Synthesis of Polysubstituted 5-Aminooxazoles from α- Diazocarbonyl Esters and α-Isocyanoacetamides

Abstract

A novel and efficient reaction for the synthesis of 2-keto-5-aminooxazoles is developed. The entire sequence is realized by simply heating a xylene solution of alpha-diazocarbonyl esters and alpha-isocyanoacetamides without any promoters. A possible mechanism for the entire sequence is proposed.

Synthesis of Polysubstituted Maleimides via Metal-Free Cascade Reaction of Isocyanides and α-Diazoketones

“…On the basis of these results as well as previous reports, ,, a plausible mechanism was proposed ( 3ac as the example, Scheme ). First, substrate 1a is triggered by heat to generate carbene, which followed by a subsequent Wolff rearrangement to give ketene A .…”

Zinc Bromide Promoted Coupling of Isonitriles with Carboxylic Acids To Form 2,4,5‐Trisubstituted Oxazoles

“…[25,26] In summary, we have developed an unprecedented zinc bromide mediated co-trimerization of isonitriles with carboxylic acids as an efficient synthesis of 2,4,5-trisubstituted oxazoles. [27] A broad range of carboxylic acids, including aromatic, heteroaromatic, aliphatic, and a,b-unsaturated substrates, participated readily in this reaction. The structure of (tBuNC) 2 ZnBr 2 was fully characterized and provided useful hints regarding the reaction mechanism.…”

Modern Organic Synthesis with α-Diazocarbonyl Compounds

“…313 The elegant work of Mander and co-workers has demonstrated the power of the intramolecular Buchner reaction in the construction of highly functionalized polycyclic molecules. 315−317 A case in point is the synthesis of the bioactive diterpenoid harringtonolide (112), which contains a cycloheptatrienone ring bearing four contiguous substituents (Scheme 122). 317 Additionally, Mander also used a similar strategy in the total synthesis of gibberellin derivatives, where the molecular architecture prevented isomerization of the norcaradiene (Scheme 123).…”