A Tunable Route for the Synthesis of Azomethine Imines and β-Aminocarbonyl Compounds from Alkenes
摘要:
Cyclic azomethine imines possessing a beta-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 beta-aminoamides, beta-aminoesters, and beta-amino acids.