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Andrew Sutherland - One of the best experts on this subject based on the ideXlab platform.
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A stereoselective synthesis of (+)-physoperuvine using a tandem Aza-Claisen Rearrangement and ring closing metathesis reaction.
Organic & biomolecular chemistry, 2009Co-Authors: Ahmed M. Zaed, Michael D. Swift, Andrew SutherlandAbstract:A stereoselective synthesis of (+)-physoperuvine, a tropane alkaloid from Physalis peruviana Linne has been developed using a one-pot tandem Aza-Claisen Rearrangement and ring closing metathesis reaction to form the key amino-substituted cycloheptene ring.
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Tandem Aza-Claisen Rearrangement and ring-closing metathesis reactions: the stereoselective synthesis of functionalised carbocyclic amides
Tetrahedron Letters, 2009Co-Authors: Michael D. Swift, Adele Donaldson, Andrew SutherlandAbstract:A one-pot, tandem process has been developed for the efficient synthesis of functionalised carbocyclic amides. A substituted cyclopentenyl trichloroacetamide was synthesised using a tandem thermal Aza-Claisen Rearrangement and RCM process, while an analogous cyclohexenyl trichloroacetamide was generated with high diastereoselectivity using a tandem MOM-ether directed metal-catalysed Aza-Claisen Rearrangement and RCM process.
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A tandem Aza-Claisen Rearrangement and ring closing metathesis reaction for the synthesis of cyclic allylic trichloroacetamides.
Organic letters, 2007Co-Authors: Michael D. Swift, Andrew SutherlandAbstract:A one-pot tandem palladium(II)-catalyzed Aza-Claisen Rearrangement and ring closing metathesis process has been developed for the efficient synthesis of cyclic allylic trichloroacetamides. The use of chiral Pd(II) catalysts such as (S)-COP−Cl during the Rearrangement stage results in the preparation of these compounds in excellent yields and in high enantiomeric excess.
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ether directed stereoselective aza claisen Rearrangements synthesis of the piperidine alkaloid α conhydrine
Organic Letters, 2007Co-Authors: Andrew G Jamieson, Andrew SutherlandAbstract:A new approach for the stereoselective synthesis of the piperidine alkaloid (+)-α-conhydrine and its pyrrolidine derivative has been developed using a palladium(II)-catalyzed, MOM-ether-directed Aza-Claisen Rearrangement and ring-closing metathesis to effect the key steps.
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A stereoselective synthesis of (2R,3S)-2-amino-3,4-dihydroxybutyric acid using an ether directed Aza-Claisen Rearrangement
Tetrahedron Letters, 2007Co-Authors: Michael D. Swift, Andrew SutherlandAbstract:A new approach for the stereoselective synthesis of (2R,3S)-2-amino-3,4-dihydroxybutyric acid, an α-amino acid from Lyophyllum ulmarium, has been accomplished using an ether directed Aza-Claisen Rearrangement. On investigation of optimal conditions for this key step it was shown for the first time that Au(I) can be used to catalyse this transformation.
Young-ger Suh - One of the best experts on this subject based on the ideXlab platform.
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Advances in Aza‐Claisen‐Rearrangement‐Induced Ring‐Expansion Strategies
Asian Journal of Organic Chemistry, 2017Co-Authors: Jong-wha Jung, Seok-ho Kim, Young-ger SuhAbstract:The Aza-Claisen Rearrangement, also known as the 3-aza-Cope Rearrangement, has attracted significant attention because it can be used as a complimentary method to access a diverse range of useful organic molecules. The presence of a nitrogen atom at the 3-position enables the tethering of various-sized azacycles, thereby giving ring-expansion strategies that take advantage of the Aza-Claisen Rearrangement a distinct advantage compared to other [3,3]-sigmatropic Rearrangements. Recent advances in Aza-Claisen Rearrangements have facilitated otherwise-inaccessible ring expansions in a highly stereoselective manner. The utility of Aza-Claisen-Rearrangement-induced ring-expansion strategies has been exemplified in the synthesis of a diverse range of natural products. This Focus Review summarizes recent advances in Aza-Claisen-Rearrangement-induced ring-expansion strategy, in particular applications in the synthesis of bioactive alkaloids.
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Construction of the Azacyclic Core of Tabernaemontanine-Related Alkaloids via Tandem Reformatsky-Aza-Claisen Rearrangement.
The Journal of organic chemistry, 2017Co-Authors: Young-ger Suh, Jaehoon Sim, Changjin Lim, Jae Kyun Lee, Young-joon Surh, Seung-mann PaekAbstract:A divergent synthetic methodology for a tabernaemontanine-related alkaloid was developed. The synthetic route features practical improvements in the Pictet–Spengler cyclization for the tetrahydro-β-carboline intermediate and an unprecedented tandem Reformatsky–Aza-Claisen Rearrangement to create the core carbon skeleton and stereochemistries of tabernaemontanine-related alkaloids.
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Construction of the Azacyclic Core of Tabernaemontanine-Related Alkaloids via Tandem Reformatsky–Aza-Claisen Rearrangement
2017Co-Authors: Young-ger Suh, Jaehoon Sim, Changjin Lim, Jae Kyun Lee, Young-joon Surh, Seung-mann PaekAbstract:A divergent synthetic methodology for a tabernaemontanine-related alkaloid was developed. The synthetic route features practical improvements in the Pictet–Spengler cyclization for the tetrahydro-β-carboline intermediate and an unprecedented tandem Reformatsky–Aza-Claisen Rearrangement to create the core carbon skeleton and stereochemistries of tabernaemontanine-related alkaloids
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Studies on the Aza‐Claisen Rearrangement of 7‐ to 9‐Membered Vinylazacycles.
ChemInform, 2016Co-Authors: Jong-wha Jung, Seok-ho Kim, Young-ger Suh, Jae-kyung Jung, Jaebong Jang, Wonil Lee, Seon-mi Kim, Jaehoon SimAbstract:The amide enolate-induced Aza-Claisen Rearrangement of the vinylazacycles furnishes 11- to 13-membered macrolactams with an internal (E)-olefinic bond, not accessible by conventional methods.
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Asymmetric formal synthesis of schulzeines A and C.
Organic & biomolecular chemistry, 2012Co-Authors: Jaebong Jang, Jong-wha Jung, Jaehoon Sim, Jaeseung Ahn, Dong-jo Chang, Dae-duk Kim, Young-ger SuhAbstract:The asymmetric formal synthesis of schulzeines A and C is described. Key features of the synthesis include the efficient and stereoselective construction of the benzoquinolizidine skeleton via the Aza-Claisen Rearrangement-induced ring expansion of the 1-vinyl-N-glycyl-isoquinoline, which was prepared by the highly enantioselective asymmetric allylation of the 8-benzyloxy-substituted dihydroisoquinoline and by the acid-catalyzed transannulation of the resulting 10-membered lactam.
Tetsuto Tsunoda - One of the best experts on this subject based on the ideXlab platform.
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Construction of an asymmetric quaternary carbon via an asymmetric Aza-Claisen Rearrangement and its application in the total synthesis of (+)-α-cuparenone
Tetrahedron: Asymmetry, 2012Co-Authors: Takeshi Nishii, Makoto Inai, Hiroto Kaku, Mitsuyo Horikawa, Fumiaki Miyamae, Makoto Yoshizuka, Tetsuto TsunodaAbstract:Abstract Excess lithium hexamethyldisilazide (LHMDS) with LiCl prompted the asymmetric Aza-Claisen Rearrangement of carboxamide and retarded the decomposition of its amide enolate. The addition of these two reagents was a key step that led to the total synthesis of (+)-α-cuparenone with a stereogenic quaternary center.
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Total Synthesis of (+)-BrefeldinC Utilizing Aza-Claisen Rearrangement
Synlett, 2011Co-Authors: Makoto Inai, Takeshi Nishii, Shingo Mukoujima, Tomoyuki Esumi, Hiroto Kaku, Keiko Tominaga, Hiroaki Abe, Mitsuyo Horikawa, Tetsuto TsunodaAbstract:The total synthesis of (+)-brefeldin C was accomplished. Anasymmetric Aza-Claisen Rearrangement developed by our laboratorywas employed to construct the C-4 and C-5 stereogenic centers of(+)-brefeldin C as a key step.
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Total synthesis of the (+)-antimycin A3 family: structure elucidation of (+)-antimycin A3a
Tetrahedron Letters, 2003Co-Authors: Takeshi Nishii, Shiho Suzuki, Katsuyoshi Yoshida, Kozue Arakaki, Tetsuto TsunodaAbstract:(+)-Antimycin A3a (AA3a), one component of the natural antibiotic antimycin A3, was synthesized using an asymmetric Aza-Claisen Rearrangement. The stereochemistry at the 2′ position on the acyloxy side chain of AA3a was established as S-configuration by comparison of the synthetic AA3a and the natural AA3a.
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A total synthesis of (−)-antimycin A3b
Tetrahedron Letters, 2000Co-Authors: Tetsuto Tsunoda, Takeshi Nishii, Makoto Yoshizuka, Chise Yamasaki, Tomonori Suzuki, Sho ItoAbstract:Abstract (−)-Antimycin A 3b , the antipode of natural antibiotic antimycin A 3b , was synthesized utilizing the asymmetric Aza-Claisen Rearrangement.
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A Stereoselective Synthesis of(-)-Isoiridomyrmecin. Application of the Asymmetric Aza-Claisen Rearrangement.
Chemistry Letters, 1994Co-Authors: Tetsuto Tsunoda, Shinji Tatsuki, K. Kataoka, Sho ItoAbstract:(−)-Isoiridomyrmecin was synthesized stereoselectively in 6 steps starting from 1-hydroxymethyl-5-methylcyclopentene and utilizing tlle asymmetric Aza-Claisen Rearrangement as a key step.
Michael D. Swift - One of the best experts on this subject based on the ideXlab platform.
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A stereoselective synthesis of (+)-physoperuvine using a tandem Aza-Claisen Rearrangement and ring closing metathesis reaction.
Organic & biomolecular chemistry, 2009Co-Authors: Ahmed M. Zaed, Michael D. Swift, Andrew SutherlandAbstract:A stereoselective synthesis of (+)-physoperuvine, a tropane alkaloid from Physalis peruviana Linne has been developed using a one-pot tandem Aza-Claisen Rearrangement and ring closing metathesis reaction to form the key amino-substituted cycloheptene ring.
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Tandem Aza-Claisen Rearrangement and ring-closing metathesis reactions: the stereoselective synthesis of functionalised carbocyclic amides
Tetrahedron Letters, 2009Co-Authors: Michael D. Swift, Adele Donaldson, Andrew SutherlandAbstract:A one-pot, tandem process has been developed for the efficient synthesis of functionalised carbocyclic amides. A substituted cyclopentenyl trichloroacetamide was synthesised using a tandem thermal Aza-Claisen Rearrangement and RCM process, while an analogous cyclohexenyl trichloroacetamide was generated with high diastereoselectivity using a tandem MOM-ether directed metal-catalysed Aza-Claisen Rearrangement and RCM process.
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Investigation of metal mediated reactions for natural product synthesis
2009Co-Authors: Michael D. SwiftAbstract:During the course of the studies outlined in this thesis, an ether-directed Pd(II)-catalysed Aza-Claisen Rearrangement reaction that had previously been developed by the Sutherland group was expanded to include more functionalised Rearrangement substrates. This methodology has been applied for the synthesis of several natural products including dihydroxylated-amino acids. Further investigation of substrates for the Rearrangement led to the synthesis of other substituted trichloroacetimidates. Rearrangement of these compounds demonstrated the role of steric strain on the stereocontrol of the Rearrangement and also highlighted the role that solvent can have upon the diastereoselectivity of ether-directed Rearrangements. In addition to this, a novel tandem Aza-Claisen Rearrangement and ring closing metathesis reaction has been developed. This reaction allows the synthesis of cyclic allylic trichloroacetamides in excellent yields from simple allylic alcohols. The use of commercially available chiral Rearrangement catalysts allowed a highly enantioselective tandem process to be developed. Further development of this process has provided an ether-directed tandem Aza-Claisen Rearrangement and RCM reaction which occurs with high yield and diastereoselectivity to provide functionalised cyclic products. The use of these compounds for the total synthesis of the amaryllidaceae alkaloid (+)-gamma-lycorane was also investigated.
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A tandem Aza-Claisen Rearrangement and ring closing metathesis reaction for the synthesis of cyclic allylic trichloroacetamides.
Organic letters, 2007Co-Authors: Michael D. Swift, Andrew SutherlandAbstract:A one-pot tandem palladium(II)-catalyzed Aza-Claisen Rearrangement and ring closing metathesis process has been developed for the efficient synthesis of cyclic allylic trichloroacetamides. The use of chiral Pd(II) catalysts such as (S)-COP−Cl during the Rearrangement stage results in the preparation of these compounds in excellent yields and in high enantiomeric excess.
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A stereoselective synthesis of (2R,3S)-2-amino-3,4-dihydroxybutyric acid using an ether directed Aza-Claisen Rearrangement
Tetrahedron Letters, 2007Co-Authors: Michael D. Swift, Andrew SutherlandAbstract:A new approach for the stereoselective synthesis of (2R,3S)-2-amino-3,4-dihydroxybutyric acid, an α-amino acid from Lyophyllum ulmarium, has been accomplished using an ether directed Aza-Claisen Rearrangement. On investigation of optimal conditions for this key step it was shown for the first time that Au(I) can be used to catalyse this transformation.
Vrajesh R Shah - One of the best experts on this subject based on the ideXlab platform.
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design and synthesis of 1 benzazepine derivatives by strategic utilization of suzuki miyaura cross coupling aza claisen Rearrangement and ring closing metathesis
European Journal of Organic Chemistry, 2008Co-Authors: Sambasivarao Kotha, Vrajesh R ShahAbstract:A new and simple methodology has been realized for the synthesis of 7-substituted 2,3,4,5-tetrahydro-1-benzazepine derivatives with Suzuki-Miyaura cross-coupling, Aza-Claisen Rearrangement and ring-closing metathesis (RCM) the key steps. Here, o-allylacetanilide derivatives were obtained by Suzuki-Miyaura cross-coupling of the corresponding o-iodoacetanilides. The o-allylacetanilides, on N-allylation under phase-transfter catalysis conditions, provided diallyl derivatives as suitable precursors for RCM. These diallyl derivatives, on treatment with Grubbs' second-generation catalyst, gave the 1-benzazepine derivatives in moderate-to-good yields. These RCM products were found to be unstable and so they were hydrogenated to provide stable tetahydro-1-benzazepine derivatives 25-28. 1H-1-Benzazepin-2-one derivatives 44 and 45 were synthesized following a similar sequence. In addition, the Aza-Claisen Rearrangement was utilized as a key step in the preparation of RCM precursor 17.
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Design and Synthesis of 1‐Benzazepine Derivatives by Strategic Utilization of Suzuki–Miyaura Cross‐Coupling, Aza‐Claisen Rearrangement and Ring‐Closing Metathesis
European Journal of Organic Chemistry, 2008Co-Authors: Sambasivarao Kotha, Vrajesh R ShahAbstract:A new and simple methodology has been realized for the synthesis of 7-substituted 2,3,4,5-tetrahydro-1-benzazepine derivatives with Suzuki-Miyaura cross-coupling, Aza-Claisen Rearrangement and ring-closing metathesis (RCM) the key steps. Here, o-allylacetanilide derivatives were obtained by Suzuki-Miyaura cross-coupling of the corresponding o-iodoacetanilides. The o-allylacetanilides, on N-allylation under phase-transfter catalysis conditions, provided diallyl derivatives as suitable precursors for RCM. These diallyl derivatives, on treatment with Grubbs' second-generation catalyst, gave the 1-benzazepine derivatives in moderate-to-good yields. These RCM products were found to be unstable and so they were hydrogenated to provide stable tetahydro-1-benzazepine derivatives 25-28. 1H-1-Benzazepin-2-one derivatives 44 and 45 were synthesized following a similar sequence. In addition, the Aza-Claisen Rearrangement was utilized as a key step in the preparation of RCM precursor 17.
