Orchestrated Triple C?H Activation Reactions Using Two Directing Groups: Rapid Assembly of Complex Pyrazoles

A sequential triple C H activation reaction directed by a pyrazole and an amide group leads to the well‐controlled construction of sterically congested dihydrobenzo[e]indazole derivatives. This cascade reaction demonstrates that the often problematic competing C H activation pathways in the presence of multiple directing groups can be harvested by design to improve step economy in synthesis. Pyrazole as a relatively weak coordinating group is shown to direct C H activation for the first time.     

The Synthesis of Stable,Complex Organocesium Tetramic Acids through the Ugi Reaction and Cesium‐Carbonate‐Promoted Cascades

Two structurally unique organocesium carbanionic tetramic acids have been synthesized through expeditious and novel cascade reactions of strategically functionalized Ugi skeletons delivering products with two points of potential diversification. This is the first report of the use of multicomponent reactions and subsequent cascades to access complex, unprecedented organocesium architectures. Moreover, this article also highlights the first use of mild cesium carbonate as a cesium source for the construction of cesium organometallic scaffolds. Relativistic DFT calculations provide an insight into the electronic structure of the reported compounds.