I₂-mediated coupling of quinazolinone enamines with 2-aminopyridines: a new strategy to access spiroquinazolinones

Abstract

Umpolung is a powerful strategy in organic chemistry to construct complex molecules. Herein we report a novel, rapid and efficient route to spiroquinazolinone framework via an umpolung strategy mediated by...

Cu(ii)-catalyzed domino construction of spironaphthalenones by dearomatization of β-naphthols and using N,N-dimethylaminoethanol as a C1 synthon

“…Spirocyclic scaffolds are valuable structural motifs in pharmaceuticals, 1 functional materials, 2 and many privileged chiral ligands. 3 Transition-metal-catalyzed dearomatization of arenes has demonstrated to be efficient for accessing various challenging but appealing spirocyclic compounds; 4 however, existing limitations such as tedious preparation of specified substrates, high cost of transition-metal catalysts and sophisticated ligands, and harsh reaction conditions have somehow hindered its application.…”

Reductive thiolation and oxidative dehydroaromatization of cyclohexanones with primary amines and sodium sulfinates to access o-sulfanylanilines

“…Solvent screening demonstrated that H 2 O was the best choice, while DCE completely inhibited the reaction and CH 3 OH significantly decreased the yield to 54% (entries 2 and 3). Among previously used iodized salts, 15 KI, NIS and PIDA could not trigger this multi-component reaction at all (entries 4–6). Subsequently, the use of HBr instead of HI also could not deliver the desired product (entry 7).…”

“…Subsequently, a condensation reaction between B and primary amines generates the imine intermediate C , which could undergo tautomerization to liberate the key species D . Finally, the resulting enamine D undergoes a one-electron oxidation step, 15,18 deprotonation and sequential dehydroaromatization steps to furnish the desired product.…”

Photocatalytic C(sp2)–OMe bond cleavage and amidation of anisoles with N-hydroxyphthalimides and phthalimides

“…, azoles and ammonia) are suitable nucleophilic coupling partners in this photocatalytic system for the construction of N -arylazoles and anilines from methoxyarenes. Inspired by the advantages of the photocatalytic protocol 22 and in continuation of our own efforts on developing eco-friendly strategies for C–N bond formation, 23 herein we present a visible light-induced C(sp 2 )–OMe bond cleavage and amidation of anisoles with acidic N -hydroxyphthalimides (p K a = 6.1) 24 and phthalimides (p K a = 8.3) 25 using 1,2,3,5-tetrakis(carbazol-9-yl)-4,6-dicyanobenzene (4CzIPN, ) 18 as a mild oxidizing photoredox catalyst (Scheme 1d).…”