On-column N-dearylation of 2-azetidinones by silica-supported ceric ammonium nitrate

Divergent, stereoselective access to heterocyclic α,α-quaternary- and β2,3,3-amino acid derivatives from a N-Pmp-protected Orn-derived β-lactam

“…[27][28][29] These moieties, exemplified by the N-p-methoxyphenyl group (Pmp), can easily be removed by ceric ammonium nitrate (CAN) under relatively mild conditions. [30][31][32] In addition, this oxidative cleavage is highly compatible with a large number of functional groups, making this protection/deprotection procedure a good option for our purposes. Thus, the first step of the new synthetic sequence involved the attachment of the Pmp group into the suitable ornithine derivative 4 (Scheme 1).…”

β‐Lactam Preparation via Staudinger Reaction with Activated Dimethylsulfoxide

“…Column chromatography was performed on silica gel 60 (Merck, 70–230 mesh). Spectral data for 3a , 3b , 3g , 3j , 3k , 3l , 3m , 3o , 3p , 5a , 6a , 6b , and 8a , 8b have been previously reported [18b,c,19].…”

One-step Synthesis of β-lactams Using Cyanuric Fluoride

“…Spectral data for 4a-f and 4h-j have been previously reported. 14,16,20,27,28 Synthesis of 2-azetidinones (4a-m); general procedure Cyanuric fluoride (1.5 mmol) was added to a solution of substituted acetic acids (1.5 mmol), imines (1.0 mmol) and triethylamine (5.0 mmol) in dry CH 2 Cl 2 (20 mL) at room temperature and the mixture was stirred overnight. The reaction mixture was washed successively with saturated NaHCO 3 (20 mL) and brine (10 mL).…”