Heterocycles are an extraordinarily important class of compounds, making up more than half
of all known organic compounds. Heterocycles are present in a wide variety of drugs, most …

In this critical review, the ring opening of non-activated 2-substituted aziridinesvia
intermediate aziridinium salts will be dealt with. Emphasis will be put on the relationship …

The importance and prevalance of O-, N-, and S-atom containing saturated four-membered
ring motifs in biologically active molecules and potential therapeutics continues to drive …

One of the most widespread synthetic routes to coumarins is the condensation of esters and
phenols via the Pechmann reaction. Despite the industrial and technological importance of …

Aziridines (azacyclopropanes) constitute the well-known class of heterocyclic compounds.
The studies on synthesis and reactivity of aziridines have drawn tremendous interest of …

Azetidines (azacyclobutanes) constitute a well-known class of heterocyclic compounds.
Azetidine scaffold has been discovered in several natural products. Several …

An unprecedented and novel synthetic route to hexahydropyrrolo [2, 3-b] indoles bearing cis-
contiguous stereocenters with excellent stereoselectivities (ee of> 99%, dr of≤ 99: 1) has …

Recent advances in the field of ring‐expansion chemistry, involving 1‐azoniabicyclo [n. 1.0]
alkane scaffolds (bicyclic aziridinium ions) as key transient intermediates, have made it …

The inherent reactivity of the aziridine ring due to ring-strain makes it valuable building
blocks for the synthesis of other heterocyclic motifs of biological relevance. Of particular …

The ring expansion of prolinols via an aziridinium intermediate gives C3‐substituted
piperidines in good yields and enantiomeric excess, the substituent at the C3 position being …