An efficient synthesis of cyclic urethanes from Boc-protected amino acids through a metal triflate-catalyzed intramolecular diazocarbonyl insertion reaction

Diazocarbonyl derivatives of amino acids: unique chiral building blocks for the synthesis of biologically active compounds

This review deals with applications of chiral α-amino diazoketones, α-amino acid derivatives, in the synthesis of various biologically active compounds. General approaches to the synthesis of chiral α-amino diazoketones, including the Arndt – Eistert reaction, acylation of trimethylsilyldiazomethanes, etc., are discussed. Due to the presence of three functional groups, these building blocks can be used to produce a wide range of organic compounds with potential physiological activity, ranging from various heterocyclic compounds to peptidomimetics. Methods for the synthesis of β-amino acid-containing peptides and depsipeptides, amino acid derivatives and heterocyclic compounds with three- to seven-membered rings are considered.

The bibliography includes 226 references.

OC, Ahmad A, Burtoloso ACB. Synthesis of Oxazinanones: Intramolecular Cyclization of Amino Acid-Derived Diazoketones via Silica-Supported HClO4 Catalysis

A Brønsted acid catalyzed intramolecular cyclization of N-Cbz-protected diazoketones, derived from α-amino acids, is described. The reaction proceeds under metal-free conditions and is promoted by ecofriendly silica-supported HClO₄ as the catalyst and methanol as the solvent. This transformation enables the short synthesis of various 1,3-oxazinane-2,5-diones under mild reaction conditions and in good yields (up to 90%). The set-up is very simple; by just mixing all reagents together with no work-up necessary before purification, this protocol takes a greener approach.

1,3-Oxazinan-2-ones via carbonate chemistry: a facile, high yielding synthetic approach

A high yielding synthesis of 1,3-oxazinan-2-ones starting from 3-amino-1-propanols and ethylene carbonate (EC) in the presence of catalytic amount of triazabicyclodecene (TBD) is herein reported. The formation of six-membered cyclic carbonates was achieved by intermolecular cyclization reaction via double BAc2 mechanism. Cyclization reactions have been carried out in neat as EC acted both as solvent and reagent. Pure 1,3-oxazinan-2-ones were isolated in high yield by simple liquid-liquid extraction. Further purification can be achieved by recrystallization. The reaction resulted of general application on different substrates including an aryl bis(3-amino-proan-1-ol) compound.