Dearomatization through Halofunctionalization Reactions

• Published in: Chemistry : a European journal Vol. 22; no. 34; pp. 11918 - 11933
• Main Authors: Liang, Xiao-Wei, Zheng, Chao, You, Shu-Li
• Format: Journal Article
• Language: English
• Published: Germany Blackwell Publishing Ltd 16.08.2016; Wiley Subscription Services, Inc
• Subjects: Alkenes; Alkynes; Architecture; arenes; Aromatic compounds; asymmetric catalysis; Catalysis; Categories; Chemistry; dearomatization; Enantiomers; Halogenated; Halogenation; Olefins; Strategy; synthetic methods; Transition metals; halogenation; asymmetric catalysis; arenes; synthetic methods; dearomatization
• ISSN: 0947-6539; 1521-3765
• DOI: 10.1002/chem.201600885

Recent advances in dearomatization through halofunctionalization reactions are summarized in this Minireview. Two general categories of strategies are currently employed in this field. On one hand, the reaction can be initiated with electrophilic halogenation at an alkyne or alkene moiety. The resulting halonium ion intermediate is then captured by a pendant aromatic ring at the ipso position, affording the dearomatization product. On the other hand, electrophilic halogenation can directly take place at a substituted arene, and the final dearomatization product is furnished by deprotonation or intramolecular nucleophilic trap. Highly enantioselective variants have been realized in the latter case by organocatalysis or transition metal catalysis. By applying these methods, various valuable halogenated polycyclic molecular architectures have been obtained from readily available starting materials. Not so aromatic now: Dearomatization through halofunctionalization occurs according to two pathways. The reaction can be initiated with electrophilic halogenation at an alkyne or alkene moiety, or electrophilic halogenation can take place directly at a substituted arene. By applying these methods, various valuable halogenated polycyclic molecular architectures have been obtained from readily available starting materials.