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Coumarins by Direct Annulation: ?-Borylacrylates as Ambiphilic C₃ -Synthons.

ABSTRACT: Modular ?-borylacrylates have been validated as programmable, ambiphilic C₃ -synthons in the cascade annulation of 2-halo-phenol derivatives to generate structurally and electronically diverse coumarins. Key to this [3+3] disconnection is the BPin unit which serves a dual purpose as both a traceless linker for C(sp² )-C(sp² ) coupling, and as a chromophore extension to enable inversion of the alkene geometry via selective energy transfer catalysis. Mild isomerisation is a pre-condition to access 3-substituted coumarins and provides a handle for divergence. The method is showcased in the synthesis of representative natural products that contain this venerable chemotype. Facile entry into ?-expanded estrone derivatives modified at the A-ring is disclosed to demonstrate the potential of the method in bioassay development or in drug repurposing.

SUBMITTER: Wienhold M

PROVIDER: S-EPMC7839779 | biostudies-literature | 2020 Sep

REPOSITORIES: biostudies-literature

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Coumarins by Direct Annulation: β-Borylacrylates as Ambiphilic C3 -Synthons.

Wienhold Max M Molloy John J JJ Daniliuc Constantin G CG Gilmour Ryan R

Angewandte Chemie (International ed. in English) 20201109 2

Modular β-borylacrylates have been validated as programmable, ambiphilic C3 -synthons in the cascade annulation of 2-halo-phenol derivatives to generate structurally and electronically diverse coumarins. Key to this [3+3] disconnection is the BPin unit which serves a dual purpose as both a traceless linker for C(sp2 )-C(sp2 ) coupling, and as a chromophore extension to enable inversion of the alkene geometry via selective energy transfer catalysis. Mild isomerisa ...[more]

PMID: 32975367

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