CO 2 transformations using a one-pot two-step method are presented herein. The purpose of the method is to give access to a variety of valueadded products and notably to generate chiral carbon centers. The crucial first step consists in the selective double hydroboration of CO 2 catalyzed by an iron hydride complex. The product obtained with this 4 e reduction is a rare bis(boryl)acetal, compound 1, which is subjected in situ to three different reactions in a second step. The first reaction concerns a condensation reaction with (diisopropyl)phenylamine affording the corresponding imine 2. In the second and third reaction, intermediate 1 reacts with triazol-5-ylidene (Enders' carbene) to afford compounds 3 or 4, depending on the reaction conditions. In both compounds, CC bonds are formed, and chiral centers are generated from CO 2 as the only source of carbon. Compound 4 exhibits two chiral centers obtained in a diastereoselective manner in a formose-type mechanism. We proved that the remaining boryl fragment plays a key role in this unprecedented stereocontrol. The interest of the method stands on the reactive and versatile nature of 1, giving rise to various complex molecules from a single intermediate. The complexity of a two-step method is compensated by the overall short reaction time (2 h for the larger reaction time), and mild reaction conditions (25 °C to 80 °C and 1 to 3 atm of CO 2).

CO 2 transformations using a one-pot two-step method are presented herein. The purpose of the method is to give access to a variety of valueadded products and notably to generate chiral carbon centers. The crucial first step consists in the selective double hydroboration of CO 2 catalyzed by an iron hydride complex. The product obtained with this 4 e reduction is a rare bis(boryl)acetal, compound 1, which is subjected in situ to three different reactions in a second step. The first reaction concerns a condensation reaction with (diisopropyl)phenylamine affording the corresponding imine 2. In the second and third reaction, intermediate 1 reacts with triazol-5-ylidene (Enders' carbene) to afford compounds 3 or 4, depending on the reaction conditions. In both compounds, C-C bonds are formed, and chiral centers are generated from CO 2 as the only source of carbon. Compound 4 exhibits two chiral centers obtained in a diastereoselective manner in a formose-type mechanism. We proved that the remaining boryl fragment plays a key role in this unprecedented stereocontrol. The interest of the method stands on the reactive and versatile nature of 1, giving rise to various complex molecules from a single intermediate. The complexity of a two-step method is compensated by the overall short reaction time (2 h for the larger reaction time), and mild reaction conditions (25 °C to 80 °C and 1 to 3 atm of CO 2 ). Video LinkThe video component of this article can be found at https://www.jove.com/video/60348/ 20 . In this latter reaction, C-C coupling and chiral carbon centers are obtained.