190393-65-8Relevant articles and documents
Staudinger/aza-Wittig reaction to access Nβ-protected amino alkyl isothiocyanates
Santhosh,Durgamma,Shekharappa,Sureshbabu, Vommina V.
, p. 4874 - 4880 (2018/07/15)
A unified approach to access Nβ-protected amino alkyl isothiocyanates using Nβ-protected amino alkyl azides through a general strategy of Staudinger/aza-Wittig reaction is described. The type of protocol used to access isothiocyanates depends on the availability of precursors and also, especially in the amino acid chemistry, on the behavior of other labile groups towards the reagents used in the protocols; fortunately, we were not concerned about both these factors as precursor-azides were prepared easily by standard protocols, and the present protocol can pave the way for accessing title compounds without affecting Boc, Cbz and Fmoc protecting groups, and benzyl and tertiary butyl groups in the side chains. The present strategy eliminates the need for the use of amines to obtain title compounds and thus, this method is step-economical; additional advantages include retention of chirality, convenient handling and easy purification. A few hitherto unreported compounds were also prepared, and all final compounds were completely characterized by IR, mass, optical rotation, and 1H and 13C NMR studies.
Synthesis of optically active imidazolines, azapenams, dioxocyclams, and bis-dioxocyclams
Hsiao, Yi,Hegedus, Louis S.
, p. 3586 - 3591 (2007/10/03)
Optically active 4-methyl-4-carbomethoxy-Δ2-imidazoline was efficiently synthesized on a multigram scale. Photolysis with (methoxymethylcarbene)chromium complex produced the optically active azapenam in good yield and with high stereoselectivity. Acid-catalyzed dimerization followed by reduction produced the corresponding optically active dioxocyclam in good yield. Using a bis-carbene complex, an optically active bis-dioxocyclam was produced in excellent yield.
