A Tunable Route for the Synthesis of Azomethine Imines and β‑Aminocarbonyl Compounds from Alkenes

Cyclic azomethine imines possessing a β-aminocarbonyl
motif
are accessed from simple alkene and hydrazone starting materials.
A thermal, concerted alkene aminocarbonylation pathway involving an
imino-isocyanate intermediate is proposed and supported by DFT calculations.
A notable feature of the process is the steric shielding present in
the dipoles formed, which allows for facile purification of the products
by chromatography or crystallization. In addition, a fluorenone-derived
reagent is reported, which provides reactivity with several alkene
classes and allows for mild derivatization of the dipoles into β-aminoamides,
β-aminoesters, and β-amino acids.