Carbon Dioxide Based N‐Formylation of Amines Catalyzed by Fluoride and Hydroxide Anions

Abstract We described herein a simple approach for N‐formylation with CO 2 and hydrosilane reducing agents. Fluoride and hydroxide salts efficiently catalyzed the reaction, principally through activation of the hydrosilanes, which led to hydrosilane reactivities comparable to those of NaBH 4 /LiAlH 4 . Consequently, the N‐formylation of amines with CO 2 could be achieved at room temperature and atmospheric pressure. The mechanism of these anionic catalysts contrasts that of the currently reported systems, for which activation of CO 2 is the key mechanistic step. Using tetrabutylammonium fluoride as a simple ammonium salt catalyst, the N‐formylated products of both aliphatic and aromatic amines could be obtained in excellent yields with high selectivities.