Synthesis of Benzopyrans by Enolate‐Directed Rhodium‐Catalyzed Oxidative C−H Alkenylation of 1,3‐Dicarbonyl Compounds

Abstract

Ad iverses cope of 2-aryl-1,3-dicarbonyl substrates was investigated in an efficient and facile enolate-directed CÀHa lkenylation process using readily availablee lectron-deficient alkenes. The developed domino strategy works under rhodium catalysis, providing ar ange of benzopyran heterocycles by the formationo ft wo distinct CÀCa nd CÀOb onds and one new six-membered ring. The salient features of the protocoli nclude the broad range of previously unexplored 1,3-dicarbonyl substrates for CÀHa lkenylations, good functional group tolerance and rapid assembly of new benzopyrans in generally good to excellent isolated yields. Figure 1. Selected examples of bioactive benzopyrans.[a] Dr.

Styryl Group, a Friend or Foe in Medicinal Chemistry

“…It is used as a dienophile in Diels‐Alder cycloaddition, [30] its annulation with allenes produces chromenes [31] benzoxepines, [32] spirocyclic enones, [33] and polyaromatic frameworks [34] . It is used as a key precursor in oxidative coupling with alkynes/ arenes, [35] and cyclization of amidine to a pyrimidine [36] . Furthermore, the substituted styrene such as β‐nitrostyrene acts as a Michael acceptor [37] …”

Research Progress on the Synthesis and Structure-Activity Relationship of Five Hypoglycemic Active Heterocycles Based on Dipeptidyl Peptidase 4 (DPP-4) Target Design

“…The specific synthetic route to ketone[4,3-c]quinoline-6,11-dione is shown in Scheme 10. Bollikolla et al [45] also used the [RhCp*Cl 2 ] 2 as catalyst for the synthesis of benzopyrans by C-H bond activation in 1,3-dicarbonyl compounds through OH-directed Rhcatalyzed vinylation. The specific synthesis route is shown in Scheme 11.…”