A deoxygenative gem-diborylation and gem-silylborylation of aldehydes and ketones is described. The key for the success of this transformation is the base-promoted C-O bond borylation or silylation of the generated α-oxyboronates. Experimental and theoretical studies exhibit that the C-O bond functionalization proceeds via an intramolecular five-membered transition-state (9-ts) boryl migration followed by a 1,2-metalate rearrangement with OBpin as a leaving group. The transformation occurs with an inversion on the carbon center. Direct conversion of aldehydes and ketones to gem-diboron compounds was achieved by combining copper catalysis with this base-promoted C-OBpin borylation. Various aldehydes and ketones were deoxygenatively gem-diborylated. gem-Silylborylation of aldehydes and ketones were achieved by a stepwise operation, in which B2pin2 initially react with those carbonyls followed by a silylation with Bpin-SiMe2Ph.

中文翻译：

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α-氧硼酸酯的 C-O 官能化：醛和酮的脱氧宝石-二硼化和宝石-甲硅烷基硼化

描述了醛和酮的脱氧宝石二硼化和宝石甲硅烷基硼化。这种转化成功的关键是生成的 α-羟基硼酸酯的碱促进 CO 键硼化或甲硅烷基化。实验和理论研究表明，CO 键功能化是通过分子内五元过渡态 (9-ts) 硼基迁移，然后以 OBpin 作为离去基团进行 1,2-金属酸盐重排进行的。转变发生在碳中心上的反转。通过将铜催化与这种碱促进的 C-OBpin 硼酸化相结合，可以实现醛和酮直接转化为铕二硼化合物。各种醛和酮被脱氧宝石二硼酸化。醛和酮的 gem-Silylborylation 是通过逐步操作实现的，