C–O Functionalization of α-Oxyboronates: A Deoxygenative <i>gem</i>-Diborylation and <i>gem</i>-Silylborylation of Aldehydes and Ketones
作者:Lu Wang、Tao Zhang、Wei Sun、Zeyu He、Chungu Xia、Yu Lan、Chao Liu
DOI:10.1021/jacs.7b02518
日期:2017.4.12
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
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,