Wednesday, April 22, 2020

SCHMIDT REACTION

Schmidt Reaction











The acid-catalysed reaction of hydrogen azide with electrophiles, such as carbonyl compounds, tertiary alcohols or alkenes. After a rearrangement and extrusion of N2, amines, nitriles, amides or imines are produced.



Mechanism of the Schmidt Reaction



Reaction of carboxylic acids gives acyl azides, which rearrange to isocyanates, and these may be hydrolyzed to carbamic acid or solvolysed to carbamates. Decarboxylation leads to amines.




The reaction with a ketone gives an azidohydrin intermediate, which rearranges to form an amide:




Alkenes are able to undergo addition of HN3 as with any HX reagent, and the resulting alkyl azide can rearrange to form an imine:




Tertiary alcohols give substitution by azide via a carbenium ion, and the resulting alkyl azide can rearrange to form an imine.


Recent Literature




Chemoselective Schmidt Reaction Mediated by Triflic Acid: Selective Synthesis of Nitriles from Aldehydes




Tf2O-Promoted Intramolecular Schmidt Reaction of the ω-Azido Carboxylic Acids




Efficient, One-Pot, BF3·OEt2-Mediated Synthesis of Substituted N-Aryl Lactams


Interruption of Formal Schmidt Rearrangement/Hosomi-Sakurai Reaction of Vinyl Azides with Allyl/Propargylsilanes




Gold(I)-Catalyzed Intramolecular Acetylenic Schmidt Reaction

No comments:

Post a Comment

BIOMOLECULES CHEMISTRY CLASS 12

                           BIOMOLECULES ( CHEMISTRY )        Carbohydrates:  Polyhydroxy aldehydes or polyhydroxy ketones or compounds on hy...