Unusual Lewis-acid catalyzed formal (3+3)-cycloaddition of azomethine imines and nitrones to N-vinylpyrroles

Oxidative (3+3) Cycloaddition/Ring-Opening Reactions of Simple Urea Derivatives and N,N'-Cyclic Azomethine Imines to Construct 1,2,3,5-Tetrazine-4(1H)-one Derivatives

A novel oxidative (3 + 3) cycloaddition/ring-opening reaction of N,N'-cyclic azomethine imines with the in situ generated diaza-oxylallyl cations from simple urea derivatives in the presence of base and PhI(OAc)₂ has been developed. This transformation performs well over a broad substrate scope, which provides facile and rapid access to 1,2,3,5-tetrazine-4(1H)-one derivatives in good yields.

An overview of the reactions involving azomethine imines over half a decade

Azomethine imines constitute a versatile class of 1,3-dipoles which was used extensively for biologically relevant N-heterocycle synthesis – a five-year recap.

Ambient access to a new family of pyrrole-fused pyrazine nitrones via 2-carbonyl-N-allenylpyrroles

The chemo-, regio- and stereoselective synthesis of pyrrole-fused pyrazine nitrones via the direct reaction of 2-carbonyl-N-allenylpyrroles (readily accessible from the corresponding NH-pyrroles) with hydroxyl amine hydrochloride has been developed.

DABCO-mediated [3+3] cycloaddition of azomethine imines with in situ generated nitrile oxides from hydroximoyl chlorides

A novel cross 1,3-dipolar cycloaddition between azomethine imines with in situ generated nitrile oxides has been developed. This is the first example of employing a reaction partner containing two heteroatoms in the [3+3] cycloaddition involving azomethine imines. This strategy not only provides structurally diverse N,O-heterocycles but also greatly enriches the chemistry of azomethine imines and nitrile oxides.