
Molecules, 2000Co-Authors: Tomoshige Kobayashi, Sayuri KobayashiAbstract:Abstract: An improved synthesis of bicyclo[2.2.1]hept-5-ene-2,3-dione by Swern oxidation ofbicyclo[2.2.1]hept-5-ene-2,3-diol, and an unexpected ring-opening reaction by the Swern oxida-tion of pyrazine-fused congeners are described. Keywords: Swern oxidation, vicinal cis -diol, α-diketone, ring-opening, Norbornene, pyrazine. Introduction Bicyclo[2.2.1]heptane skeletons have been a useful building block for the construction of molecular archi-tectures with a concavity [1]. In the course of our studies to synthesize a host molecule utilizing a negativeelectrostatic potential filed of pyrazine rings, a general method to prepare norobornene-2,3-dione and its py-razine-fused derivatives was required. We describe here an improved synthesis of bicyclo[2.2.1]hept-5-ene-2,3-dione ( 3 ) by Swern oxidation of bicyclo[2.2.1]hept-5-ene-2,3-diol ( 6 ). We also report that a similarSwern oxidation reaction of pyrazine-fused congeners 10 and 11 was found to undergo an unexpected rring-opening reaction.
Robert A Batey - One of the best experts on this subject based on the ideXlab platform.
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lewis acid catalyzed three component hetero diels alder povarov reaction of n arylimines with strained Norbornene derived dienophiles
ChemInform, 2010Co-Authors: Chris D Smith, Julia Gavrilyuk, Alan J Lough, Robert A BateyAbstract:Generally, the hetero-Diels−Alder reaction (Povarov reaction) of N-arylimine dienes are limited to reaction with activated, electron-rich alkenes. However, introduction of ring strain in the dienophile, as with moderately strained bicyclo[2.2.1]heptenes (Norbornene), enables three-component Povarov reaction with in situ formed N-arylimines under Lewis acid catalyzed conditions (BF3·OEt2). The reactions proceed efficiently with a diverse set of commercially available anilines and benzaldehydes, as well as a variety of substituted Norbornenes. The corresponding tetrahydroquinolines are formed with high complexity in a multicomponent fashion and are obtained in good yield and high diastereoselectivity. In addition, more reactive ethyl glyoxylate derived imines were utilized to achieve faster, room temperature reactions with Norbornene. In all cases, attack of the N-arylimine dienes occurred exclusively from the exo-face of the Norbornene ring, but the relative stereochemistry of the substituent α to the tetr...
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lewis acid catalyzed three component hetero diels alder povarov reaction of n arylimines with strained Norbornene derived dienophiles
Journal of Organic Chemistry, 2010Co-Authors: Chris D Smith, Julia Gavrilyuk, Alan J Lough, Robert A BateyAbstract:Generally, the hetero-Diels−Alder reaction (Povarov reaction) of N-arylimine dienes are limited to reaction with activated, electron-rich alkenes. However, introduction of ring strain in the dienophile, as with moderately strained bicyclo[2.2.1]heptenes (Norbornene), enables three-component Povarov reaction with in situ formed N-arylimines under Lewis acid catalyzed conditions (BF3·OEt2). The reactions proceed efficiently with a diverse set of commercially available anilines and benzaldehydes, as well as a variety of substituted Norbornenes. The corresponding tetrahydroquinolines are formed with high complexity in a multicomponent fashion and are obtained in good yield and high diastereoselectivity. In addition, more reactive ethyl glyoxylate derived imines were utilized to achieve faster, room temperature reactions with Norbornene. In all cases, attack of the N-arylimine dienes occurred exclusively from the exo-face of the Norbornene ring, but the relative stereochemistry of the substituent α to the tetr...
Tomoshige Kobayashi - One of the best experts on this subject based on the ideXlab platform.
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swern oxidation of bicyclo 2 2 1 hept 5 ene 2 3 diol and its pyrazine fused derivatives an improved synthesis of bicyclo 2 2 1 hept 5 ene 2 3 dione and an unexpected ring opening reaction
Molecules, 2000Co-Authors: Tomoshige Kobayashi, Sayuri KobayashiAbstract:Abstract: An improved synthesis of bicyclo[2.2.1]hept-5-ene-2,3-dione by Swern oxidation ofbicyclo[2.2.1]hept-5-ene-2,3-diol, and an unexpected ring-opening reaction by the Swern oxida-tion of pyrazine-fused congeners are described. Keywords: Swern oxidation, vicinal cis -diol, α-diketone, ring-opening, Norbornene, pyrazine. Introduction Bicyclo[2.2.1]heptane skeletons have been a useful building block for the construction of molecular archi-tectures with a concavity [1]. In the course of our studies to synthesize a host molecule utilizing a negativeelectrostatic potential filed of pyrazine rings, a general method to prepare norobornene-2,3-dione and its py-razine-fused derivatives was required. We describe here an improved synthesis of bicyclo[2.2.1]hept-5-ene-2,3-dione ( 3 ) by Swern oxidation of bicyclo[2.2.1]hept-5-ene-2,3-diol ( 6 ). We also report that a similarSwern oxidation reaction of pyrazine-fused congeners 10 and 11 was found to undergo an unexpected rring-opening reaction.
Chris D Smith - One of the best experts on this subject based on the ideXlab platform.
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lewis acid catalyzed three component hetero diels alder povarov reaction of n arylimines with strained Norbornene derived dienophiles
ChemInform, 2010Co-Authors: Chris D Smith, Julia Gavrilyuk, Alan J Lough, Robert A BateyAbstract:Generally, the hetero-Diels−Alder reaction (Povarov reaction) of N-arylimine dienes are limited to reaction with activated, electron-rich alkenes. However, introduction of ring strain in the dienophile, as with moderately strained bicyclo[2.2.1]heptenes (Norbornene), enables three-component Povarov reaction with in situ formed N-arylimines under Lewis acid catalyzed conditions (BF3·OEt2). The reactions proceed efficiently with a diverse set of commercially available anilines and benzaldehydes, as well as a variety of substituted Norbornenes. The corresponding tetrahydroquinolines are formed with high complexity in a multicomponent fashion and are obtained in good yield and high diastereoselectivity. In addition, more reactive ethyl glyoxylate derived imines were utilized to achieve faster, room temperature reactions with Norbornene. In all cases, attack of the N-arylimine dienes occurred exclusively from the exo-face of the Norbornene ring, but the relative stereochemistry of the substituent α to the tetr...
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lewis acid catalyzed three component hetero diels alder povarov reaction of n arylimines with strained Norbornene derived dienophiles
Journal of Organic Chemistry, 2010Co-Authors: Chris D Smith, Julia Gavrilyuk, Alan J Lough, Robert A BateyAbstract:Generally, the hetero-Diels−Alder reaction (Povarov reaction) of N-arylimine dienes are limited to reaction with activated, electron-rich alkenes. However, introduction of ring strain in the dienophile, as with moderately strained bicyclo[2.2.1]heptenes (Norbornene), enables three-component Povarov reaction with in situ formed N-arylimines under Lewis acid catalyzed conditions (BF3·OEt2). The reactions proceed efficiently with a diverse set of commercially available anilines and benzaldehydes, as well as a variety of substituted Norbornenes. The corresponding tetrahydroquinolines are formed with high complexity in a multicomponent fashion and are obtained in good yield and high diastereoselectivity. In addition, more reactive ethyl glyoxylate derived imines were utilized to achieve faster, room temperature reactions with Norbornene. In all cases, attack of the N-arylimine dienes occurred exclusively from the exo-face of the Norbornene ring, but the relative stereochemistry of the substituent α to the tetr...
Julia Gavrilyuk - One of the best experts on this subject based on the ideXlab platform.
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lewis acid catalyzed three component hetero diels alder povarov reaction of n arylimines with strained Norbornene derived dienophiles
ChemInform, 2010Co-Authors: Chris D Smith, Julia Gavrilyuk, Alan J Lough, Robert A BateyAbstract:Generally, the hetero-Diels−Alder reaction (Povarov reaction) of N-arylimine dienes are limited to reaction with activated, electron-rich alkenes. However, introduction of ring strain in the dienophile, as with moderately strained bicyclo[2.2.1]heptenes (Norbornene), enables three-component Povarov reaction with in situ formed N-arylimines under Lewis acid catalyzed conditions (BF3·OEt2). The reactions proceed efficiently with a diverse set of commercially available anilines and benzaldehydes, as well as a variety of substituted Norbornenes. The corresponding tetrahydroquinolines are formed with high complexity in a multicomponent fashion and are obtained in good yield and high diastereoselectivity. In addition, more reactive ethyl glyoxylate derived imines were utilized to achieve faster, room temperature reactions with Norbornene. In all cases, attack of the N-arylimine dienes occurred exclusively from the exo-face of the Norbornene ring, but the relative stereochemistry of the substituent α to the tetr...
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lewis acid catalyzed three component hetero diels alder povarov reaction of n arylimines with strained Norbornene derived dienophiles
Journal of Organic Chemistry, 2010Co-Authors: Chris D Smith, Julia Gavrilyuk, Alan J Lough, Robert A BateyAbstract:Generally, the hetero-Diels−Alder reaction (Povarov reaction) of N-arylimine dienes are limited to reaction with activated, electron-rich alkenes. However, introduction of ring strain in the dienophile, as with moderately strained bicyclo[2.2.1]heptenes (Norbornene), enables three-component Povarov reaction with in situ formed N-arylimines under Lewis acid catalyzed conditions (BF3·OEt2). The reactions proceed efficiently with a diverse set of commercially available anilines and benzaldehydes, as well as a variety of substituted Norbornenes. The corresponding tetrahydroquinolines are formed with high complexity in a multicomponent fashion and are obtained in good yield and high diastereoselectivity. In addition, more reactive ethyl glyoxylate derived imines were utilized to achieve faster, room temperature reactions with Norbornene. In all cases, attack of the N-arylimine dienes occurred exclusively from the exo-face of the Norbornene ring, but the relative stereochemistry of the substituent α to the tetr...
