122123-77-7Relevant articles and documents
Selective formation of γ-lactams via C-H amidation enabled by tailored iridium catalysts
Hong, Seung Youn,Park, Yoonsu,Hwang, Yeongyu,Kim, Yeong Bum,Baik, Mu-Hyun,Chang, Sukbok
, p. 1016 - 1021 (2018)
Intramolecular insertion of met al nitrenes into carbon-hydrogen bonds to form γ-lactam rings has traditionally been hindered by competing isocyanate formation. We report the application of theory and mechanism studies to optimize a class of pentamethylcyclopentadienyl iridium(III) catalysts for suppression of this competing pathway. Modulation of the stereoelectronic properties of the auxiliary bidentate ligands to be more electron-donating was suggested by density functional theory calculations to lower the C-H insertion barrier favoring the desired reaction. These catalysts transform a wide range of 1,4,2-dioxazol-5-ones, carbonylnitrene precursors easily accessible from carboxylic acids, into the corresponding γ-lactams via sp3 and sp2 C-H amidation with exceptional selectivity. The power of this method was further demonstrated by the successful late-stage functionalization of amino acid derivatives and other bioactive molecules.
Total syntheses of (±) and (-)-stemoamide
Jacobi, Peter A.,Lee, Kyungae
, p. 4295 - 4303 (2007/10/03)
(±)-Stemoamide (1) was prepared in seven steps beginning with y- chlorobutryl chloride (20) and succinimide (15), which were efficiently converted to the key alkyne oxazole 17 on a multigram scale. Intramolecular (Diels-Alder)-(retro-Diels-Alder) reaction of 17 then gave butenolide 12b directly upon aqueous workup. The remaining two stereocenters in 1 were established in a single step by a highly selective reduction of 12b (NaBH4/NiCl2), followed by equilibration to the thermodynamically favored natural configuration. In analogous fashion (-)-stemoamide (1) was prepared beginning with L-pyroglutamic acid (S-35).
A NEW AMIDOALKYNYLATION USING ALKYNYLZINC REAGENT
Mori, Sachio,Iwakura, Hikozo,Takechi, Shozo
, p. 5391 - 5394 (2007/10/02)
A new amidoalkynylation using alkynylzinc reagent was developed and successfully applied to various α-thio-lactams including 6.
