Synthesis of Polysubstituted Furans via Rh(II)-Catalyzed [2 + 3] Annulation of <i>N</i>-Sulfonyl-1,2,3-triazoles with Enaminones
Xiaoqiang Lei, Juan Feng, Qing‐Lan Guo, Yuanhe Li, Jian‐Gong Shi
Abstract
An unprecedented [2 + 3] annulation of N -sulfonyl-1,2,3-triazoles with enaminones is reported for the access of polysubstituted furans. The key to the success of the transformations lies in the use of Rh(II)–Brønsted acid as cooperative catalysts. Unlike the conventional annulations of N -sulfony-l-1,2,3-triazoles, the Rh(II)-azavinyl carbenes species play dual functions in this work, enabled by the cleavage of the C(sp 2 ) − N bond. The mechanism studies suggested that an intermolecular rearrangement of the TsNH – group is crucial to the annulation process.
Topics & Concepts
AnnulationChemistryCatalysisSulfonylMedicinal chemistryIntermolecular forceCombinatorial chemistryCleavage (geology)Dual roleStereochemistryMoleculeOrganic chemistryGeotechnical engineeringFracture (geology)AlkylEngineeringCyclopropane Reaction MechanismsCatalytic C–H Functionalization MethodsCatalytic Alkyne Reactions