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Organocatalytic Synthesis of ?-Trifluoromethyl Allylboronic Acids by Enantioselective 1,2-Borotropic Migration.

ABSTRACT: Chiral ?-substituted allylboronic acids were synthesized by asymmetric homologation of alkenylboronic acids using CF₃/TMS-diazomethanes in the presence of BINOL catalyst and ethanol. The chiral ?-substituted allylboronic acids were reacted with aldehydes or oxidized to alcohols in situ with a high degree of chirality transfer. The oxygen-sensitive allylboronic acids can be purified via their isolated diaminonaphthalene (DanH)-protected derivatives. The highly reactive purified allylboronic acids reacted in a self-catalyzed reaction at room temperature with ketones, imines, and indoles to give congested trifluoromethylated homoallylic alcohols/amines with up to three contiguous stereocenters.

SUBMITTER: Jonker SJT

PROVIDER: S-EPMC7760092 | biostudies-literature | 2020 Dec

REPOSITORIES: biostudies-literature

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Organocatalytic Synthesis of α-Trifluoromethyl Allylboronic Acids by Enantioselective 1,2-Borotropic Migration.

Jonker Sybrand J T SJT Jayarajan Ramasamy R Kireilis Tautvydas T Deliaval Marie M Eriksson Lars L Szabó Kálmán J KJ

Journal of the American Chemical Society 20201203 51

Chiral α-substituted allylboronic acids were synthesized by asymmetric homologation of alkenylboronic acids using CF<sub>3</sub>/TMS-diazomethanes in the presence of BINOL catalyst and ethanol. The chiral α-substituted allylboronic acids were reacted with aldehydes or oxidized to alcohols in situ with a high degree of chirality transfer. The oxygen-sensitive allylboronic acids can be purified via their isolated diaminonaphthalene (DanH)-protected derivatives. The highly reactive purified allylbo ...[more]

PMID: 33270462

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