Stereospecific Nitrogen Insertion Using Amino Diphenylphosphinates: An Aza-Baeyer-Villiger Rearrangement
Mike Ong, Marlene Arnold, Alexander W. Walz and Johannes M. Wahl*
*Department Chemie, Johannes Gutenberg-Universität, Duesbergweg 10-14, 55128 Mainz, Germany,
Email: wahl
uni-mainz.de
M. Ong, M. Arnold, A. W. Walz, J. M. Wahl, Org. Lett., 2022, 24, 6171-6175.
DOI: 10.1021/acs.orglett.2c02361
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Abstract
Amino diphenylphosphinates undergo ring expansion of cyclobutanones toward γ-lactams under mild conditions. Due to the ambivalent character of the aminating agent, rearrangement occurs from a Criegee-like intermediate prior to the formation of an oxime species. The migrating aptitude of adjacent groups is in line with the parent Baeyer-Villiger reaction.
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proposed reaction pathway
General Procedure for the Ring-Expansion of Cyclobutanones to 4-Substituted γ-Lactams
An oven dried tube was charged with aminating agent (550 µmol, 1.10 equiv.) and suspended in DMF (1.5 mL, 0.33 M). The corresponding cyclobutanone (500 µmol, 1.00 equiv.) was dissolved in DMF (1.0 mL, 0.50 M) and added to the mixture. The mixture was stirred at room temperature for 24 h. The solvent was concentrated under reduced pressure and NMR yield of the crude reaction mixture was determined by 1H NMR using dibromomethane (35.0 μL, 86.9 mg, 500 µmol) as the internal standard. The product was separated from the corresponding oxime byproduct by silica gel column chromatography.
Key Words
γ-lactams, Baeyer-Villiger reaction
ID: J54-Y2022
