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.

Mild and highly efficient I2 and Et3N aided cyclodeselenization of in situ generated selenosemicarbazide is described to obtain 2-amino-1,3,4-oxadiazole peptidomimetics.

Herein we demonstrate a chemoselective reaction of Nβ‐protected amino alkyl sulfonyl azides with in situ generated Nα‐protected amino acid selenocarboxylates via step wise intramolecular cyclization followed by decomposition to obtain N‐acyl sulfonamide tethered peptidyl conjugates. The protocol offers the synthesis of orthogonally protected N‐acyl sulfonamide tethered peptidomimetics under simple and mild reaction conditions employing commercially available amino acids in presence of NaBH2Se3 as a selenating agent. Also, the synthesis of N‐acyl sulfonamide tethered amino acid and aryl conjugates were accomplished as an extension of the above strategy.

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Chiral amino acid-derived formamides represent one of the most versatile components in multicomponent reactions. Herein, we describe a facile synthesis of N β -protected amino sulfenyl methyl formamides and sulfonyl methyl formamides via the Mannich reaction of N α -protected amino alkyl thiols followed by oxidation using 3-chloroperbenzoic acid (m-CPBA). This protocol is applicable to a wide range of Fmoc-and Cbz-protected amino acids. Notably, the reaction provides high yield and retains the stereochemistry of the chiral center of the starting component.