Generation and Reactivity of 2-Amido-1,3-diaminoallyl Cations: Cyclic Guanidine Annulations via Net (3 + 2) and (4 + 3) Cycloadditions
V. Raghavendra Rao Kovvuri, Haoran Xue, Daniel Romo
Abstract
Toward a method for direct conversion of alkenes to cyclic guanidines, we report that 1,3-dipolar cycloadditions of 2-amido-1,3-diamino allylic cations with alkenes provide a new method for direct cyclic guanidine annulation. Generated under oxidative conditions, the 2-amido-1,3-diaminoallyl cations react as 1,3-dipoles providing rapid access to 2-amino imidazolines through net (3 + 2) cycloadditions. The utility is demonstrated through a concise synthesis of the oroidin alkaloid, phakellin. The described 1,3-dipole also participates in net (4 + 3) cycloadditions with dienes.
Topics & Concepts
ChemistryGuanidineReactivity (psychology)AnnulationAllylic rearrangementMedicinal chemistryCombinatorial chemistryStereochemistryOrganic chemistryCatalysisAlternative medicineMedicinePathologySynthesis and Reactions of Organic CompoundsAsymmetric Synthesis and CatalysisSynthesis and Catalytic Reactions