Switchable Brønsted acid-catalyzed ring contraction of Cyclooctatetraene oxide towards the enantioselective synthesis of Cyloheptatrienyl-substituted homoallylic Alcohols and Oxaborinanes

Sendra, Jana ; Salvado, Oriol ; Pedrón, Manuel (Universidad de Zaragoza) ; Reyes, Efraim ; Tejero, Tomás (Universidad de Zaragoza) ; Fernández, Elena ; Merino, Pedro (Universidad de Zaragoza) ; Vicario, Jose L.

Resumen: The ability of cyclooctatetraene oxide to undergo two sequential ring contraction events under mild conditions, using Brønsted acid catalysis, has been studied in detail. We have found that the selectivity can be controlled by the acidity of the catalyst and by the temperature, being able to obtain selectively either the cycloheptatriene carbaldehyde product, arising from a single ring-contraction event, or phenylacetaldehyde that is formed after a second ring contraction process. A complete mechanistic picture of the reaction and a rationale behind the influence of the catalyst is provided based on both experimental and computational data. Finally, this acid-catalyzed ring contraction has been coupled with an in situ enantioselective allylation reaction, delivering enantioenriched cycloheptatrienyl-substituted homoallylic alcohols when it is carried out in the presence of a chiral phosphoric acid catalyst. These homoallylic alcohols have also been converted into enantioenriched oxaborinanes through copper-catalyzed nucleophilic borylation/cyclization protocol.

Idioma: Inglés

DOI: 10.1002/adsc.202300121

Año: 2023

Publicado en: Advanced Synthesis and Catalysis 365, 7 (2023), 1058-1071
ISSN: 1615-4150

Factor impacto JCR: 4.4 (2023)

Categ. JCR: CHEMISTRY, ORGANIC rank: 8 / 58 = 0.138 (2023) - Q1 - T1
Categ. JCR: CHEMISTRY, APPLIED rank: 19 / 74 = 0.257 (2023) - Q2 - T1

Factor impacto CITESCORE: 9.4 - Organic Chemistry (Q1) - Catalysis (Q2)

Factor impacto SCIMAGO: 1.02 - Organic Chemistry (Q1) - Catalysis (Q2)

Financiación: info:eu-repo/grantAgreement/ES/DGA/E34-20R
Financiación: info:eu-repo/grantAgreement/ES/MCINN/PRE2018-083532
Financiación: info:eu-repo/grantAgreement/ES/MICINN/PID2019-104090RB-100
Financiación: info:eu-repo/grantAgreement/ES/MICINN/PID2019-109674GB-I00
Financiación: info:eu-repo/grantAgreement/ES/MICIU-FEDER/PID2020-118422GB-I00

Tipo y forma: Article (Published version)

Área (Departamento): Área Química Orgánica (Dpto. Química Orgánica)