Thematic issue "Synthesis and transformations of heterocycles under electrophilic conditions”

The reactions of organic compounds with various electrophilic reagents are among the most effective methods of organic synthesis. The currently used set of electrophilic reagents is very wide and diverse: these are not only “classical” halogens, including derivatives of hypervalent iodine, but also all kinds of C-, N-, S-centered electrophiles, as well as Brønsted acids (HHal, H₂SO₄, AcOH, CF₃CO₂H, etc.) and superacids (CF₃SO₃H, FSO₃H, HF), Lewis acids (FeCl₃, ZnCl₂, AlCl₃, AlBr₃, SbF₅, etc.), conjugated Brønsted–Lewis acids, acidic zeolites. The use of such electrophilic reagents makes it possible to carry out many synthetically significant transformations, such as halogenation, hydrohalogenation, nitration, sulfonation, alkylation, isomerization, etc., leading to the valuable organic compounds. As a result of the electrophilic activation of the substrates, highly reactive cationic intermediates are generated, the subsequent transformations of which proceed with high degree of regio- and stereoselectivity, which makes it possible to obtain target compounds with preset structure.

Electrophilic transformations have been known for a long time and are widely used in the practice of organic synthesis; their methodology and theoretical aspects related to the reaction mechanisms and the reactivity of the intermediate particles have been fairly well studied. However, despite the results already achieved in this field, the development of new effective and interesting electrophilic reactions is still actively and successfully continuing, including the field of chemistry of heterocyclic compounds.

This thematic issue of the journal is devoted to the synthesis and transformations of heterocyclic compounds under the action of various electrophiles, Brønsted and Lewis acids. The main topics of this issue are the construction and transformation of heterocyclic structures, as well as the modification of substituents in heterocyclic systems under electrophilic conditions. This issue of the journal includes 8 review and 18 experimental articles.

On behalf of the editorial board, I would like to thank all the authors for taking part in the creation of this issue. My

special gratitude is devoted to the reviewers and the staff of editorial office, whose remarks and comments helped to improve the quality of the published manuscripts. I hope that this issue of the journal will be useful to many synthetic organic chemists, especially specialists in the field of chemistry of heterocyclic compounds.

Guest Editor of the thematic issue

Dr. Sci., Professor Аleksander V. Vasilyev,

Saint Petersburg State Forest Technical University,

Saint Petersburg State University