Functionalized esters as bis-electrophiles in a silicon-induced domino synthesis of annulated carbocycles

Genrich, Florian; Harms, Guido; Schaumann, Ernst; Gjikaj, Mimoza; Adiwidjaja, Ḡunadi

doi:10.1016/j.tet.2009.01.119

Cited by 11 publications

(6 citation statements)

References 32 publications

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“…MS: m / z = 192.8 [M–H] − , MS m / z : 217.0 [M+Na] + . The analytical data are in agreement with the literature …”

Section: Methodssupporting

confidence: 90%

“…3-(2-Carboxyphenyl)propionic acid (7): 1 H NMR (500 MHz, CDCl 3 ) δ: 2.73 (t, 3 J = 7.8 Hz, 2H), 3.42 (t, 3 J = 7.9 Hz, 2H), 7.35 (m, 2H), 7.52 (m, 1H), 8.06 (d, 3 J = 7.7 Hz, 1H). 13 26 Intramolecular Friedel−Crafts Acylation under the Formation of 4-Carboxylic-Acid-Substituted Indan-1-one. 3-(2-Carboxyphenyl)propionic acid (7, 500 mg, 2.57 mmol, 1.00 equiv) is dissolved in sulfuric acid (30 mL).…”

Section: ■ Experimental Sectionmentioning

confidence: 99%

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Chemoenzymatic Synthesis of a Chiral Ozanimod Key Intermediate Starting from Naphthalene as Cheap Petrochemical Feedstock

et al. 2019

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Ozanimod represents a recently developed, promising active pharmaceutical ingredient (API) molecule in combating multiple sclerosis. Addressing the goal of a scalable, economically attractive, and technically feasible process for the manufacture of this drug, a novel alternative synthetic approach toward (S)-4-cyano-1-aminoindane as a chiral key intermediate for ozanimod has been developed. The total synthesis of this intermediate is based on the utilization of naphthalene as a readily accessible, economically attractive, and thus favorable petrochemical starting material. At first, naphthalene is transformed into 4-carboxy-indanone within a four-step process by means of an initial Birch reduction, followed by an isomerization of the CC double bond, oxidative CC cleavage, and intramolecular Friedel–Crafts acylation. The transformation of the 4-carboxy-indanone into (S)-4-cyano-1-aminoindane then represents the key step for introducing the chirality and the desired absolute S configuration. When evaluating complementary biocatalytic approaches based on the use of a lipase and transaminase, respectively, the combination of a chemical reductive amination of the 4-carboxyindanone followed by a subsequent lipase-catalyzed resolution turned out to be the most efficient route, leading to the desired key intermediate (S)-4-cyano-1-aminoindane in satisfactory yield and with excellent enantiomeric excess of 99%.

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“…MS: m / z = 192.8 [M–H] − , MS m / z : 217.0 [M+Na] + . The analytical data are in agreement with the literature …”

Section: Methodssupporting

confidence: 90%

Section: ■ Experimental Sectionmentioning

confidence: 99%

Chemoenzymatic Synthesis of a Chiral Ozanimod Key Intermediate Starting from Naphthalene as Cheap Petrochemical Feedstock

et al. 2019

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“…6,11 After protection 12 of the alcohol as TBS-ether, ester 3 13 is reduced 14 to benzyl alcohol 4 15 by DIBAL in high yield (Scheme 3).…”

Section: Resultsmentioning

confidence: 99%

“…Following epoxide ring opening by the carbanion, a reversible C?O silyl migration (Brook rearrangement) 2 is the key step. The method has been expanded using bis-epoxides, 3 vinyl-epoxides, 4 epoxy-aziridines 5 or multifunctional esters [6][7][8] as biselectrophilic reaction partners of the carbanion. Best results are usually obtained for cyclopentane synthesis, while the sevenmembered rings are only obtained in modest yields.…”

Section: Introductionmentioning

confidence: 99%

Silicon- and sulfur-mediated synthesis of benzoannulated cyclooctanols

Genrich

Schaumann

2009

Tetrahedron Letters

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“…Dicarboxylic acids 8a-8e were prepared according to published procedures [31][32][33][34][35] (see Supporting Information for details). Melting points were determined with a Stuart SMP50 instrument in open capillary tubes.…”

Section: Methodsmentioning

confidence: 99%