A Convenient Mild Two-Step Conversion of Imines to Secondary and Tertiary Amides

Gold-Catalyzed Formal [3 + 2] Cycloaddition of Ynamides with 4,5-Dihydro-1,2,4-oxadiazoles: Synthesis of Functionalized 4-Aminoimidazoles

“…Inspired by this work and our continuous interests on the chemistry of ynamides, , we envisioned that 4,5-dihydro-1,2,4-oxadiazoles might act as a new type of nitrene-transfer reagent because these substrates might also undergo the N–O bond cleavage reactions under the appropriate reaction conditions. For example, the N–O bond in 4,5-dihydro-1,2,4-oxadiazoles can be reductively cleaved through H 2 /Raney nickel or under basic conditions . The development of such transformations would be of great interest for the synthesis of functionalized 4-aminoimidazoles from ynamides and easily available heterocyclic substrates (Scheme , B).…”

Oxidative Dearomatization of PLP in Thiamin Pyrimidine Biosynthesis in Candida albicans

“…However, treatment of dephosphorylated P 15.9 , under conditions known to convert nitrile oxides to nitriles, gave a product that comigrated, by HPLC (Figures S33−S36) and LC-MS (Figure 7f), with a synthetic sample of cyano-pyridoxal (34) consistent with this structural assignment. 31,47 Our mechanistic proposal for the formation of 49 and 50 is shown in Figure 7g. Oxidative dearomatization of 48 to give 53 follows the same pathway as the PLP oxidative dearomatization shown in Figure 2 (7−10).…”

“…However, treatment of dephosphorylated P 15.9 , under conditions known to convert nitrile oxides to nitriles, gave a product that comigrated, by HPLC ( Figures S33–S36 ) and LC-MS ( Figure 7 f), with a synthetic sample of cyano-pyridoxal ( 34 ) consistent with this structural assignment. 31 , 47 …”

AcetonitrileN-Oxide

“…thioesters → 1,4,2-oxathiazolines, 5 imines → 1,2,4-oxadiazolines, 22 and isothiocyanates → imino-1,4,2-oxathiazoles 23 ). …”